Feeder Stepper Motor Modification for Extrusion Issue

[dantheteaguy 0]

Hi y'all, I could use some help. For an engineering project at my university, we had been tasked with creating an attachment for and modifying an Ultimaker 2 to allow for the heated mechanical extrusion of a bioscaffold material. We were able to figure out the necessary modifications for the heating and attachment, but we're having a bit of difficulty with the extrusion itself.

 

The printer would no longer be used to print filament, so we decided to retask the stepper motor in the rear meant for the feeder to take on the role of our drive shaft within our mechanical syringe compression tool. After rewiring and moving the motor we were able to confirm it runs through using the Maintenance-> Advanced-> Move Material setting, but it just won't move during a print. We've tried adjusting the Current E, the material flow, and doing a factory reset.

 

Would anyone be able to provide some insight into why it won't turn during a print but will during the Move Material adjustment and how we might be able to fix it? Any suggestions would be immensely helpful! Thanks!

[tinkergnome 927]

What's the printing temperature?

There's a firmware feature called "cold extrusion prevention" with a minimum temperature of 170°C per default, but it can be changed with a gcode command, see:

 

 

 

or...:

https://reprap.org/wiki/G-code#M302:_Allow_cold_extrudes

 

[dantheteaguy 0]

8 minutes ago, tinkergnome said:

What's the printing temperature?

There's a firmware feature called "cold extrusion prevention" with a minimum temperature of 170°C per default, but it can be changed with a gcode command, see:

 

 

 

or...:

https://reprap.org/wiki/G-code#M302:_Allow_cold_extrudes

 

 

Thanks for the quick response! We're trying to print at about 134 C maximum, and will need to print at lower temperatures. I believe it may actually be this cold extrusion prevention. I had seen it on a forum elsewhere, but was unable to find how to fix it. Thanks! I'll post about if I'm able to get it to work!