Active Cooling Fan Duct v2 for Replicator 1 / Duplicator 4 / FlashForge / CTC

by thruit00, published

Active Cooling Fan Duct v2 for Replicator 1 / Duplicator 4 / FlashForge / CTC by thruit00 Nov 13, 2014
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Please read this text completely before printing!

This is an improved version of thing 295317


Fine detailed parts of your prints (PLA and ABS) normally don't show up well and and bridging only works for small distances if you use your printer like shipped from the manufacturer. This is because a fundamental part of your printer is missing - the extra cooling fan (duct). On some of the prints you can slow down printing speed as a workaround for this problem but you will not get very fine details or long bridges to match your needs. The goal of this duct is to create the best possible solution to avoid this problem without any real drawbacks.


This active cooling duct is designed to work on the following MK7/MK8/MK9 Dual Extruders:

  • MakerBot Replicator 1
  • FF3DP FlashForge Creator
  • CTC Creator Dual
  • WanHao Duplicator 4 and Duplicator 4X

Improvements compared to v1

  • Higher air flow rates especially on the side channels
  • Less air loss between fan and duct
  • Only screws and nuts are required which are available in every hardware store
  • Duct will be mounted horizontally and solid - enough space for small buildplate clips
  • More flat center air outlets to avoid contact with heatblocks
  • Angular fan mounting allows usage in Duplicator 4X with regularly installed and closed front door and avoids previous known crash problem with front door nuts.

Downsides compared to v1

  • More complex bridging requires better optimized filament profiles
  • Because of the thin walls for low duct weight you will need a temporary cooling solution to get the duct printed well. Printing it with an installed v1 / Thing 295317 works flawless. Not as good but also a good chance provides my ordinary duct for flipped extruder fans but there are other good cooling solutions out there allowing to print this duct.


All of the above mentioned printers have one thing in common - they use an almost similar ABS extruder carriage. From the bottom side it holds 4 linear bearings in every corner and from the top it has 2 small slot-holes at the front (and 2 at the back) of the carriage. Unfortunately the form of the mold differs a little bit and so the carriages do. The upper list of printers I own or have access to and I found a way mounting the duct which works on all of them.
First you place a M3 nut in every outer arm of the duct. Insert them from the sides. If you turn the nut the right way it should not require any force. Now you snap your fan into the back of the duct. It's a close fit and it should immerge 5mm on every side into the side frame. Now attache the 2 other nuts into the matching slots at the front of the duct and screw the M3x16mm screws trough the fan into the nuts.
Now you place the duct in front of the extruder carriage. Make sure the small lobes on both sides grab the carriage from the bottom near the linear bearings. Now attache the printed clips with their hexagon connectors to the top of the side arms. The clips should be directed to and grab into the slot-holes of the carriage. Now screw the M3x12mm screws from the top through the clips into the duct body. At the end you should achieve a very strong and close fitting duct in front of you carriage and the bottom of the duct should be installed perfectly horizontally.


  • 2x the printed clips
  • 1x the printed duct
  • 1x 40x40x10mm fan with 24V if you want to use the normal power supply as source
  • 2x M3x12 countersunk head screws
  • 2x M3x16 countersunk head screws
  • 4x M3 nuts
  • 1,5m twin power cable from the printer bottom along with the other cables to the extruder to supply power for the extra fan
  • a solution to switch on the cooling fan only when you need it

Cooling fan power source

A simply way would be to directly take the power for the fan from the power supply and install a simple on/off switch in between. For the first few (1-5) layers you should leave the fan switched off and switch it on afterwards. This manual switching solution works but requires a lot of your time waiting in front of the printer.
A much better solution is to control fan power with the MightyBoard you have in your printers. If everything is setuped perfectly you can control the fan via GCODE. Any good slicer is capable of inserting the fan control commands automatically. If you use sailfish firmware, which most of the advanced users use anyway, you can also control the cooling fan from the printer menu. For this you need the so called EXTRA connector on you MightyBoard. This connector and the required MosFET Q6 are often not soldered on the board.If you are a soldering expert and aware of the risk of killing your MightyBoard and losing your warranty, you can solder the missing part Q6 which is a MOS-FET named PSMN7R0-30YL (bought mine on the most famous online auctions platform) and an additional power connector to your mighty board. One of the pictures above show my modified board. Don't blame me, if you fail on doing that! MosFET mod

Active cooling for PLA and ABS prints

Some people think cooling is something you only need for PLA prints. They say on ABS prints you destroy your print because of warping if you use an active cooling solution like this one. I can promise you, that this is not true! For further instructions how to avoid warping please read How to avoid warping chapter of instructions tab over here.

Printing Instructions

See Instructions tab for further details on how you should configure your slicer


All trademarks mentioned belong to their respective owners. Modification of your device might result in a full loss of warranty.


Even though a duct like this should be installed on every printer directly from day 1, this optimized model is not easy to print for beginners and you might need the expert mode of you slicer configuration.

For experts I keep it short

  • 0.1mm layer height
  • 100% infill
  • 2 shells
  • ABS filament
  • good cooling while printing

Some more details for the rest


If you want to print ABS parts later on with this duct installed you should also use ABS as material to print the duct with. This is because the melting point of PLA is lower and the duct is installed near the hot ends of your printer. For ABS printing you should be able to close your cabin (front and side doors + top cover or at least a reversed carton box over the whole printer and filament rolls)
Because this duct has very fine walls (to achieve the required low weight) and long bridging parts you need to tune your slicer profile perfectly well for you filament.

How to avoid warping

If you have warping issues, your bed is not flat, you bed or extruder temperature is not matching your filament, your ABS filament quality is bad or you use the wrong build plate material. If you use a real flat aluminum build plate and clip (with small metal clips) a 1mm or 2mm [FR-4 fiber board][2] to it (which you are sanding once with a type 400 sand paper before) you will have the perfect build plate for ABS and PLA prints. Now you only have to find good ABS filament which doesn't has to be expensive and optimize your slicer filament profile for it. Prints on the FR-4 fiber plate adhere pefectly while printing and detach automatically when build plate is cooling down.


My favorite slicer is Simplify3D but I try to describe the further steps independent of the slicer in use:

Extruder temperature

You can use a simple test cube to tune your profile. Lower the extruder temperature to the lowest temperature your filament is still continuously flowing.


Configure your profile to create 2 shells.

Filament diameter / filament feeding

The smaller a value inserted into the filament diameter field of your slicer the more filament gets extruded. Configure your filament diameter to the highest value where your shells are still binding. Even if your filament diameter is advertised with 1.75mm typical variances of your specified diameters are somewhere between +0.09 and -0.05 mm and you mostly require 3 digits after the decimal point to specify the perfect diameter. Measuring your filament will not be enough - you will have to fine tune it with try and error.

Infill to shell overlap

Now you have to tune your infill to shell overlap. Common values are 10%-20% of your nozzles diameter. You can print the test cube with 100% infill and lower the overlap to the lowest configuration where the infill is still binding to the shell well.


Now you need to optimize your bridging. For this step you should download a good bridging test model from thingiverse. First thing you need for bridging is active cooling. So if you don't have a cooling duct already, you should at least print a temporary one like this and in this case reverse (turn) your extruder fans to blow at your duct. This simple duct is not as good as the one you are going to print in this thing, but it helps you to print the first one and you can print a good one afterwards with it. Except for cooling you might want to configure your printing speed while bridging to a value where you bridges are as good as possible.

The design of this duct is optimized for common 0.4mm nozzles and a layer height of 0.1mm. If you have trouble printing the first few layers with 0.1mm or you run into warping problems don't forget to read the How to avoid warping chapter in this instructions tab over here.

Which files to print:

Please don't be too harsh on me, if you run into problems printing this duct. It's printing fine on all of my 3 printers and subsequently you have to tune your printer, your slicer knowledge and/or buy better filament.

Good luck!

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Printed just nicely, but maybe two suggestions for further improvement:

  • The top wall for the fan does often end up as loose strands and isn't even needed because it blocks the way for the cable.
  • Those "mounting nuts" easily break loose and the cylinder below them also isn't really fixed in place, it can also break loose when trying to move the nut in the right place. Might be just a slicer error causing that instability, but I think that this part could be designed better.
Sep 15, 2016 - Modified Sep 15, 2016

Do you know how much mA should the fan be?

Hi, I've printed this for my CTC and ordered the Extra FET PSMN7R0-30YL for the Mightyboard.

Can anyone please confirm the simplest way to present the new fan to MakerBot Desktop? My goal is to have the fan control identical to my Replicator 2, which is constantly tuning the part fan speed, to good effect. I am very familiar with custom profiles having worked for a MakerBot distributor, so I'm just looking for a success story doing exactly this.

Jul 5, 2016 - Modified Jul 5, 2016

I don't know if this is a mistake with the type of fan that I bought or it is something with the mighty board, but in order to install this duct on my FlashForge Creator Pro 2016 I needed to uninstall the side fan mount and buy a new fan because the already installed side fan was not compatible. The fan that I bought I believe is the same one that is mounted for the extruders, but when I connected the fan to the two pin connector that the previous fan used nothing happened. The fan would turn a tiny bit then stop. I checked everything and they were the same exact specs as the previous fan, DC 24V, 0.1 AMP, and brushless. When I would reconnect the previous fan everything would work fine. I checked with my multimeter and the voltage coming out of the two pin connector is 24V, as it should be. Sorry if this is a really dumb question. What might seem as a really easy fix for you has really got me stumped.


