Silicone Rubber Tubing

Hi, after getting my extruder connected to my ultimaker I was ready to print using silicone rubber. The problem I have now is that getting silicone rubber through the teflon tube is near impossible! Any tips on how to print with silicone rubber? Mainly getting the silicone through the tubing so it can properly extrude?

Can you provide more details on what type of silicone you are using? Is it from the hardware store? Or is it a custom mixture? What is the work time (i.e., how much time do you have to work with it before it starts setting)?

Please provide as much information as you can. We find hardware store silicone to be a pretty easy material to print, but there are certain ones that are more difficult.

Hey @WilliamLu! Welcome to the forum!

Couple things to make sure:

  • You are using only the required amount of tubing to reach the bed. I find about 1.5ft is appropriate for the U2.

  • Push as much through by hand, then load the cartridge in the Discov3ry.

  • Enable cold extrusion.


  • Ensure the correct EEPROM is being used (~14000 for U2).

    M92 E14000

  • Manually extrude the material (Cura, Repetier, Pronterface) until it comes out the tip before printing.

One of our trusty engineers @Malcolm has made a custom Gcode file for the U2 that will help purge the tube. Could you post here? Use CTRL-K to format code.

Hope this helps you get started! Happy Pasting!

Hey William!

I’ll post the as soon as our Ultimaker is done printing and I can rip out the SD card! It can also be adapted to be a custom button on your host controller (Repetier, Pronterface, etc)


The material is this:

Can you confirm a couple more details? What does it say on the back of the package for “work time” or “sets in X minutes”? Also, was this a recent purchase? (Sometimes older material has more problems printing than newer stuff.)

@WilliamLu, did you find a solution?
I have the same problem here, I’m trying to print in silicone but I can only push about 50 mm by hand then I load the cartridge in the Discov3ry and I can push maybe 50 mm more but it’s impossible to extrude. I cannot even reach the middle of the tube.

@Charles_Mire, I tried several hardware store silicones and they are all the same: It says it dries in 10 minutes/24 hours for the middle. They stay fresh and liquid. I have had them in cartridges for days and they are still good, I just can’t get them through the tubing. Would you have suggestions? Thanks.

Hi @Malcolm,
Could you share your custom Gcode for the UM2 that helps purge the tube? That could help maybe.

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