Loading
kommisar

Prusa MMU2 Spool Holder

by kommisar Dec 1, 2018
Download All Files

Thing Apps Enabled

Please Login to Comment

Thank you so much for sharing your amazing design and all the refinements. Would you be willing to upload the source or stp file for your tube connector block? Or would it be simple for you to generate one for an M10 fitting? (I have a bunch of those on hand from another project and would like to use them here. Thanks!

What's the benefit of this over a normal big spool holder?

If i'm reading this and looking at the pictures correctly, the only part in the assembly that isn't 3D printed is the bearings, right? I'm looking to get the parts I need and want to make sure I'm not missing any screws/nuts that aren't printed.

Hi Tdub415,

Indeed, bearings are only essential non-3D printed parts. Tube fittings are optional and design provides 3D printed option.

Best regards,
Alexander K.

First of all I wanted to say that these spool holders look amazing and should work great!
So I really want to make these to enhance the MMU experience.
Sorry to say but I'm unable to match some of your description with the files provided..

1 filament guide,  (FilamentGuide_Universal.stl) 
one of the guide tube connectors, (TubeConnector M5 or M6 or PTFE ? How do I decide which one I need?)
6 axis screws, or 5 axis and 1 with a guide, (again, how to decide?)
5 608 ball bearings,  (are these the one which came with the Prusa spool holder?)
1 of 5 number plugs.  (since there is no Plug.stl I assume StandNumber_1 -StandNumber_5 are the correct ones?)

I look forward to any advice to finally start printing these! (:

Hi AnTimoNie,

First of all thanks for the kind words!

Regarding your questions:

  • Tube connector selection depends on tube fitting you have. In case you don't, just use PTFE connector.
  • If you print from zero, use 5-1 configuration. 6-0 in case you already have an older version of the holder or reuse parts from parent thing.
  • Yes, are the same bearings. But because my design uses 5 per holder you need additional 5 to have 5 holders.
  • Yes, number plugs are named StandNumber_x.stl

Best regards,
Alexander K.

Thank you for helping me out.
Well as far as I know there weren't any spare bearings delivered with the MK3S but correct me if I'm wrong.
Anyways, 4 spool holders of yours will be better than 5 of the original Prusa ones!

I forgot to print the FilamentGuide_Universal but the rest is already assembled and in use for printing the last part!
The design is ingenuis and all parts fit perfectly and the whole project is easily put together with the supplied scheme.
I already love this design and you should pitch this to prusa, they should ship with your spool holders!

I can't seem to print the coilstand stl. It is too tall to print upright on my prusa i3 mk3 but when I lay it down, the printer can't handle the "over air" print of the arms which have the hex head on them.

How are you guys printing the coilstand? Is the prusa mk3 actually capable of printing this tall and I need to adjust a setting?

Thanks for the help!

Hi Nicholas,

You need to lay it flat and print with support. Slicer will generate small support islands under the screw recesses.

Best regards,
Alexander K.

This helped. Also, printing with a Brim prevented the longer pieces from lifting off the print bed.

Now I just need to figure out how you routed your filament such that what's happening in my photos attached does not happen. Any ideas?

I suspect that the PTFE tube, and the route the ink has to take to reach the extruder, might be to blame here. Any suggestions?

Hi Nicholas,

It looks like some kind of twist along the filament axis. Please follow the threading instruction I provided in the thing description. Start without connecting the output tube. Thread the filament, push-pull it to observe it goes correct path.

Best regards,
Alexander K.

Thanks again! Somehow my filament spool was not fluently wrapped. I had to take all the filament off the spool and rewind. Now it looks like your pictures and functions perfectly. Very happy with this design.

So I know this is for the Prusa MMU2, but it looks like a really well-designed spool holder, and I was wondering if there is anything about this build that would make it ineffective for using one on any other printer? I've got a CR-10 and have felt like I haven't found the perfect spool holder for my purposes yet, but this looks amazing and I'd love to give it a shot. I'd just hate to print it and find out after putting it together that it doesn't jive with my setup for some reason.

Hi Cthanatos,

As you mentioned this spool holder is for use with Prusa MMU2. It especially designed to accommodate filament retracted from the printer during filament change. If your printer doesn't do it - there is no point in using this specific spool holder.

Best regards,
Alexander K.