I connected the fan using another method to verify that my fan wasn't broken and it isn't. I connected a power supply to an outlet and the fan to the power supply and everything worked fine, yet when I connect the fan to the printer it still doesn't work.

Sep 11, 2016 - Modified Sep 11, 2016
shocksofmighty - in reply to ikiya13

Polarity matters in this case. I noticed this when I replaced my fan on the FFCP2016. I figured the fan should run backwards if I connected it in reverse, but that wasn't the case.

Also, if you want to use the stock FFCP2016 side mount fan, I made an extension duct that will do that. It includes a damper to restrict air flow to one of the extruders if desired. http://www.thingiverse.com/thing:1753983

2016 FFCP Side blower fan adapter for thruit00's active cooling duct, now with damper for extruder selection

did you get this fixed? i'm about to buy the parts for my 2016 but won't bother if the extra connector isn't wired up or whatever.

I just finally added this mod to my 2016 FF creator pro. Worked perfectly. Removed the side fan, bought these from amazon https://www.amazon.com/gp/product/B00NWGM54S/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1 and installed like a dream. Even has the same connector as the removed side fan, so there's no need to worry about wiring. I use simplify3d and it works as expected. I set the fan to turn on after layer 5 to make sure i get good bed adhesion, and it turned on and ran as it should.

Yes I got this fixed. I don't know whether this was a problem with my fan or with all fans, but the way the wires were hooked up to the connector were different. For example if the pre installed fan was hooked up to the connector with red first and then black, my new fan was hooked up black first and then red. All I did was cut the wires on the fan and then switched them. Again I don't know if this was just a problem with my cam it with all fans but this is what I had to do to fix it. Hope this was helpful.

thanks for the reply @ikiya13 does it actually fit though, a lot of people are saying it melts on the extruder or something on the 2016?

So far it fit just fine and it hasn't melted for me.

I've made this duct in 2014 and it is an upgrade to the duct I made in 2013. The ducts are designed to work on a Flash Forge Creator, a CTC Creator Dual, a Wanhao Duplicator 4 and a Makerbot Replicator 1. I can't support other printers than the ones I have sitting at home and I can't design things to be compatible with printers which are designed 2-3 years later in time.
If you newly bought fan works with a 24V power supply directly it should work with the MosFET on the mightyboard. If not I only can imagine that the situation is one of them:

a) Flashforge might have changed the mighty board to provide a different voltage on the extraFAT output now. You can disconnect the cable from the extraFAT on the mighty board and measure if the voltage on this output is 24V if the fan is switched on via gcode or sailfish firmware printer menu.
b) The cable from the mighty board to the printer head might not be a simple cable and e.g. holds a resistor in it to reduce 24V voltage from mighty board to a 12V fan (which is much more affordable in production). Because of the inductive load of a fan a voltage divider with a simple in line resitor is dirty and would only work if the fan voltage AND current of the replacement matches the one on the original fan. If they would have installed a resistor in the cable, you could test if the fan directly attached to the extraFAT output at the mighty board works, than you know its the cable. Measuring the voltage at the printer head side of the cable will not help if they really would have uses an inline resistor as a voltage divider - you still would measure 24V because the resistance of the multimeter is extremely high and the potential difference is relative to the resistance on which you measure.

This might not be a direct solution to your problem. It just might give you 2 new ideas what to check next.
Kind regards,

I have uninstall left extruder on my CTC Dual.
Are you able to make same cooling duct for only right nozzle?

Unfortunately no. I only support the printers and setups I have at home.I'm very busy and I design things for myself and offer the STL files to other people freely if they work for them out of the box. In your case you need to use one of the remixes people did (http://www.thingiverse.com/thing:1047230 or http://www.thingiverse.com/thing:952594) or draw your own duct.

Active Cooling Vent (Right Side Only) Replicator/Duplicator/Creator/CTC
by rdahm
Active cooling fan for Flashforge/Makerbot/Etc - One nozzle only!
by Bassna

thanks. it has helped.

I noticed that you got extra red aluminium parts on your build platform where can i get such part to make my ctc much stabile ?

and what do you use as build plate ? some buildtalk or something else ?

Google for 'Home Zillions Platform Hanger' and you will find ebay links for them. The new version has a different color but directly fits the ctc. The old version you had to drill aditional holes for the ctc first. They are cheap and shipping is slow but along with the cooling duct and the fr4 build plate they are one of the 3 most effective upgrades. Of course as a fourth upgrade a fully closed printer cabin is a must have, if you want to print abs.

Jul 6, 2016 - Modified Jul 6, 2016
thruit00 - in reply to bogas

Hi bogas,

The material is fine but it's a little to thick. I use white FR4 plates with 1mm. Depending on the bottom surface and the filament you use the model might glue to the plate and will not automatically detach when cooling down. In this uncommon situation you need to detach the print plate along with the model from the printer heat bed and bend the plate a bit so that the model detaches. So it's important to use cheap '19mm foldback clips' to attach the plate to print bead and not glue it to the bed! Having a FR4 plate which is much thicker that 1mm bending would not be so easy! The other problem is that the price in your link is much to high for a material you need to rework on your own. In Germany you can buy them for around 10€. If you don't want to sand and cut them on your own you can buy them perfectly sized and prepared at www.3dprinterstore24.de but I don't know if they offer you an English version of their shop UI if your browsers language is configured to English.

Just give it a try (this is the link to the plate for a Replicator 1 or clone with a print bed of 230x150mm):

On their shipping costs page they talk about shipping costs to Germany and shipping costs to none-EU. But as long as you are still in the EU I think the shipping costs to the UK should not be a big deal.

If all of the information on the page is German you can write an email to [email protected] and I'm sure they can help you in English as well!

I'm not related to the store and don't get any profit from it! I just bought some of the plates for my printers from this store and some others I made on my own. Don't buy the normal version in this store - you need to buy the special version! It's all about the roughness. The special version is sanded with K80 instead of K160 and it's adhesion is much higher wich is neccesarry if you want to print tall models with low surface binding. It's available in the store because I wrote to a lot of people in different forums that they need to order it sanded more rough by writing a comment when ordering the plate. So now the store decided get rid of the extra ordering comments and offered this 'special' version and raised the price for it a little at the same time. A perfect example on how free market economy works :-)

Kind regards,

Oh my God. This thing is amazing!

Awesome Design & print. A+++. Work exactly it supposes to.

Great work, fits perfectly on my Replicator 4s (2016)!

hi thruit00

I got ctc printer from two weeks but i struggle with settings in Simplify 3D and also even if i change setting for Y axis to proper one simplify did not write it back to firmware even if i choose save every time when i open simplify its the same like in X axis ( i try to change it because when i print 1cmx1cm cube i see a difference in dimension about 0.3 0.4 mm on Y axis )

and of corse extruder always clicking even with slow speed and high temp so i'm not shure if my fff profile is good

is there any chance that you can send me your settings for ABS and PLA for this dual nozle printer for simplify 3d ?

regards Michal

for me this does not sound like an s3d problem. problems like this often occur if people switch from default firware to the much better sailfish firmware and forget some steps of the installation instructions. if everything still works in your other slicers. doubke chevk that you've selected "Makerbot/Sailfish" in your Firmware configuration in S3D and selected "Replicator 1" in its x3g tab. Leave all the default values concerning steps per mm and toolhead / heating.

Hi, I'm kind of a newbie to 3D printing, but how do you do the software modifications for the fan to work. I'm currently using the Qiditech1 which is basically a clone ofthe Creator Pro. I've soldered on the terminal blocks and the connections as per what you showed. The slicer I'm currently using is the Makerbot Desktop 3.7 and I've added the "doFanCommand" to the miracle file. But when I start printing and use the multimeter to check it keeps showing 0 Volts. Is the issue with the slicer? Or is it a hardware issue? Or something else all together? By the way the MightyBoard already has the MosFET soldered on.

I switched to simplify3d before makerbot renamed their slicer from makerware to makerbot desktop. But fan did already work in the old makerware, so I would expect it to work on desktop as well. If you've upgraded to sailfish firmware on you MightyBoard, you can directly switch on and off the fan via printer menu. Of course this is not the way you will use it later on, but it helps to find the problem. If I remember it right the gcode to controll the fan is M126 to switch it on and M127 to switch it of. If you choose to export to gcode instead of x3g, you should find this commands in the code. Good luck!

It didn't fit my WD4X; just sanded it down a bit and it worked fine.

Fits my WD4 from 2013 and my colleagues WD4X from 2014. But I'm not sure how production details are going to change from year to year. I've read that it fits current WD4s - even though it has a steel rod. Unfortunately I can only support printers I have around me. To make a thing releasable it costs me about 50 iterations, where I print it install it to the different printers, check airflow and make sure it is not getting to hot somewhere that it would melt after a while. Unfortunately no manufacturer is sending me a free device to make my parts work :-) If I would count the hours I spend, providing me with a printer would realy be a cheap price per working hour.

