Hey! This thing is still a Work in Progress. Files, instructions, and other stuff might change!

Mechanical Paste Extruder

by bryancera Oct 8, 2018
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Hi Bryan,

Thank you so much for making your design public. Just completed the extruder today and started looking into the flow driver you have posted to accompany it. I don't have an electronics background and am having trouble determining the power supply (assumed 24v 3a), the correct resistors, and LEDs. Do you mind sharing links for those that are compatible for this build.

Thank you again for your time and assistance.



Great to hear! Please help me out by posting a photo under the "I made one" section here. Thank you!

The resistors should be around 200 ohm, and the LEDs are just SMT colored leds. The power supply is 12v, and the one I'm using is 2a.

Here's a short vid of soldering the resistors and LEDs:

Hope this helps!



Where did you get second t10 nut (for coupling leadscrew to plunger) ? Your link direct me to Amazon store but its just regular nut not keyed.


Found much cheaper tube alternative but will need to modify the files for 70mm tube diameter, could you upload editable 3D files as well to do this

Also your description says 30mm x 3mm O-ring (x2) but the links are gor 60mm orings, is it OD 60mm then?

and could you update the link to 5/16 brass hose fittings as it doesn't seem to work

Thank you!

also I think you forgot to add NEMA23 for the list of materials, is it 57x51mm 2.8A motor or 57x82mm 3A?

Hello, nice design. Need some advise. I am looking for an alternative for the container, and I found this...https://www.aliexpress.com/item/6-lbs-3kg-Homemade-Sausage-Stuffer-Stainless-Steel-Sausage-Filling-Machine-Sausage-Syringe-Meat-Filler-Sausage/32851120230.html
The nozzle might need some creativity (min 14mm) to get it to 4mm, but other elements look like OK. Would this be a bad idea?
Any thoughts welcome.

Good idea, the only thing it is not transparent( do you think this version may be better for refilling? https://ru.aliexpress.com/item/5-2-5/32851088872.html
for mini version something like this will work too https://ru.aliexpress.com/item/Transhome-Cookie-Gun/32952900794.html

for the nozzle can you just design 3D nozzle similar to what they sell but with reduced 4mm outcome? As I understand their nozzles are screwed in with a fixating nut anyway, so should be easy to change it.

Comments deleted.

I would like to learn more about the motor specs. In the given links, it seems like 1:20 ratio is suggested. Can you confirm that your build uses 1:20 gear ratio?

Confirmed! 1:20 and 1:30 both work. I updated this info in project description. Thanks!

I'm looking to prototype a paper mache system for burnable art structures and this design looks promising. I've been playing with different mixtures and seeing what will pump well. I'm new to designing with motors so I don't have a good feel for the strength of 1.1 nM at 20:1 gearing. In my prototypes I've been working with a air powered calk gun that in theory is pushing ~100 psi. This is ok for some mixtures but not all. I'm hoping to move to a worm gear design as the air pump design is very variable in power and noisey. Any sense whether this would be more powerful? I also found some other worm gear designs with 3 nM at 20:1 so might go that direction.

BTW, I work at Shapeways so seeing your 3d printed printed parts there makes me happy. Hopefully sales are good.

Yes, I think this could work perfectly for your project. I have been wanting to try extruding paper pulp, myself! Let me know if you end up using this extruder, i'd love to see the results!


What is the length? (ie: length of the polycarbonate tubing) Looking forward to building this!! Thanks for your work

roughly 18" - cut the 3' length (as seen in the link I provided) in half. This gives you two tubes.

I used a chop saw (actually a compound mitre saw) to cut mine, but this could also be done with a hack saw.

the ebay link is for 3' Length

Yes, that is the stock material. I meant in the actual build- 15"?

Comments deleted.

What's the total cost if you buy everything from your provided links? Is the flow control board really needed?

Prices on amazon seem to vary day to day - though I wouldn't imagine it would be too hard to follow the links and price it out.

The flow control board is not completely necessary - it is possible to control the stepper motor from your 3D printer motor board (I use a RAMPS). However, it can be difficult to fine tune exrusion settings - especially while a print is running. So it is possible to skip that part, but I would reccomend some external means of controlling the flow rate. You definately do not need my board to do this, though! For a long time I just used an arduino, a a4988 board, and a potentiometer to control the flow rate.

Hope this helps!


I am interested in board question as well, as for the costs the links provided don't give best prices with a bit of research you can get much better offers from China if you can wait for the delivery 2-4 weeks. here f.e

T10x2mm rod+nut 9.58$
extra nut T10x2mm 3.39$ https://ru.aliexpress.com/item/T10-10/32871718736.html

And yeah, by all means find this stuff cheaper elsewhere! I have had problems with shipments from China taking upwards of 6 months - so I tend to avoid it if possible!

