QU-BD Extruder Modifications

by bdring, published

QU-BD Extruder Modifications by bdring Dec 21, 2012


My QU-BD extruder was stopping a lot so I made some modifications. The primary problem was the way they push the filament against the drive gear with a set screw. I switched to a spring loaded idler pulley. This will work with the stock QU-BD drive gear, but I switched to an MK7 style drive gear. The extruder is super reliable now.

There are two versions of the parts to allow you run the filament through the right side or left side. You need a 4mm I.D. x 13mm O.D x 5mm thk bearing (624), a button head 4mm x 10 screw, a 4mm washer and a spring. I used a 3/8" x 1-1/8" x 0.047 spring from a Home Depot assortment pack. The other parts are available a lot of places, but I bought mine at McMaster Carr.

It all fits within the width of the motor, so two can be run side by side.

I have a wiki page of all the things I did to tune up my QU-BD extruder here... buildlog.net/wiki/doku.php?id=ord_bot:qu-bd_extruder_improvements

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Thanks for this design. My QU-BD extruder completely fails to grip the filament at all, I'm sure this will help.
My extruder has been upgraded to Makerbot MK8
which material have you used to build this part? Would it work with PLA too?

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1. Select the version you need depending on what side of the shaft you run your filament through.

2. Print the parts.

3. Use a 3mm drill to clean out the holes.

4. Assembly the lever, bearing, washer and screw. You should be able to "self tap" the screw into the lever.

5. Assemble everything on the extruder except the lever. There is a little bump on the spring block that points towards the motor. This prevents it from rotating.

6. Install the lever with the spring. Hold the spring compressed while installing the screw that goes through the fan, heatsink and lever into the motor. Make sure you don't over-tighten the screw and lock the lever in place.

Inspiration came from this thing thingiverse.com/thing:15718
Thanks for this design. My QU-BD extruder completely fails to grip the filament at all, I'm sure this will help.
My extruder has been upgraded to Makerbot MK8
which material have you used to build this part? Would it work with PLA too?
Looks like this is the spring pack: homedepot.com/p/t/202045468?storeId=10051&;langId=-1&catalogId=10053&productId=202045468&R=202045468#.UlXkP2Se-Tg $4 with 5.99 shipping.....
Worked perfect :) .... I'm making parts again thanks. I bought the pack of springs for 4 bucks and first spring worked out great now I have 83 spare springs lol.. Home Depot #471 864
Any chance you have a DXF file for this? I would like to make one with my cnc, since I don't have the 3d printer working well enough to print this for. My QU-bd
Got the item number for that bag of springs? I couldn't find one that fit this size when I went to the store.
Should this be made out of abs or pla ?
Just added this to a new built Hadron w/QU-BD extruder and it worked perfectly! Fantastic design and glad it has enabled my printer to work without fault. I am surprised the QU-BD people haven't contacted you to ask to add this to all there future orders. Thanks again.
The holes in the part for the M4 screw (for bearing) seem too large. The screw just fall in and I cannot thread it in to stay.
It works fine on my printers, but I could see how variations in slicer settings could make that not work. Try tweaking some settings. I could post the STEP file so you might be able to shrink the ID of the whole.
I was able to modify the stl files and it works great now.
I'll upload the new parts tomorrow.
Step file wold be good. Everything else I print comes out right on as far as holes go.
Two months ago, I designed a similar mechanical structure of the extrusion head.Feels it has a few flaws:

first, the extrusion force is not enough

second,the extruded filaments don't straight enough
Would you be willing to modify this to work with a nema 14 motor. I know it probably won't work but I would like to give it a try.
You would need to create a new aluminum mounting block for the nozzle and figure out a new fan. It sounds like a lot of work without much hope of success.

What is your goal here? Is this for a speacial light weight application like a Delta Bot?
Does anyone have a photo of an ord bot with the ad-bd
Dual extruder mounted? I bought the complete kit that came with both. I just need a visual to get an idea how things are oriented.

I love the mod Bart!
Looks really nifty. May I ask what carriage you are using to carry your QU-BD extruders?

I have 3 QU-BD extruders and I am not sure how to best use them in a project.
I use it on an ORD Bot. I have it setup for dual extruders, but only one is installed do far.
If only one could get all the parts for an ord bot.
RepRapDiscount has kits available, and the quality of the machined parts is awesome - take a look at my posts on buildlog.net.
I don't see any kits available but maybe I'm not finding them.
roger, thanks :)