I finally got my extruder working reliably. While it works fine, I would still like to make some improvements. I don't like the PWM controlled DC motor. PWM control seems a little arbitrary and highly dependant on the load. I would rather be able to set the speed via RPM. I would also like to run the feed a lot faster. This will make changing the filament on a bowden cable system a lot easier.
I like some of the worm gear systems I have seen, so I decided to give one a try. I think this will work well with a stepper as a stepper should really be geared down.
I came up with this design. I have the parts on order. This uses the worm gear as the drive. There is a bearing that pushes the filament onto the gear. I am using a spring plunger as the method to push bearing. I will start with a traditional extruder then move to a bowden cable version and the MK5 heater.
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