This comment has been deleted.

there has been one user once who had the same problem but exept for him and you, nobody complained before. It might be microswitch related. Maybe bending the steel spring a little may help to solve the problem. I'm sure we talk about fractions of a millimeter.

Does adding this hit the front plexiglass on the FlashForge Creator Pro (2016) model?

don't know. It fits to my replicator 1 clones from different manufacturers from 2013 and 2014 so tht I can close the doors with this duct installed. As I'm mostly printing in abs this is a key feature but I only can support printers I own.

Good question.

Great thing.
I would like to mount it from the back in order to have free sight to the print.
The outlet must be extended 12mm for that.
Also, as further improvement, i would like to try to lead the
air more downwards to the print instead of cooling the nozzles.
Then, i like to implement a 70mm LED Cob-ring for illumination.

Could you please provide the CAD-data for a remix?

Sure would be nice if he would because this sucker has over 400k triangles to it. I reduced it to 19900 and it was perfect but I am not going to waste weeks reverse engineering this so I might as well make my own from scratch. My thing is I demand more airflow as I can see a lot of backflow on this design.

Good Point.
Instead of struggling with vage Vertex-Clouds,
it might be less frustrating to make one from scratch.
I believe that a radial fan blower will be the way to go.

I apologize if this is a dumb question, but when you say "1.5m twin power cable from the printer bottom along with the other cables to the extruder to supply power for the extra fan" does that mean a separate cable that we must purchase, or is that something already installed in the printer? Thank you!

Wish there was a solution to have the cooling come in from the sides like stock blower on the left nozzle, that way I can see the nozzles and have access to them during prints

not sure where I went wrong... but I had to print the two clips 5% larger vs the rest of the fan duct so they would fit onto it.
Otherwise, did an awesome job.

In CAD the parts are designed to have a clearance of 0.2mm in each direction. This means if it would be a perfect molded part the diameter of the nut bold would be 0.4mm less wide than the clips cut out. If you end up the other way round you have a over-extrusion problem. If you print a 100% infill calibration cube with the same profile, how is your end result if you measure it?

Apr 9, 2016 - Modified Apr 11, 2016

okay printed and fitted. Doesn't need the clip, like the design and have to say it looks a lot more professional in place than the first one did :-)
Many thanks :-)

Only thing I'd change is to move the bottom wedges so that the duct fits in perfectly centered. Yeah you can slide it along by eye - but would be much easier to make it self centreing.

And you can print at 0.2mm with no problems. Changed both my mk1's for mk2's now. Not sure they do blow more air, but damn they look a lot cooler :-)
Good job and thanks for making it available to the rest of us :-)

The bottom wedges and clips have been changed a lot of times before I released this version. Reason for the clearance is, that I wanted to design a duct which fits all of my Replicator 1 clone printers at the same time. Unfortunately the cartridge design differs from Replicator 1 clone to clone.

does it work with the adaptor clip for the mk I ?

Simplified bracket for Active Cooling Fan Duct - CTC / FlashForge

No, you don't need them in combination with this duct. This Clips is for v1 of this duct.
What do you mean by Mk I? Makerbot Generation one? This would be Cupcake CNC from 2009? Answer would be 'no'. None of my ducts fits this printer.
If you mean Makerbot Replicator 1 - which is a Generation 3 Makerbot from 2012 - answer should be 'yes' it should work directly without the extra clip you linked.

I'm using this with my MK10 Micro Swiss All metal hotends which replaced my stock MK10. I've done one successful print at 220c of the massive overhang testprint with this fanduct installed. No warping of the ABS in the duct. And there is no contact between the nozzles or heatblocks and the duct. I'm really happy with the duct so far.

This is a little surprising for me. Thanks for the info! I would have expected too much heat from the bigger nozzle to the duct!

Is there a plan to make a version of this compatible with the side fan they've started including? Having the fan is nice, but the end they have on it leaves a lot to be desired.

Unfortenately the answer is no. I experimented a lot with different types of fans. Side and and rear mounted axial and radial fans of different sizes. All had its massive downsides for me. My designs are made for my own printers and if I think its really a big benefit I offer to download the design to the rest of the world. So most of my designs where released a long time after I did the first draft.and after a lot of alpha and beta versions have been printed and tested on about 10 different printers I called them stable enough to release.
Things I don't want to miss on my printers are:

  • Steel stiffeners for the Z axis arms (they do cost a little headroom at the back and disable the chance of rear mounted fan ducts)
  • FR4 long therm build plate with small steel clips (for this you need a little headroom beneath the duct to not crash the duct into the clips)
  • Front and Side doors + hood to allow ABS printing without warping ( this limits the size of the duct to the front)
  • full original build area/volume
  • dual extrusion (both of the last together kill the ability to mount side fans)

Does this adtive fan hit the plexiglass front on the Flashforge Creator Pro?

Didn't actually think my CTC 3D printer would print this tbh but your design is perfect, you nailed it. Thank you so much. Now to install a fan. Best fan duct I have seen to date :D

Printed installed and tested great thanks for the good work!!!

Nice fan duct! Put it on my creator X and with minor tweaking, I can bridge ABS almost 50mm. This will definitely make a big difference in my prints.

Great and thanks for the feedback!

I find on my FFCP that the heater blocks touch the duct and melt it.

You might have a new model with mk10 hotend. This duct only works for all hotends until mk9. I have no printer with a mk10 hotend cause for me this is a downgrade, compared to the mk8 nozzle construction. You need to find an other cooling solution or design your own one like I did. Sorry for the bad news!

Thanks mate.

it seems very good. by any chance can you share the step file of the design? ive a DIY printer and ive to find a way to connect this thing onto it? but i can edit stl files. if i cang et get a step file ti would be perfect.

My Flashforge Creator Pro came with a "turbo" side mount fan already installed which seems to be an upgrade as of 2015-ish. It only covers the left extruder and is not really that good. I have not seen any mention of re-purposing "this already wired and installed fan" to this version of a fan duct. I would assume since this extra 3rd fan is already wired in, it can be just moved from it's current side position over to the front of the extruder assembly and its easy money from there......no?

Mission Complete. I like this cooling duct way better than the MMF one as far as design and functionality. My FFCP came with the "turbo" fan already installed and wired in but it only covered the left extruder and it also pointed down, not across the print. I printed the V2 cooling duct here with no issues and it came out fantastic (maybe cause the turbo fan helps actually and the FFCP does a great job with overhangs) I bought a 40mm fan off Amazon and was able to direct plug it into the same plug the turbo fan used to be plugged into. NO NEW WIRING NEEDED! One thing I did have to change was the plug on the 40mm replacement fan was wired backwards so I had to reverse the pins.

I use simplify3d (since it is amazing and well worth the money) and since the FFCP profile it has is already turning on and off the turbo fan after the first layer, it was ready to go with no other mods.
Thank you for making this possible. It is awesome and already my prints look amazing!

I've done what you've done. I've just changed the white cable connector from the old side fan to the new front one. However it does not work. Do I need to reverse the pins like you did?

Thanks for the warm words and the information concerning the new turbo fan setup. I don't have one of those printers, so it was really new to me!

I just got a Powerspec Ultra 3D Printer, which is basically a remake of the flashforge dreamer, both use the same dual extruder I think (mine has the fan as well on the left side). I'm almost certain it's fine to repurpose this fan, as the extruders have their own fans already. I'm going to try this tonight and I'll let you know!

I too have the Powerspec Ultra with the fan upgrade, and printed this part today with the intention of moving over the existing fan. Did you print yours in PLA or ABS? I'm a little concerned how well it will hold up close to the nozzles made out of PLA, but I only print in PLA due to indoors and the toxic vapors of ABS. Interested to know how yours is holding up? Did the clips work as-is?

I found another version of this cooling concept on MMF and it is made specifically for the side fan we are talking about. I'm going to give it a try since it mounts with existing hardware and I'll let you know!

Feb 25, 2016 - Modified Feb 25, 2016
jasu - in reply to iDo3DPrintz

I had a look around for the models that Av8rT0M referred to. On MMF I found 2 files that roughly match your description.

One from Flashforge. It's a 1 part fan duct.

The other one from Mark Ledwold. It has 2 parts only one of which is on MMF.

Which one are you testing and why did you choose it over the other? Any tips regarding the printing and mounting?

I also found this design by Markwal which keeps the fan on the side and probably cools filament coming out of the closer head more than the farther one. It's a 2 part design.

FlashForge Blower Fan Duct and Mount
by markwal

This duct works great, I had to print it at .2mm, and was planning on reprinting it in .1mm afterwards but the thing works so well I decided against it. One slight issue is it sits pretty close to the extruder...so it has gotten scorched, but hasn't seemed to be harming it more than that.

You might have MK10 nozzles which are wider that the MK6, MK7, MK8 and MK9 nozzles the duct was designed for. I don't have a printer with those mk10 nozzles cause I prefer the better headroom (they are higher and less wide) of the older nozzles.

