Extruder Motor jerking

I recently built a mpcnc using all the part from this site, including 3D prints. I also got a extruder for it from here.after loading the filament and finally threading it down the hole I started a print using repeiter host with all your slicer settings. The extruder motor wouldn’t push the filament down and the gear keeps slipping on the filament. I have tried all the way up and down with the spring. The relay I got for the extruder stepper is set to around 0.45v. Any surgestions on why it would do this?

YouTube vid

More power!

I have me stepper drivers anywhere from .5-.8v. up the power and keep tabs on the extruder motor temp. They seem to use a few different steppers so I a can not give you an exact number.

Well, can’t say I’m not impressed by the speed of your response! Are you hitting refresh? Thanks I will try it.

Ok I upped it to 0.7 It helped but it still didnt resolve the issue.I looks like the hot end hole/barrel is too small for the filament. When I push it in it shaves off one side of the filament, like its digging in to the corner. I took out the gear and the bearing and the filament moves easly into the hot end hole. It seems the gear is too big?

Will add video in 10min

shaving off filament

easy moves in barrel

btw filament is 1.76mm with calipers

The bearing is supposed to push the filament into the gear, so that will center the filament to the hole. Some shaving can occur, but it shouldn’t affect the feed.

I had to look up that style extruder because the gear was straight. My gear looks like this. I don’t have a printer from here though.


Hmm, well it does the shaving effect with or without the bearing on. to the point wear it digs in so much it wont continue. Will the spring ajustment fix it? I have mess around with different heights a bit.

Not sure, it looks like you already have too much spring tension from that first picture.

I would say a little less spring tension and maybe I got your throat a little too close to the gear. I would say just back it off one full turn by unlocking the 10mm nut spin the whole hot end assembly and tighten the 10mm back up.

Did both helped alot, still a bit of shaving but its not effecting the prints.
Thanks Guys

I ended up printing a little spacer to go behind the bearing. That lined it up between the entry hole and the throat. It’s much easier to load and I can leave the spring much looser than before. If you sight through the entry hole you may see how far off the bearing is.