Comments deleted.

Great design. It appears that the tab on the bottom of the new FilamentGuide does not lineup with the holes on the bottom stand.

Comments deleted.

Hi Thomas,

It looks like your Coil Stand is mirrored. Probably during placement. The stands are not symmetrical following original design.

Best regards,
Alexander K.

Sorry my comment didn't post from my phone..

Thanks for pointing that out, i must have mirrored the part when i sliced it..

i was just going to ask you about a few issues, and it looks like you addressed them all in your jan update! I have MANY hours on these spool holders, and they work well, my only issue is that the filament occasionally jams between the filament guide and wheel as shown in the pic.

i will try the new filament guide out.

thanks for all the hard work!

Hi Jon,

Did you get a chance to try the guide of new design? In my case no jams so far.

Best regards,
Alexander K.

Hi,

Posted in the wrong spot before, so I moved my comment here.

Hi!,

Yes I have, I have run approx 3kg PLA,, 2 kg PETG, and a little ABS, no problems at all. The new outlet for the filament (to the bowden tube) is awesome!

The only thing I can say I have trouble with, and this is an extreme case is with specialty filaments like bronzefill., the filament is so dense, and rough that it binds against the side of the reel and back guide. I find that when i have to print this stuff I use the config shown in the picture. It uses 2 holders in series. This allows the denser filaments to unwind smoother.

overall, I am very happy. Working great!

Thanks for the update!

Especially for the cases there it is better to separate wheel assembly from the spool holder itself I designed standalone version of the Coil Stand: https://www.thingiverse.com/thing:3268851 This design includes skeletonized stand and some additional parts to assemble it.

Best regards,
Alexander K.

Standalone Filament Guide for Prusa MMU2

Just printed off and assembled 1st one. Printed and went together really well, including all the threaded bits. Just playing with it at the moment, since I'd chopped all the PTFE tubes, so waiting for some more to arrive.

Love it, looks more complicated/intimidating than it actually is. Don't fancy fixing it to a hard surface just yet, so made a couple of support legs by taking your stand and chopping everything 12mm from the bottom and extended the ends. It's pretty simple, but I'll post a pic/STL on here if it works well...

Additional units printing. Thanks for the great design.

Support legs make it more stable of course, but still slides around. Might try adding sticky feet.

Hi Zubzilla,

As far as I understand you would like to have the stands on some kind of hard surface like varnished wood. My suggestion is to use small rubber feet from hardware store. 3-4 to the rail and 2 on each stand.

Best regards,
Alexander K.

I finally print 5 stands ;) For my personal project i need to mount the 5 stands on cheap ikea table so i have to redesign the rail for fixing with m3 cup head screws ...not big deal ( https://www.thingiverse.com/thing:3400394 )

But for aesthetic issue i want to mount 2 stand in miroir position.
So i try to juste mirror the filament guide ...

but i juste notice ... wtf, why nothing is symmetric ? ^^

(PS :ho i break one screw again -_-", pla 100% seem not a good choices )

Prusa MMU2 Spool Holder Rail Remix M3 Cup Head Screw

Hi,

Indeed the stands are not symmetrical as per original design. But probably provide adjusted mirrored guide is really good idea. Stay tuned... ;)

Regarding the screws material, I print from PTEG/ABS with 100% infill. PTEG goes strong. ABS breaks but proven to be easy to repairer with acetone.

Best regards,
Alexander K.

I keep busting the stands trying to get the screws in. Any suggestions?

Hi,

Is it possible to share a photo of your prints (stand and screws)?
In general, there are two possible issues - screw oversizing due to over extrusion/over temperature and stand opening distortion because of squashed first layer.

Best regards,
Alexander K.

I think I found the issue. Trying another print.

Can you please share your finding?
It is really interesting to see the stand printed in upright position with surprisingly good result. I usually rotate it with flat side down and support for screw recesses. Also the filament blobs on your prints are a clue for some kind of extrusion issue.

Best regards,
Alexander K.

Just printed the first one in PETG, screws printed beautifully on the first try. Took me a few minutes to figure out how you were threading the filament through the entire device, but finally figured it out. Works like a charm!

Hi Cory,

Thanks for sharing your print! It looks awesome! Hope it will serve you well!

Best regards,
Alexander K.