This comment has been deleted.

Does this fit Duplicator 4S with MK10 extruder ?

It fits but the outlets might melt a little because it was never designed to work with them.

Feb 9, 2016 - Modified Feb 9, 2016

I printed one and it works great, just using a switch for now.

I am ok sourcing and soldering the missing mosfet (the connector is already there) but I don't know how to control it via GCode.

Is there a tutorial for this? do I have to manually edit each file to add the code to turn on/off the fan or can it be done in the Slicer? (I'm using Slic3r and Sailfish 7.7)

All slicers I'm familiar with already have the gcode control of the fan build in (configuration of course differs). You even can control the fan via sailfish printer menu directly while printing, but this is not better that using the switch you have integrated right now.
The big advantage of gcode controlled cooling fan is that you can configure it in your filament profile and walk away after clicking start to print. I use Simplify3d (awesome slicer!!!) for my daily work and typically have my profiles configured to switch on the fan at layer 5 automatically.

what program did u make it with i whant to remake it so it fits original fan on flaschforge dreamer

I don't offer any models. See my previous justification on that.

Every time I try to open the clip file Win 10 explorer crashed. I think the name is to long. I'm trying to re name it but I can't :(

'open' in browser or in slicer? It works with Firefox and Chrome. Other browser I never tested. Clip-STLs are pretty small, so with slicers I would not expect any problems and did not hear any complains before.

Disregard my last question, Simplify3D has fan controls right in the standard configuration options (for some reason thought those referred to the extruder fans). The fan duct works great, I see quite an improvement on any build with overhangs.

Thanks and sorry for my slow reply :-|

This is a great design, thanks for publishing this, I just printed it and it came out great. I hope you don't mind a noob question, I recently bought a Replicator 1 clone from Monoprice, and upgraded to Simplify3D (the suggested ReplicatorG just doesn't print as well). Does anyone know how I can configure Simplify3D to have it turn the extra fan on at a specific layer (or what the G-code command is to turn it on and off for the Replicator 1)?

Did you have to components on the board, or where they already there? Did you follow any specific tutorial? Thanks for the help.

The mightyboard that came on my monoprice printer already had the output transistor included, so all I had to do was solder a longer cable to the fan, run it down the cable tubing, and I bought some of these connectors: http://www.amazon.com/gp/product/B00GWF65WY?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00 to attach to the end of the wires so it would plug into the board. I didn't follow any tutorial, it's fairly straight-forward.

That is my question as well.

Sorry for the slow reply. You can control the fan manually via Sailfish firmware printer menu (typically for testing) and normally all slicers can directly control the cooling fan, ehich means the insert the necessarry gcode into the code. Bad slicers only allow to 'use fan / enable fan' via a checkbox and all the better ones let you decide on which layer you want it to start. E.g. in Simplify3D you can also configure to only use the fan if the layer printing time is less than an amount of configurable seconds or/and if printer is doing bridges. But typically you switch it on after the first few layers (e.g. 5) and leave it on for the rest of the print. The default end gcode stops the fan automatically.

Other than ordering them online, where can one find the required M3x12 countersunk head screws, M3x16 countersunk head screws and the M3 nuts?

In Germany you can find them in every hardware store but if you live in a British influenced colonies/country where metric system is still not common, you can buy any M3 screw and shorten it with a steel saw.

I got mine at Home Depot in the hardware section

Ace Hardware carries metric screws.

hi all getting the following using recommended infill layer etc on replicatorg 0040 ( repeated a few times on diff layers) :
[20:51:24] 36672 [21327] [15387, 15388]
[20:51:24] Something will still be printed, but there is no guarantee that it will be the correct shape.
[20:51:24] Once the gcode is saved, you should check over the layer with a z of:
[20:51:24] 40.05

obviously a lot of prints have come out OK so must be a setting on my side or safe to ignore can anyone advise ? thanks

Jan 7, 2016 - Modified Jan 7, 2016

Hallo Gemeinde! Mit welchen Einstellungen druckt ihr die Lüftung?
CTC 3dPrinter
Gruß Maik

Please see my instructions here on this thing. I did my best to help you guys printing my duct. If you read it completely, you will find the information on how I printed it and how you can achieve a good printing quality. As this is an English speaking website and community, we all should give our best to ask questions and answer them in English.
Kind regards from Stuttgart, Germany

Greetings, I printed one just fine but unfortunately I have a geeetech prusa i3 C. This model has the dual mk8 but it is turned around so the back of the servos face the front of the unit. I've been trying to figure out how to extend the duct work to fix this issue but I've had no success. How does one normally modify something like this that is close but not quite what is needed?

Feb 25, 2016 - Modified Feb 25, 2016
thruit00 - in reply to riftware

Modifying complex stl is almost impossible. Because I can't offer the original models you need to draw it from scratch. When I did the first version of this duct I started exactely like you. I had an idea what to change compared to other ducts only available as stl and access to a PC with a licened CAD tool, but no clue on how to use it. After a 3 evenings with google I was expert enough to create the duct. Terrific new world - learning is so easy! Time killer started when I was optimizing the duct to improve its performance. This took me about 50 prints and model changes. This is why I only offer models I did for myself, but don't create models for printers I don't have.

great work!
The duct came out fine and without problems.
The tip with external cooling for the print was pretty essential.

The clips came out too small. The nut size was 1mm short.
Had to scale the clips to 117%. Any idea why the duct is ok and the clips are not?

In CAD the parts are designed to have a clearance of 0.2mm in each direction. This means if it would be a perfect molded part the diameter of the nut bold would be 0.4mm less wide than the clips cut out. If you end up the other way round you have a over-extrusion problem. If you print a 100% infill calibration cube with the same profile, how is your end result if you measure it?

How much filament is needed to make this and the 2 x clips please? Just want to get a small amount of ABS initially to get this printed. Thanks!

even with full infill you will only need a hand full of grams but if you don't have your printer optimized for this ABS filament you will need some kg spools for it and typically you will have to upgrade your printer to not end up with warping problems.

i think mine came out to be about 10 meters, but i didn't do the full infill

Cheers dude!

The hardest part for me was finding the screws, Home Depot and Lowes were a miserable experience trying to find exact lengths, and they suggested I buy longer length and cut them down by hand. In the End I bought my screws and bolts from


Printed out on Flashforge Creator Pro first time. Fits nice and tight. Just waiting on fan and connector.


I am using wanhao D4S metal frame version. I 3D print this duct and attached to my printer now when I start printing the fan duct fan duct Impinge with paper clip that is used to hold glass plate on heated bed. Is there any solution available for this problem ?

Just printed on my third day using the printer. Works perfect and i'm getting better results. Just waiting for the FET to turn up for auto control.


Perfect first try, Thanks! Fits perfectly on my CTC :)

Anyone have the problem of the fan not turning OFF? I installed the MOSFET and fan on my Flashforge Replicator Dual. I assumed any mistakes in soldering would result in a fan that does not work (or worse a bricked board). The fan runs whenever the printer is powered on. I can install a bypass switch, but I was hoping to control via gcode. Thanks for any advice.

BTW I'm running Marlin firmware and Makerware slicer. Setting fan to OFF (or ON for that matter) using the onboard controls doesn't have any effect either.

How do I hook up the power supply on the flashforge?

It really doesn't sound like a soldering problem. Never tested Marlin on a mighty board because I'm a big fan sailfish firmware and would also install it on a RAMPS based printer if available (because of better acceleration calculation). Anyways this should not be a advertisement post for sailfish firmware but the advice to test a regular firmware (Makerbot or Sailfish) first, to make sure your problem is not firmware related.

Whoops, I feel dumb. I'm running Sailfish (after all the trouble I went through to install it, I should not make such mistakes!). I was in the midst of researching multiple firmwares and had a brain blip.

Well thanks, I'll keep looking at software/firmware solutions.

Hey! I just printed one of these and it fits perfectly. Thanks! I'm trying to source the rest of the parts, and it occurred to me that I didn't know what gauge wire I should be using... What did you use? 18ga? 12?

Thanks again!

Nov 15, 2015 - Modified Nov 15, 2015
thruit00 - in reply to Gandarewa

We are talking about the fan wire, right? The fans I personally use are PAPST 414F they consome 30mA at 24V. So we talk about a VERY thin wire which would be big enough. Keep in mind that the wire is moved together with the extruder and it should be very flexible. So you should use a twin full copper (OFC) litz wire.

Hey awesome piece but I was wondering if you could post the cad file for it? I want to mount your cooling duct to the rear of the carriage so I can have clear view of the nozzles from the front. Currently, mounting it to the rear crashes into the 3 z-axis rods. I like your design the best out of all the other ones I found because of the aesthetics and how well it works. Thanks!!!!!!!!

Hi, thruit00 ,can you please public solid models?
I want to use my bigger Fan on your design.

Alright I'm going to print this on my Rostock max v2, but I just want to clarify on how to connect this to my motherboard off the Wanhao D4X: I just get the fan, and run my wires all the way to the board, I use S3D as well, but what is this fan switch you propose, i thought the new verison of sailfish has this in the settings to control said fan? Please be detailed and/or post a link of a demo video on YouTube. Thanks in advance.

