I am building a paste extruder based on open source design. However I am having some issues with the stepper motor (NEMA17 Stepper Motors (62 oz) - Model: 1.8° - 1703HS168A ). Video link see the video : It appears that the motor is slipping (skipping?) at the coupler while trying to push the material through.
Specs: ACME 8 mm thread >>8mm-5mm coupler>> 5 mm motor shaft
I have increased the amps upto 900 mA from whatever the default was in Prusa i3 Mk2. I also set the extruder steps to M92 E 70 (steps/mm).
As you can see i am using a 50 ml syringe with about 25-30 cm tubing (internal diameter 4 mm).
Any Ideas what i can do to sort it? I am planning to increase the stepper current further and hopefully results in greater torque to push the material through.