Finished printing 3 for now, MMU won't show up for another week, so figure I'd get prepped for it. The last print was really tight (needed a hammer to get the spacers onto the screws) but it seems to be doing fine, just may have lost some tolerance printing all the parts in one batch, who knows. Once again, great work! I dry tested it by hand and it does exactly what you designed it to do.

Thanks Cory,

I had something similar with my screw and spacers because of squashed first layer. Pass with deburring tool fixed the problem.

Best regards,
Alexander K.

Do all parts need to printed in the original orientation of the file?

Hi BrianLeeRussell,

Small parts parts are oriented properly. Big parts you need to orient according to your printbed capabilities. Anyway, all the parts have flat side to be placed on the printbed. But both stands require support to print screw recesses.

Best regards,
Alexander K.

Sorry to ask so many questions, hopefully this will be the last. When we put the bearings inside the wheels, we can get them to sit flush, but there is still more room to push the bearings further. Hopefully the pictures will show what I’m talking about. Should we leave the bearings flush with the top, push them all the way to the bottom, or try to center them as much as possible? Thanks!

Hi Duane,

Push the bearings all the way down to the wheels bottom. Axis spacers will properly situate the wheels.

Best regards,
Alexander K.

Okay, I kind of semi-hijacked another persons thread regarding issues I was having making the screws and nuts.

Here is what worked for me, I hope it may help someone else. I am printing everything except the screws out of PETG. I print the screws with high quality (Hatchbox) ABS. The shrinkage of the ABS makes the screws come out to a perfect size. The reason I specify a high quality brand of ABS, is that when I used a cheaper brand, the screws broke off right where the threads start, with very little force.

I'd like to once again thank Alexander K for an ingenious design, and for being so willing to help out by being so responsive to questions. Great work sir!

Thanks a lot Duane! I really appreciate it!

Indeed filament/print quality is really important for such intricate shapes like threads.And there is always a trade off between tight fit and printing tolerances. And for me as designer, community feedback is really important to make thing more user friendly and easy to make. Again, thanks for your effort to troubleshot the printing issue and your feedback!

Best regards,
Alexander K.

Love this design too. i try to print my first stand ...
But always bad print on the screw and nuts ... bas thread at 0.2mm :/

Do you have some tips ?
( i retry to print at 0.1 with some change in my slicer )

Hi Teddy,

I print the holder parts from PTEG /ABS with 0.2mm layers, 10% infill for all small parts, 20% for the stands and 100 % for screws.
Do you have a picture of the failed print?

Best regards,
Alexander K.

0.2 or 0.1 mm is same result ... blob on the thread
I use black tianse PLA ...
i try to remake the threads with the nut, but need a lot of strength and the screw breaks in !

My neighbour lend me a kit for making threads on metal part :) with the kit i think can clean the plastique part without effort and break ;)

Ps: i already print M10 screw and nuts, but smaller its hard without post treatment...

Clean screw and nuts with this tools and is perfect ;)

but i'am too strong ^^ and i break a screw when i mounted the first one -_-"

For the moment i print the 4 other in pla ... but i think i'm going to buy some PETG or ABS and replace piece when they broke

( PS i includ a photo of the tools, i didn't find they real english name :/ )

Tap and die :) Really useful to make plastic parts true.

The resulting print look really nice! Hope it will serve you well.

Regarding the issue with the threads, probably you need to play with temperature and extrusion volume. Try to lower nozzle temperature or use one of the temperature calibration things (https://www.thingiverse.com/thing:2493504 for example). From my experience different filaments of the same type can produce totally different results. I use Prusa PTEG (not Prusament) with standard Prusa profile (230C nozzle temperature) and get really good results (see picture attached). But to print with Makerbot ABS I had to shrink the screw a little bit. And with generic ABC spent a lot of time fine-tuning temperature.

In my opinion PLA is totally Ok for the holder. The only concern are the screws. Just be gentle tightening the nuts.

Best regards,
Alexander K.

Temp Tower PLA,ABS,PETG

Alexander,
I posted a picture of the struggles I'm having similar to Teddy, but for some reason it was flagged for moderation. Hopefully it will post soon. What size are these screws and nuts, and what is the thread width? I'm thinking I might try to get an actual screw and nut, and run them through my printed ones to clean the threads out. Thanks again for all the time you spend helping us print your great design.