The software/firmware side is not the problem. Even the regular firmware can handle the M126/M127 gcode commands and all good slicers (including S3D) can insert this commads into the gcode to switch on and of the fan on the configured layers. (Sailfish only adds the possibility to manually switch on and of the fan while printing in the printer menu).

The big thing to do is to solder the SMD MosFET transistor and a 2.54mm connector to the MightyBoard. I tried to describe this in this 'Thing info' over here. But to extract this information as an answer, what you need is the connector (this one is called differently in any store, and I would need the country you live in to help you with a link) but if you don't hesitate to have a different connector then the rest of the connectors on the board, you can use almost any 2 pin 2,54mm connector available on the market. In addition you need the MosFET 'PSMN7R0-30YL' This MosFET has to be soldered onto the board at position 'Q6' (Q6 is printed on the Wanhao Duplicator 4[x] Board). The last picture of this thing over here shows my Wanhao Duplicator 4 MightyBoard with the soldered in parts and 2 arrows pointing at them. I don't have a video showing me soldering in this two parts, but it's very easy for people used to solder SMD parts. Compared to soldering most of the normal SMD parts, this MosFET requires low experience. But it's your decision if your soldering skills are good enough and you can take the risk killing your board! Don't hesitate to record a video and I will share it over here, if you think it's helpful for other users over here.

Congratulations you are the first having this experience!
Never saw someone asking for help with less information on his comment. How should anybody help you here?
How is your setup and could you be even more precise describing you problem?

thruit00, can you advise please - does it fit Malyan M180, which is copy of Makerbot Replicator dual?
Many thanks!

Unfortunately not. It's not a 100% clone of a replicator 1.
I don't have this printer to test but as it is not having the cut out window in the middle of the rod it will not fit.

Thanks for reply! Can you place here the model, which can be corrected (to make the vertion without cut out in the middle of the rod) or maybe you can correct it to make your duct universal? Thanks in advance!

You will not like my answer, but I don't provide any source models. The reason for this is a contract I signed and have to accept. Sorry!

signed a contract with who?

So maybe you can correct it by yourself? It will do you duct suitable for lots of other printers...

Creating a duct like this took me about 100 Demo prints to make it fit perfectly and to get the maximum performance out of the little head room you have. I can't do this for a printer I don't have sitting on my desk. What about all the other cooling ducts already available on thingiverse for exactly this printer?

On;y one other cooler is avalilable. It doesn't cool in effective because has the flow in the front side only. Moreover it has two fans and is quite a big... The only thing which need to be done - is to take off this obtrusive part of the duct in front of it to fit the middle of the rod...

Love the design! Excellent work! Do you have a single extruder design, I have not seen a remix yet. I can try to make one on my own, but I would rather not re-invent the wheel. :)
Thanks again!!!

To develop a duct with maximum air output for the space available you need to have a printer to test the duct. I don't have any Replicator 1 or clone with a single extruder. So unfortunately my answer is no :-(

I printed this on a Flashforge creator pro and it came out fantastic......but my fan does not fit. I have a 40x40x10 fan but the opening on the duct is about 37x37. Is this common of do I have some issue with the printer?

Typically, it happens when a FF dual or pro is getting a Replicator 1 gcode inseated of replicator 2, everything shrinks a bit.

If it would be a problem of my model you would not see all those pictures of made things with fan installed. I would expect the same problem if you print a testing cube with the same slicer profile. Normal its a configuration problem in your slicer. rarely it's a configuration inside the printer firmware.
Sorry that I can't provide better support without knowing the slicer you use and the firmware you've installed (Does creator pro come with Sailfish Firmware preinstalled because of its ATmega2560?) Witch slicer are you using? Did you update slicer or firmware since you printed perfectly sized objects the last time?

I initially printed it using the astro print cloud slicer. I also use simplify3d and printed a 5mm calibration cube just fine so I have sliced it with simplify3d and am printing again.

I can confirm that slicing it with simplify3d solved my problem, fan now fits.

Great to hear!

I printed mine on a Flashforge Creator Pro and the standard 40mm fan fits perfectly, best check your settings I would say.
Hope it goes well for you.

Are there settings in MakerBot Desktop to control this new fan?

Never uses MakerBot (R) Desktop but even the antecessor MakerBot (R) Makerware (R) supported this feature. Currently I'm using Simplify3D witch is way better than all the other slicers I tested before. But anyways every good slicer should be able to handle the fan commands. As a rudimentary work around you could just update your start and end code, but good slicers even allow you to start fan at a predefined layer and leave it of while printing the first few layers to achieve better build plate binding and avoid warping.

Thank's a ton for the design, finally got mine all set up. I had a fan and the motherboard was all set up and ready for it, but I did not have a Terminal Block 2POS 5.08mm connecter. Ended up ordering a pack of 20 online, only used 1 of them, so if anyone run's into the same problem shoot me a message, I have plenty of spares.

Aug 1, 2015 - Modified Aug 1, 2015

I successfully printed (doesnt look the best) with no extra cooling fan on a Power Spec 3D Pro. I then installed the extra fan as my MB already had the Q6 fet and terminal block. I use Simplify3D to slice and it has the proper commands in the default start/end gcode scripts to operate the extra fan automatically. Can also test the fan using Replicator G and the M126 (start) and M127 (stop) commands. Surprisingly didn't need any screws to mount (everything was snug). When i reprint at higher quality this might become an issue.
-Fan: 40mm 24V 414F (Digikey PN:381-1082-ND)
-Male connector to mightboard: Terminal Block 2POS 5.08mm (Digikey PN: 277-1011-ND)
-used 5 feet of 20AWG cable (a little long) and crimped it to the fan

Hi there,

ive printed your fan duct for my CTC and the design for the installation is brilliant.
but ive a little question about the efficiency. i installed a screwed heat barrier so my nozzles are a few millimeters lower than the originals.
and the holes of the vents are kinda small. i blocked the left vent in the file by adding a wall on the left, because i only use the right nozzle for printing. but i cant feel much air coming out of the vent holes and cooling the nozzle or the print surface. i looks like the fan pushing the air inside the fan duct and reverse the air stream out again instead of following the vent way to the nozzle :-/

where I can find that chip that you mark on the motherboard? because my 3d printer don0t have anything there

There are a lot of working connectors out on the market but as long as they have a pin grit of about 5mm (some name it 5mm some 5.08mm) every thing is fine. For more details I would need to know the country you live in. E.g. if you live in Japan it makes no sense to link German stores.
Are you sure you only miss the connector, which is easy to solder and have an already soldered MosFET at position Q6?

I'm not sure if I missed it, but I read all the instructions and comments and didn't see and answer. What size and type of fan do I use on this?

Jun 1, 2015 - Modified Jun 1, 2015
thruit00 - in reply to drbohlen

See 'Thing Info' -> 'Requirements':
1x 40x40x10mm fan with 24V if you want to use the normal power supply as source

I personally use 'Papst 414F' on all of my printers for cooling the stepers, the stepper drivers at the mighty board and using them at the active cooling ducts.. I use them even though they are not cheep because they don't die after a few weeks and have a fairly good flow rate.

I second your choice in fans. I bought a no-name 24V fan from a supplier on Amazon. It died shortly thereafter. The Papst fans, while relatively expensive, are good investments in your hardware.

Thanks.. I guess I missed that.

Thank you so much for this design. I've printed it in ABS and it came out just about perfect. One question though - when my printer is printing (the brass nozzle is extruding on the build plate) how much space should the air duct be above the build plate? it seems the air duct is currently pointing at the middle of the brass nozzle and I'm thinking it needs to be pointing lower towards the tips.

The air leaves the duct angular and not parallel to the duct bottom so it is designed to point the air to the tip of the nozzle if you have normal MK8 or MK9 nozzles and used this nozzles calibration tool http://www.thingiverse.com/thing:299331 to calibrate your nozzles. I have only printers with MK8/MK9 nozzles and none with a MK10 nozzle, so I can't optimize the duct for this kind of nozzles and hotends!

Wanhao Nozzle Gauge Tool
by Raggen7

i have printed the duct and it is not pushing enough air out and i would like to modify it can you please post the file so i can edit it.(.stp .step .prt any a few more) my software will except a few other files too can you please post one of the ones i listed and if u cant can you post whatever file you can so i can edit it. thanks for your time and sorry to bother you.

I will not post other files than the stl files. I had this discussion several times but I will not change my mind. I share the suff I made for myself and which is perfectly working for me. I try to support others to get the same good results like I do. This duct is ment for closed cabin printing of ABS. It works for me with PLA, too, which was nerver the focus for it. Before I drew the first version of it, I had no idea how to design with a CAD tool. I had the chance to use a PC with a solid works licence on it and it took me one evening to learn it good enough to draw this duct. I learnd it the hard way that drawing is not the time killer. You lose the time when you optimize your model, Version 1 was released after half a year optimization with about 100 alpha and beta prints of it. Version 2 took one more month of my spare time with about 30 more prints and test installations on about 7 diferent printers.