In fact, I've got another project I plan to publish here - a CNC rover - that has been delayed thanks to a shipment from China taking 4 months (so far) to arrive. :(

probably a stupid question, but do you think it can be possible to use this instead of your metal nut?
I meant if cnc or drill hole on one of the sides to slide in original side bits that comes with the motor, similar to the holes on the motor shaft
or perhaps weld side bit to the side of this part

Only one way to find out! :D

I highly doubt this could be made to work. If the dimensions happen to be right (which would in itself be miraculous) there would be very little material to cut a key way from. This is why I chose to 3d print this component. But if you give it a try and it works, let me know!!


here is one even cheaper https://www.ebay.com/itm/1Pc-3D-Printer-LMF8LUU-LMF10UU-LMF10LUU-LMF12LUU-LMF16LUU-Round-Linear-Bearing/232721661901 I am thinking which extruder to choose now to add up all the costs, your version looks great, so if I choose it I will definitely try this out as on this bearing the wall seems to be thin with inner plastic, should be not to hard to cut it out on the side) size is pretty much similar a bit longer I think Size: LMF8LUU:8-32-45mm (Internal diameter - outer diameter -length)
I think maybe even possible to get 6mm one as it is shorter 35mm and remove the plastic, but this may not connect with 4 screws on top K dimention is smaller 22mm instead of 25mm, but worth trying here is sizes table as well https://www.google.co.uk/imgres?imgurl=https%3A%2F%2Fimage.dhgate.com%2Falbu_911493774_00%2F1.0x0.jpg&imgrefurl=https%3A%2F%2Fwww.dhgate.com%2Fproduct%2Flinear-bearings-lmf8luu-round-flange-linear%2F209244962.html&docid=_mlRmzva77V6nM&tbnid=M3gMbE_yUcIgJM%3A&vet=10ahUKEwjN7vOuhs_eAhWF6aQKHVgKADkQMwhBKAIwAg..i&w=805&h=984&bih=674&biw=1536&q=LMF8LUU%20dimensions&ved=0ahUKEwjN7vOuhs_eAhWF6aQKHVgKADkQMwhBKAIwAg&iact=mrc&uact=8

that probably will require to drill the 4 holes as well as the brass part seems to have 16mm diameter in 4 holes and LMF6LUU will have ф - 20mm and 25mm in LMF8LUU between them so holes will be wider then needed.

But another thought is to use top part of Anti-backlash Nut ? maybe it is possible to insert original side bit in it.
this links to rod and nut from China but seems to be much cheaper then getting it from amazon and probably ships worldwide.
I am thinking to get just smaller rod 100mm for 2.59$ to get that second nut.

Could you post the dimensions of that original side bits that came with the motor and attached to the original shaft?

I am not sure what the first component you linked would be used for here. Yes, is looks similar to the nut coupler I designed, but it would not function as such.

hey, is it not possible to fill in the tube by sucking the clay in like the syringe works?

The clay is way too thick for that.

Today I finally recived all the parts I needed to start the extruder.

So cool!! Please keep me posted on your build progress, and don't hesitate to hit me up with any questions you might have!!

The only thing that hinders me to continue is how to make an external speed controller for the nema 23.
I do not want to connect to my RAMPS 1.4.
could You help with that ... ?

MCanabal - absolutely. You can either build a simple speed controller with an arduino, a toggle switch, and a stepper motor controller (such as an A4988) and a potentiometer. I can help you with the wiring and code for the Arduino sketch if you'd like.

Or if you want you can build the speed controller I designed...

More info on that is here:
(note: this is a work in progress - so let me know if you have any questions)

I have already begun to print the parts, tomorrow I will continue with the rest that is missing.
I already ordered all the elements in amazon.

My question is how long are the M3 and M6 that I should buy?

Hey! I will look into these tonight, I forgot to record how long those were.

FYI - I doubt that the "nut coupler" will work as a plastic print. This either needs to be cast in metal, printed in metal, or machined. I printed mine in bronze/stainless steel through shapeways.

Bryan, a question, in the stl "nozzle mount type 1"
Could you add a 1/4 (6.35 mm) female thread to the tip?
is to add a quick connector 3/8 od x 1/4 fip Male?

It would be excellent !!!


this is so cool! thanks for all your hard work on this! I've wanted to build a ceramic printer for years, but i've been mostly put off by the air-compressor systems. I don't have access to anything elaborate like a dobot, or the custom printer you've built but I do have a kind of hack-y rostock and access to a couple of run of the mill prusa type printers. How successful could this sort of design be with those? like in the dobot it seems to be feeding via some kind of feed/bowden tube? or is it better to build a specialized printer around this kind of system?

Yes, with a hose/tube you could adapt this design to work with pretty much any printer. You may need to dilute the clay a bit more to work with a tube.

Looks really good!

Question: The gearbox rotates driving the lead screw. The lead screw can't turn. So, that square "Nut" at the top holds the lead screw from turning? Won't that create friction within the 1" square tube? Is the Lead Screw also held from turning at the other "plunger" end? Thanks

Great question!

There is actually very little friction on the square "guide" inside the square tube. It takes very little force to keep the lead screw from turning - i discovered this in earlier iterations.

The leadscrew is not completely held from turning on the plunger end - in fact this design uses a second leadscrew nut to couple the leadscrew to the plunger.

It is actually a bit hard to describe here - I will be sure to include this in supporting video documentation I plan to release in the coming weeks.

Thanks, Your IG assembly video is very helpful as well. Very excited about this project. Starting to learn Grasshopper:-)

This thing rules!! Saw it in action at Milwaukee Maker Faire. Thanks for sharing!