Hi Duane,

The thread is M8. The thread base diameter is slightly undersized for screws and slightly oversize for nuts. Probably in your and Teddy's case the best approach will be to enlarge the nuts in slicer by 1-3% on XY plane.Try the flat nut first. But to be sure I also suggest you to check the fit of the axis spacer and ball bearing with axis screw. If it too tight keep the nut as is and shrink the screw to get desired fit.

In general the design takes in account plastic parts tolerances to achieve tight fit but there are always some deviations. In some cases little tweaking in slicer is required.

Best regards,
Alexander K.

Sounds great, exactly what I was thinking as far as scaling the parts just a bit. Trying ABS, at .1mm, 100% infill right now on a different printer. I'm sure I'll get a perfect fit soon! I will post what ends up working the best for me, so that it may help others. Thanks!

Hi Alexander,
It’s really nice of you to post your design, but also to respond so quickly to help out as well. I’m having similar issues with the screw and nuts. When I print them at .2, it is like the screw is a bit larger than it should be, it barely fits inside the nut. When I print at .1, it helps make the screws fit better, but I have this stringing in the threads (see pic). I’m using PETG, and I know it tends to string a lot. I thought of trying ABS, but I find that it tends to shrink, which affects parts that are size critical. I haven’t gone above 30% infill, but would be willing to try 100% if that would help. I would also be willing to try ABS if you think that would help as well. Thanks again!

Hi Duane,

It looks like you PETG print suffers from excessive stringing. Is it possible to try and print the nut with lower temperature? In my case I use Prusa PETG and print it on 230C. This temperature is recommended by filament manufacturer and works really good for me.

Best regards,
Alexander K.

Love this design. I'm have a problem with filament getting suck between the large filament wheel and the filament guide. Has anyone else had this problem?

Hi Brad,

Can you please share a photo or video of such event? The gap between filament wheel and guide is really small by design and it will be interesting to see how it happens.

Thanks in advance,
Alexander K.

Thanks Brad,

It looks like in your case filament goes over the edge of the filament wheel and than stuck between guide and the wheel. The question is it it goes over the edge first and than in-between or in-between first and than over the edge?

The design relies on nature curvature of the filament and that curve pushes the filament up against the wheel. But to work properly, filament must go through PTFE tube inserted into exit hole. Straight section of PTFE tube formed by its connection to the guide prevents from filament to snap from the wheel.

Anyway I will design additional cap to close the existing gap between filament wheel and bottom part of the guide. Hope it will help.

Best regards,
Alexander K.

It goes over the edge of the wheel than get stuck in between the wheel and the guide. it seems that some of my filament gets a twist when pulled tight around they wheel. Then when the filament goes loose it flops out.

  • Posted with 3D Geeks Thingiverse Browser App

Got it!
I added small Anti Twist Bracket to be mounted on the Filament Guide. Please print it and attach to the Guide as it shown on the photo. Hope it will fix the issue you have. The bracket should prevent filament form snapping from the wheel even the filament itself going over the wheel edge.

I'm working on new version of the Filament Guide and if the bracket approach works I will incorporate it into new design.

Best regards,
Alexander K.

Where the new Anti Twist cap go, i don't see any new pics of it placement?

Hi Peter,

Please see attached photo. Sloped part of the bracket going under the wheel.

Best regards,
Alexander K.

Do you need to glue it in place?

No, just snap it over the guide as on the photo. Should be enough.

Best regards,
Alexander K.

What is the enlarged axis spacer? Should we print one at a higher scale? And if so, how much. Also, thanks for what looks to be a great design!

Hi Duane,

https://www.thingiverse.com/download:5841506. I renamed it to be consistent with the description. You need only one like this. Please see the exploded diagram for the spacer location - back arm of the Coil Stand.

Thanks and best regards,
Alexander K.

Seems to work much better than the stock system and takes up a whole lot less space. Nice work!

Great design and mostly solves the MMU2 and Lack enclosure issue with the MMU2.
My enclosure is against the wall and I was wondering if there would be any way for the filament to exit through the bottom, if not perpendicular, then at a close angle to perpendicular. This would eliminate the space needed for the radial curve from the holder to down the back of the enclosure.

is there a reason it's so tall? that upright seems uselessly tall... I understand it helps constrain the loops but they don't ever seem to get that high and it's adding unneeded height to the whole thing. am I missing something?