What software did you use to make this freakin'amazing work?

solid works

I built one using ABS and it looked and worked great when I used it to print PLA. The first time I printed ABS afer installing it though, I didn't turn the extra fan on because I didn't think I'd need it. I was using ABS and only printing a few small parts. I walked away after starting the print and when I came back an hour and a half later, the build plate was clean and there was a huge ball of ABS fused to the new duct. The only thing I can figure is that the duct warmed and drooped a bit then caught a piece of the part being printed. Mayhem ensued.

Anyone else seen this? I should mention here that the duct was installed on an MK10 extruder in a Duplicator 4S. I'm wondering if I will have to run the new fan on all prints now, to avoid this issue.

I'm switching the fan on at layer 5 at all of my abs slicing profiles and using the same duct since end of october last year. I had the problem you described maybe twice inbetween. In my case it was related to a first layer binding problem to the build platform , so I had to calibrate my build platform or correct the temperatures of it or the extruder matching the filament I installed. In my case I was a lucky boy and could remove the filament ball at the duct outlets without harming the duct. But I have never tried my duct on a MK10 nozzles/heat block and can't say if this might cause the problem for you!

Can you share a STEP or IGES file please? I have made an adapter that allows you to connect to a blower fan, but I need to make some modifications to this design to allow for the higher CFM.


Can this be used for printing ABS? Will the parts warp?

If you closed your printer cabine (install arylic doors and a top cover), have a real flat and calibrated printbed covered with a good build plate (see my hints concerning the FR-4 plate) you can print abs with cooling fan switched on after the first layer without warping problems.

On 95% of my prints on all of my 3 printers I use ABS filament to print. For all of this ABS prints I use this active cooling duct with fans switched on at layer 5.

The question is not about this duct its more about your print plate and print camber.

For ABS prints you need a fully closes print chamber, a perfectly flat and leveled buildplate which can be heated to at least 100°C, and good adhesion on your print bed. Yes, none of the mentioned points in my last sentence is optional!
Instead of wasting your time with Blue tape, Kapton tape, glue sticks, hair spray or even worse acetone-abs solution you should invest in a GOOD print bed cover which you clip on you heated aluminum build plate. Go buy a FR-4 fiber plate 1-2mm think. (Personal advice: buy a white on, which looks good and you can see all leftovers on it). Yes, same material used for PCBs. You might buy two of them. One you sand with grit 400 sand paper and the other one you sand with grit 80 sand paper. Clean the once with alcohol and never apply acetone on them. Now you have perfect buildplates where you can print ~haft a year all day long on them without having to resand them.
The one you sanded with grit 400 is perfect for all of you normal prints. The other one for prints which are very high and/or have only a small area attached to the print bed.

What makes FR-4 plates the perfect material?
They have very strong adhesion while being warm and automatically detach from the model when buildplate cools down after print. This is because of a strong longitudinal extension of this material. The plate gets wider while heat bed heats up. Stays like it is while you print and keep the print bed temperature and after print is done and you cool down your print bed the FR-4 plate shrinks that much, that internal forces crack the plate from the model. Sounds strange but works perfectly.

With this kind of build plate and a good drive block (like my spring loaded drive block you can donload and print from here) I advice you to configure your nozzle to buildplate distance on the first layer to (0.3*Layer height). As I always do 0.1mm layer height prints this 0.03mm nozzles to build plate distance is much less than the typically advised paper thinness calibration. A fine feeler gauge might be a helpful tool.

To not have to recalibrate you print bed all the time another very good upgrade is a Z-arm support , like available very cheap on ebay. Google for ‘Home Zillions Platform stiffener Hanger’. They eliminate the major problem of sagging ABS Z-axis arms in heated build chambers. Thise upgrade is only required for the common ABS arms and not for the steal arms in FlashForge Creator Pro or Wanhao Duplicator 4S!
Hope this answer helps a little for losing the fear of ABS printing and warping!

Kind regards,

For a second there, I thought the shroud itself was liquid cooled. Those screw holes looked like ports. I may have to mod it to do that now lol.

Excellent mod. Nice improvement.

Apr 7, 2015 - Modified Apr 7, 2015

As I said in my comment before this is an amazing design however there is one major improvement I would highly recommend. After dumpster diving in the electronics recycling bin at work I found a great 24V blower fan that would be perfect. I then found out Flash Forge sells this same fan for a PLA cooling fan on their web site with a kit to mount it and a blower assembly. The thing is I like your design FAR more but the flash forge version has a vastly superior blower fan. I wish I were better at designing, I would love to be able to integrate this blower fan but its not so simple because the air comes out of that little side rectangular opening of a blower fan.

Here is a very similar fan to what I found. These move a ton of air.


I also considered using an radial fan instead of an axial but to be able to close the front doors it requires a flat fan and it has to be mounted in an upright position. Also the hight and witdh is a problem. If you install my current construction (v1 or v2) on your extruder carriage and move it to the front, left corner you will see, that the case frame limits the size of the fan block.Because of the upright installation you would also have to redirect the air by 90°. This redirection cost additional height we don't have.

This picture is not perfect for this purpose - it was part of the picture series I uploaded to thingiverse for version v1 of the duct, but it helps a little to understand the problem if you are currently not next to your printer:

Kind regards,

If a nice design could be made for a fan like this it would be incredible, imagine the overhangs you could do!

May 1, 2015 - Modified May 1, 2015

i've done this, and yes it is an incredible amount of air, i will post my mod soon

edit: check it out http://www.thingiverse.com/thing:802781

MEGAMOUTH COOLING FAN for Replicator 1 / Duplicator 4 / FlashForge / CTC / Monoprice! (REMIXED from Active Cooling Fan V2 by thruit00!)
Mar 28, 2015 - Modified Mar 28, 2015

Wow, I an finally print with PLA without running into huge problems from warping, drooping (and the nozzle then eventually knocking the part off the bed and coming back to the printer with a spaghetti surprise melted all over my extruder :(

I just printed this in ABS, got a 24V 40mm fan, the correct hardware and its running amazing. Parts I could not print 2 days ago are coming out beautiful. Luckily my Flashforge had the fan control available so I can even control fan speed and change it on any layer or turn on only for bridging etc.

I had to use my files to do a bit of clean up on the part, shaving down the hex things that the clips join with etc but overall I am very happy esp given a part this complex it fits excellent. Once I gave up on using dissolvable Stratasys SR30 support material it came out great. Not that SR30 doesn't work its just I don't have my dual extruder prints tuned that well in Simplify3D yet.

Thank you so much for this excellent design. You are a huge benefit to the 3d printing community. Hopefully I improve my modeling skills, only if I had become a mechanical engineer instead of electrical I might be able to contribute but I am trying to learn.

Thanks for the warm words! I'm only a software engeneer working as an architect and designing financial software for a big automobile manufacturer. So I'm as far or close to the mechanical engineer as you are :-) My motto is always: You can do everything after reading the internet - the only limiting factor is time!

Would you be willing or able to post the original file? Like in whatever software/format it was modeled in? I would love to edit this thing. What I would like to do: turn it into a dual-fan cooling duct - having either both the fans on one side or (and this is the more preferable option) have the fans on either side of the extruders (one fan on the front and one on the back).

Looking forward to your response.

It would be really cool if someone adapted this to fit on the back instead of the front of the carriage. Would allow better visibility.

ok i finaly have this up and running, thanks for the advise, but i do have a last question for it, is it just me or is the air flow a little restricted with this? im fanding half of the air is coming back out the fan instead of the nossels, (no i dont have the ran reversed lol)?

If you happen to have a powerspec 3d pro instead of a flashforge (powerspec is the clone), it already has the mosfet. Although I've noticed there are small changes in manufacturing every once in a while and this may be new, so still check before you connect the fan.

I have a Powerspec and there's something soldered on to the "extra" fan spot, but it's like there's a piece missing, there's nowhere to attach the wires. could you get a picture of how your's in connected?

NVM, another user actually mentioned this in a somewhat unrelated just shortly after I posted this. What we have soldered on is a terminal block, 2 pin. I need a terminal screw block, 2 pin, to be able to attach the wires.

Yes its a joke they didn't include the terminal block. I thinkn this is what you need. http://www.uctronics.com/10pcs-2edg-2pin-screw-terminal-block-connector-pluggable-381mm-pitch-right-angle-p-1870.html

I just found some of the correct female pins from work, borrowed their $700 crimping tool (insane for a hand tool) and covered most of the pins in heat shrink since I didn't have the connector body. So I just have pins with wires dangling but they are the perfect size pins. It works great. You could solder to these pins. I will try to look up their digikey part number tomorrow at work if you want. Its a much cheaper way to go, buy a few pins and some heat shrink and just solder or use a needle nose to crimp them. Heck if you want to send me a few dollars paypal I could crimp some onto to some red/black wire and mail it to you.

On the powerspec I already have the terminal block, I'm just missing the screw block. It cost $5 for 10 on Amazon with free 2 day shipping so bought some of those, should arrive tomorrow.

my wanhao duplicator 4S already has the mosfet on the board but noth the power connector, i can solder this on but do you guys know exactly the one i need?

