Extruder motor reverses direction with resistance

Ask the MakerGear community for assistance...
Post Reply
AndyNav
Posts: 8
Joined: Wed Jun 29, 2016 4:03 am

Extruder motor reverses direction with resistance

Post by AndyNav » Wed Dec 27, 2017 9:14 pm

I was on the tail end of a small print and the printers started making a grinding noise, turned out to be the extruder motor. With very slight amount of resistance(the amount provided from the filament is enough) it will reverse direction until it hits resistance and will reverse again. I attached a video or this for reference (or at least I think I did).
Is there a fix for this beyond replacing the motor?
Notes:
It is a M3-ID running from octo-print.
In the video I am hitting extrude, though the same thing happens with retract.
it still makes the noise without any resistance

Thanks,
Andy

AndyNav
Posts: 8
Joined: Wed Jun 29, 2016 4:03 am

Re: Extruder motor reverses direction with resistance

Post by AndyNav » Wed Dec 27, 2017 10:38 pm

This seems to be resolved now.
I am able to extrude filament from the control panel without issue.
I opened the stepper motor open and found a fractured solder joint on one of the connector pins. re-flowed that joint, reassembled and so far all is well.

I found that the two outside pins of the connector had particularly ugly solder joints. These are the pins that the mag wires are soldered to on the primary side.

Andy

User avatar
ednisley
Posts: 998
Joined: Fri Apr 11, 2014 5:34 pm
Location: Halfway up the Hudson
Contact:

Re: Extruder motor reverses direction with resistance

Post by ednisley » Wed Dec 27, 2017 11:34 pm

AndyNav wrote:it will reverse direction until it hits resistance and will reverse again
One of the windings in that motor isn't getting any current. The other winding thrashes the motor around, with any external load nudging it one way or the other.

Turn the power off, then verify the connections from the RAMBo pins to the motor. Use a multimeter to check the continuity of each wire from end to end, by poking a paperclip into the socket ends to establish a connection.

It's faintly possible a winding has broken within the motor, so use the multimeter to check continuity for each winding. If you find one pair with a few ohms of resistance and the other pair with no continuity (infinite resistance), you've found the problem.

Post Reply