I want to make a more low profile version of this so I'm hoping to chop some off the top and bottom of the design.

Hi Nathan,

It takes up to 160mm out of 200mm available space (or 80%) in case normal, close in size, loops are formed. In some rear cases one loop can be bigger and take up to 90%+. Also, the total hight takes in account possible elongation of the bowden tube.

Original design included additional 20mm to the hight and you can still see it on the pictures - stand with blue filament wheels. Rest of my stands are final design.

Best regards,
Alexander K.

If I pass the filament from the spool into the hole of filament guide then the filament is jammed into the hole.

Hi sdalee,

It is highly unlikely filament is jammed in the hole itself. The hole diameter is 4mm, way above 1.75mm of the filament. But you need to thread it above the opposite side of the guide and up to the wheel. This difference in hight between the entrance hole and opposite side of the guide is by design and required to avoid filament unwinding from spool while unloading filament from the printer. I usually slightly bend up the filament end to clear the guide.

Best regards,
Alexander K.

I think I did not write it down clearly. The hole is perfect and clear.
I threaded the filament on the hole and twisted it twice on the filament wheel 608. After that I started to pull it. Some time later (I pulled about 20-30 cm) jammed the filament. Until this point it came easily.
After that I pulled the filament out of the hole and just twisted the wheel twice, and the filament came nicely.

Hi sdalee,

Sounds like a crossing between loops on the filament wheel.

Best regards,
Alexander K.

It's a fantastic construcion and I have already printed it in a copy.

But I have two questions. (I ordered the MMU2, but I will get it in february 2019.)

  1. Isn't small the diameter of filament wheel 608 If I use more rigid filament. Doesn't the rigid filament brake?

2, I would like to build an enclosure to MK3 printer, MMU2 and 5 pcs filament holders from IKEA Lack table and I'd like to place the filament holders under the MK3 printer. Can I do it? Will not be too much distance between the MMU2 and the holders if the filament holders are under the printer?

Hi sdalee,

Thanks! Will be glad to see your copy of the holder.

Regarding the questions:

  1. Filament wheel effective diameter is 60+ mm - gentle curve comparing to the loops and twists filament experiences with original MMU2 holder. Also, implemented approach doesn't expos filament to any noticeable stretching or compressing forces.

  2. Distance between printer and holder doesn't mater and can be any as long as PTEF tube allows. You can use provided tube connector to extend the tube if you need.

Best regards,
Alexander K.

Comments deleted.

This looks great. One question though... it looks as if the filament rubs against the spool wall, and the frame prior to entering the loop / wheel area - couldn’t this cause issues with additional frictional resistance or possible jams - especially when the filament starts to run low and needs to travel at greater angles off the spool and round the corner?

Originally I designed it with an input guide in mind. But after using the holder with different spools for a while I discovered that it actually doesn't need guide and it is better let the filament to find best path and position by itself. Any guide just constrains the natural flow and puts unnecessary tension on the filament. But to be on the safe side, the input hole is designed to accept 4mm PTFE tube. In case the tube is used, it allows avoid any sharp corners and minimize friction.

Best regards,
Alexander K.

Thanks for the reply. I look forward to printing my own!

Nice. I really like the solution for the rewind.

I think I might add some feet for the bottom bar so that they can free stand (if that is ok?) unless you already have some. I move my printer around and don't always use all 5 spools.

Actually both sides of the holder already have bases wide enough to support a spool without the connecting rail. The rail is just to keep everything tight and true.

Best regards,
Alexander K.

Hey mate, Nice take on the whole issue , Got a video of it working?

Cheers

Hi proofbenny,

Done.

Best regards,
Alexander K.

Thanks mate, 1 more quick question , whats the total width , just want to make sure sure 5 will fit on top of my table

36-40mm from installed spool on the filament guide side and 16-20mm on the opposite side. Depends on spool construction. In general with standard Prusa 90mm spool it is just ~15mm wider comparing to the stock Prusa holder. With no additional space required infront or behind.

Of course the holder can accommodate spools of almost any standard size. I also set the holders with an offset like on first photo. It allows easy access to the filament guide and also saves space.

Best ergards,
Alexander K.