Mar 20, 2015 - Modified Mar 20, 2015
thruit00 - in reply to Falcon1986

Where do you life? The connector are pretty common and every good electronic parts dealer should have them in stock. In Germany I buy them at 'Reichelt'. The connectors are called 'AKL 349-02' and sockets are called 'AKL 330-02' over there. An other online store in Germany named 'Conrad' sells them with the following part numbers 'D29483' and 'D29408'. Anyways because German stores might not be perfect for you please look them up visually at your prefered supplier and make sure you buy the right ones for a grid dimension of 5mm (pin to pin distance), because they are available for different grid dimensions. The connectors are rated for a maximum current of 12A.

also is there any information you could give me how to set my wanhao duplicator 4s up after i insall the fan, im not sure what this Gcode is or if i need to do anything for it to work, or if it will just start working after installing it, would be much appresiated

I'm using Simplify3d as slicer and here you can definde exactely when the fan should be powered on and of. E.g. lets say power it on on the 7th layer and always if it's printing bridges or small layers (even if this is the case on a layer numers lower than 7). But even if you have not bought this excelent slicer the fan is controlled in makerware, too. I never used the default profiles in here, but I think it's enabled for PLA profiles and disabled for ABS. If you switch to advanced mode you can set the property on your own, which tells makeware to enable or disable the fan, even if you are printing ABS. I do use the fan on all of my ABS prints. If you have warping problems on ABS with fan switched on, you should buy a good long term print plate (I suggest to buy a white glass fibre reinforced plastic (type FR4) 1mm think plate on ebay and sand it with a 100 grading and clean it with alcohol [NO ACETONE] afterwards). On this kind of plate prints say attached to the plate if it's warm and automatically detach after cooling down. I think other slicers can control the fan, too. I just have not tried :-)

England :) I do have a store would have them called Maplin but I found some I think are ok on ebay for next to nothing

OMG!!!! terminal screw block... This is what I've been trying to find for about two weeks now! THANK YOU!!!

Your welcome lol

where do you get the FR-4 fiber board from? does it not have copper clad on it? i saw you talking about this board.. is it just something i clip on the heated bed after i sand it and i print only on that? no tape no glue? is it reuseable? also i have a ctc dual and my firmware is 1.0 any recommendations on if i should change it and what to? i use meshmixer and makerware.. i was gonna get simplify as i had it before when i had a makerbot and i sold it with my printer..

if you use a copper coated FR-4 pcb you mighty need to get rid of the copper by using iron-3-chloride or fine-etching-chrystal. It might also work without removing the copper and keeping it on the bottom side as a second heat spreader printing on the sanded FR-4 fibre board, but I have not tried, jet. In Germany FR-4 boards are available on ebay without copper coating in several colors: E.g. over here: http://m.ebay.de/itm/151692908860

Just an FYI, this will hit the heater blocks on the Wanhao MK10 nozzles and end up melting part of the shroud like on Dogm's picture. I have not connected my fan to my printer to test it yet so I'm not sure how much this effects the performance but it looks like just a minor inconvenience so far.

I have not made this duct yet but in preparation for doing so I printed the pre-cursor that is recommended in the instructions (PLA Replicator Ducted Fan Clips Modded). It actually works pretty well for me so I am going to try and make this duct in the near future. Frankly, my urgency has gone down a little given how well the precursor works! Thanks for the recommendation!

wisar - in reply to wisar

Finally got this duct using a 3D Hubs printer and was then able to print one of my own. This thing is a work of art. I did not really need a second one but I wanted to see how it would print. It really is pretty! Works as well as it looks though it will make leveling my print bed a little more cumbersome.

Mar 10, 2015 - Modified Mar 10, 2015

Hi, can you public source with solid models?
This is almost amaising thing, but my printer need both front and rear fans and some different distances with nozzles...

Mine did the same thing. I just snapped off the melted pieced and pressed on. All things considered, it's still a great design.

Works great! Thanks for the neat design!

The only problem i had with this is the clips were a little too wide on their tab that fits into the slot on the carriage. I filed a little off the end and a little off the inside edge until it was the right thickness to fit into the slot on the carriage yet snug so it was nice and tight once the 3mm cap screws were tightened down.

I haven't built a way to turn the fan on and off yet, still a work in progress, i mainly made one of these to give it a shot on a part i have been working to make that had some overhangs and i was getting a decent print but with a little sag and stringing on a few small openings. Printed one of these without any active cooling and it turned out really good except the very top where it goes across the top edge of the fan, but i just cut that portion out as i would have had to anyway since the fan i had in the junk drawer has its wires coming out from the back with no slot to route them around to the front so it worked out anyway.

I print all ABS, i don't print anything PLA, and this has really made a difference on a few small finnicky parts. I plan on just adding a switch to the front of the printer to turn this active cooling fan on and off as i need to, as i don't run sailfish and never plan to, tried it once it was just too buggy and too many issues to overcome.

Thanks again!

Hey! Did you ever add a switch to the front of your printer? I am a little puzzled on what i need to do so. Could you recommend a switch i could buy?

This needs more air flow i feel the air coming back out of the fan on cooling duct. anything you can do about this like the design.

should i print this with or without supports?

Also would this work with wanaso d4S with mk10 nossels?

Recomend you make the right side flat so it can hit the stop sensor. I had to sand it down.;

I JUST printed this for my FF Creator Pro and installed it without a hitch.. Actually no screws either... Its tight enough fit to go on without screws so I can more easily remove it.
First PLA part I tested printed very well and cooled easily. The way the vents wrap around the back side give it good coverage from almost all angles.
Couldnt be happier with this shroud. WELL DONE>

Feb 22, 2015 - Modified Feb 22, 2015

This is a work of art and works well. Perhaps too well. I think my duct is cooling the nozzles so much that the printer struggles to maintain temperate when the fan is on.

I may need to raise the nozzles? Please can you tell me how low the nozzles should be compared with the bottom of the duct?

(CTC Replicator Dual)

Feb 23, 2015 - Modified Feb 23, 2015
thruit00 - in reply to notdave

I recommend this simple tool to calibrate the nozzles:

Wanhao Nozzle Gauge Tool
by Raggen7

To wide for the Creator Pro. Hitting the stepper motor before the stop switch. Could you put out an editable file or make one for the pro?

I have other users using this duct on a creator pro without mentioning problems. From time to time I have a users whose printer is not stopping at the Y axis switch because of this duct - independent of the replicator clone model they use. Did you read the comment of 'Weeves' and my answer over here? Is the problem really that big that bending the microswitch spring steel is not solving the problem?

This comment has been deleted.

is it possible to creat a longer Version to mount on the backside,
i have an ctc an conect the wires on board "Fan CS" too, now the Fan is curently work.
Thank you for this perfekt Disign.
Regards from Germany

is it possible to creat a longer Version to mount on the backside,
i have an ctc an conect the wires on board "Fan CS" too, now the Fan is curently work.
Thank you for this perfekt Disign.
Regards from Germany

See 'Remixes' over here - there you will find a version to mount at the back of the extruder rod developed by CyberMosFet. I can't test or develop a version cause I have absolutely no space left for it at the back of all of my printers. I use the brilliant an fair priced 'Home Zillions Platform Hanger' upgrade to fix the faulty design of using ABS Z axis arms. After this upgrade I only have recalibrate my buildplatform once every 6 months. Before I had to recalibrate it for every print.
Greatings back from Stuttgart, Germany.

Great job!
Ran into a small problem on my Duplicator 4x: the RHS of the duct hits the stepper motor before the x-axis endstop activated. Small bend in the x-axis microswitch arm & all good!
I installed the MOSFET at the same time - so board controlled cooling - Yay

It's a pretty tight construction on all of my 3 printers where I designed if for and tested it on. Unfortunately the manufacturing tolerance of the printers sometimes requires to persuade the switch to detect the rod by bending it like you did.

This thing is a beauty.
Printed the duct as my second print ever on the flashforge,
0.1 mm layer with ABS with feedrate and travelrate at 30, the finnish is amazing, and had no problems with any of the overhangs.
Actually had more problems with the clips.
I can't wait until my fans arrive in the mail for connecting it properly up.
Thanks mate.

Thank you so much! This is the best for Flashforge !!! :)

What would happen if, instead of adding a new fan, I took the left extruder fan off and moved it down to use for this duct?

I feel like soldering wires is a little beyond my skill level.

This would be a very bad idea! The aluminum bar spreads heat from one hot end to both steppers as well and that's why after a while printing with one nozzle even the second fan on the other mot in use nozzles side jumps in to protect the inactive stepper from overheating. On the other hand the fan at the cooling duct has to be switched on almost for the whole print except for the first few layers. So if you are no soldering expert, install a third 24V fan at the duct, longer the cable any way you are capable of (if you cant solder at all use luster terminals), install the cable next to the other cables down to the bottom of the printer and connect the plus pole ito the 24V rail and the minus pole to ground at power supply. If 3rd fan spins after you switch on the printer, switch it back off and install a switch in between the 24V plus cable at the bottom of the printer to be able to control the fan manually.

Or you can buy fans that are USB powered, which you can easily power using an external power supply, and unplug when you don't need it (e.g. printing ABS). Not as nice as controlled by the motherboard, but dead simple.

Thank you. Unfortunately, I think this little project is more than I can handle. Things like "install a switch" are not things I know how to do.

It looks like a great add-on. Thanks for responding so quickly and helping me understand.

For the manual switch I tried to guide you to you only need very, very basic electronic knowledge. You do not have any family member, neighbor of fried who is capable of doing this for you?

Okay, here's another crazy idea.

Would it be possible to just wire the fan into a plug? I'd run the wire down the back like normal, but when I wanted to start the fan, I'd just plug it into my power strip.

You could buy a STRONG 40x40x10mm fan and a wall power supply for the same voltage as the fan is designed for (e.g. 24V or 12V depending on you fan) and use the power supply cable all along the way from the bottom to the 3rd extruder fan. Their you can connect (e.g. with luster terminals) the fan cable to the power supply cable. And yes, than you can just plug in and out the power supply when you what the fan to blow.

Okay, I looked around a little. Would these items work?

Fan: http://item.taobao.com/item.htm?spm=a230r.1.14.118.BpYClp&id=41863653561&ns=1&abbucket=12#detail

Luster Terminal #1: http://item.taobao.com/item.htm?spm=a230r.1.14.1.QpYb0l&id=19414721295&ns=1&abbucket=12#detail

Luster Terminal #2: http://item.taobao.com/item.htm?spm=a230r.1.14.6.QpYb0l&id=20438711809&ns=1&abbucket=12#detail

Wall Power Supply: http://item.taobao.com/item.htm?spm=a230r.1.14.61.jtbgIi&id=42679711803&ns=1&abbucket=12#detail

I think I'd have to strip the wire off the power supply to hook it to the luster terminal. Is that correct? I guess I'd need the second terminal I linked to for that.

It's too bad there isn't an adapter for the power cable and the fan cable.

Jan 5, 2015 - Modified Jan 5, 2015
thruit00 - in reply to JasonMBryant

The PAPST 414F is a good choice and a very cheep offer. The power supply would also work perfectly but is very expensive for the Chinese market. The luster terminals you linked make no sense. The first has a white connector you don't have and the second one you have to solder. If you can solder you don't need any luster terminals and only need something to isolate the open open wires. A perfect and solder free solution would be this one:
On the second picture the lower adapter helps you to connect the power supply you linked without cutting the original connector and use the luster terminal on the other side to connect the fan by only screwing the screws.

Great, I think this will work. I've already printed out the duct. It's actually the neatest thing I've printed. I'll let you know how it goes.

Great to hear! Keep my fingers crossed for your project and look forward to your updates.

I got it working!

It's definitely an improvement. It's not as amazingly better as i had hoped, but I'm definitely seeing an improvement. I forgot to turn the fan on one time and got to compare with and without side by side. With the fan looked much better.

I tried another model of fan, one that mounts in the back. The results were not as good. That might be because the design just blew the air in one direction, instead of surrounding the nozzle like yours does. I've had to remove the duct twice already to get to jams, so I'd still love one with your design that mounts on the back, but this will do for now.

Because I use the 'Home Zillions Platform Hanger' on all of my 3 printers (to not have to recalibrate my printers all the time) I have no room for a back mounted fan construction. So I will not design a version which I can't even test. I already have back preasure problems on my front duct, which would get worse because on most Replicator 1 clones you have much less space in the back - even if you avoid a construction like the home zillions platform hangers.

That's interesting. Thanks for the insight. I'll keep that in mind before trying to design my own.

Thanks again for all your help. The duct works great and the advice on how to set it up was awesome.

I've got all the parts ordered and the duct printed. I should have the parts within a couple of days. I have a couple of questions.

1) The fan and the power supply are both 24V, but the terminal is only 12V. I looked, but I couldn't find a 24V version of the same thing on Taobao. Does that matter?

2) I attached the duct to the printer and realized that it will have one drawback. I'll have to take it off every time my printer jams. It jams about half the time I unload the filament, which means I have to take off one of the fans and pull out the excess bits of filament. I've tried to find a solution on the internet, but no luck so far. Would it be hard to come up with a fan duct that attaches to the back of the extruder instead of the front? Then I wouldn't have to take off the duct when my printer jams. It looks like it would be the same design, just about 15 cm longer on the bottom.

I'm currently living in China. So yes, I do have family members who could help, but they are several thousand miles away. :)

best mod ever to any FF printers! thanks for your awesome work

will there be a version with m3x60 screw holes like in v1 please ? :)

Unfortunately not. People having problems getting the M3x60 screws drove me to this new design. In addition the original M3x60 screws are to annoying to remove if you want to clean your drive block.
Sorry for the bad news!

I will never print without it again!!!! 200% better prints. Really notice it on small objects that would get to hot and warp without it. Only draw back is that its hard to watch it print in the begininng. Love it

I have tried many versions of fans for my Duplicator 4X and this is by far the best out there, the fan does not intefere with the the front door which is a major bonus. I sliced mine on S3D and printed with only support for the square fan housing section and it came out perfect.... many thanks for sharing.

Thanks for the kind friendly words! Even the part above the fan can be printed without support if you have active cooling. So now you can print them as christmas presents for all of your friends without support :-) Even though you never expect, you will be supresed how good it works! All of my ~40 prints of this duct while developing it (e.g. the yellow ones from the pictures) are sliced with S3D and printed without support. I took the pictures directly after tanking them out of the printer without any rework.

Happy printing!

Nov 19, 2014 - Modified Nov 19, 2014

Have you reduced the number of baffles/airguides ?
I'm using the original duct with an add on adaptor. And it really makes a HUGE difference.
Printed at 0.2layer height with no issues.

many thanks for the design.

My only issue is that air flow is restricted by the number of channels. I've got a cheap 24volt 4cm fan and I still get quite lot of back pressure airflow. ie I can feel air coming out the back of the fan as it can't all go into the duct.

I'll try the new duct and see if it's any better.
Cheers :-)

Back pressure should be reduced on the new version a little. I cleaned up the inner roof construction of the channels to gain the cross-sectional area. In addition I redesined the air redirection to provide more air for the outer channels and the surrounding fan walls should reduce the air loss at the connection between the fan and the duct. But anyways don't expect too much, it's still a very sharp corner where the air has to pass by. One of the major goals of this duct still is to allow to close the front door for ABS printing, which is limiting the space for this construction.


BTW: I'm installing the duct right now, and i'm wondering if it is normal, that the fan duct touches the nozzle?

No , it's not! See my pictures how it should look like!

Nov 14, 2014 - Modified Nov 14, 2014
thruit00 - in reply to thruit00

it touches your Nozzles or heat block? Distance to nozzles should be several millimeters distance of the middle air duct finger to the heat blocks should be about 1mm. This is enough to not burn the duct on my printers. How you calibrate your nozzles to the same height? Maybe you use a different tool and that's why they are installed in a lower position?

I use this one: http://www.thingiverse.com/thing:299331
Nozzle calibration is not the correct naming - I should call it thermal pipe calibration tool.

Wanhao Nozzle Gauge Tool
by Raggen7
Nov 14, 2014 - Modified Nov 14, 2014
OnkelPierre - in reply to thruit00

Sorry, not the nozzle, i mean the heat block. I can't install them higher. The thermal pipes are mounted on the highest possible point, just slightly below the extruder parts.

Okay, got it. I removed the nozzle and was able to screw the heat blocks 2 turns up. Now it's enough space between fan duct and heater block.

Nice! Printed today @ .2mm on my almost stock CTc without any issues. Not the nicest finish, but for a printer with open build area and without cooling for bridging i can live with that.

I'm surprised how good the bringing above fan is! Generally S3D is handling bringes very well, so it always tries to find the shortest way for the first bridge layer. At the part above the fan there is not much room for optimizing the bridge.

Because of Silplify3D, the aluminum hangers and the glass plate I would not call your printer "almost stock" :-)
Strong adhesion by blue tape, a perfectly flat build plate because of glass and your aluminum arm extensions help you to keep warping problems low even without a closed cabin.

Thanks for sharing your "Make"!

Nov 14, 2014 - Modified Nov 14, 2014
OnkelPierre - in reply to thruit00

I'm surprised too! The top part with the 40mm bridges is definitly the trickiest section of the part, but it worked okay. But i still don't get almost the superb Quality of your prints!!!
How do you know, i'm using S3D???

I can see the skirt surrounding you model ;-)

Wird bei der nächste Gelegenheit gedruckt! Nehme es sofort in unsere CTC-Tipps auf :)


I've been waiting for this. I'll be printing it tonight.

Brilliant with your new clip to attach it to the carriage.

You might want to give FlashForge a call as Make Magazine just issued their latest 3-D printer shootout and the Microcenter rebrand of the Creator Pro came out on the very bottom, due to the lowest scores on bridging and overhangs with PLA.

I know your cooler make a massive difference in my prints.

You are awesome to go to such great detail on your improvements.


Whats the link to this shootout with the results....ive looked everywhere

You've got to buy the magazine.