mdrVB6 wrote:

When you say it "jitters back and forth", do you mean that it does not move in a consistent direction and alternates between moving the filament towards and away from the hot end, or do you mean that it just kind of roughly ticks along and produces an uneven line?

If its a rough ticking but at least moving in the right direction, I would agree that its a vref issue.  These can be VERY sensitive, but if you have taken a multimeter to it and patiently tried the entire range then it does sound like a bad driver.

It jitters back and forth approximately 1-4 degrees in one direction then in the opposite direction. Net rotation = 0. No filament is extruded.

Oh, okay.  That is what my motors did when I had it assembled wrong on the plug, so that the 4 motor poles were not going to their matching terminals.  Did it used to work right, or came from the factory not working?  If it used to work, then I would think its a driver issue but if it never worked, it might be a misassembled plug.

Edit: try comparing the various colored wires on the E2 plug to the E1 plug.  Are they in the same order?

When you say it "jitters back and forth", do you mean that it does not move in a consistent direction and alternates between moving the filament towards and away from the hot end, or do you mean that it just kind of roughly ticks along and produces an uneven line?

If its a rough ticking but at least moving in the right direction, I would agree that its a vref issue.  These can be VERY sensitive, but if you have taken a multimeter to it and patiently tried the entire range then it does sound like a bad driver.

It jitters back and forth approximately 1-4 degrees in one direction then in the opposite direction. Net rotation = 0. No filament is extruded.

If its a rough ticking but at least moving in the right direction, I would agree that its a vref issue.  These can be VERY sensitive, but if you have taken a multimeter to it and patiently tried the entire range then it does sound like a bad driver.

worldburger wrote:

wardjr wrote:

That sure sounds like a  VREF issue to me.  If what you say is true I would suspect a bad driver.
I think I'd be asking SD  for a new board as I assume the drivers aren't removable.

Ah, that's unfortunate: I was hoping someone would say "thats simple, do this".  I appreciate the reply, thanks!

I could be wrong!!!

After testing the other ports and stepper motors, I'm pretty sure it's the output of the board.  I submitted a ticket to SD.  We'll see what they come back with.  Will post an update when I hear from them.  Here's to hoping it is something simple!

wardjr wrote:

That sure sounds like a  VREF issue to me.  If what you say is true I would suspect a bad driver.
I think I'd be asking SD  for a new board as I assume the drivers aren't removable.

Ah, that's unfortunate: I was hoping someone would say "thats simple, do this".  I appreciate the reply, thanks!

I could be wrong!!!

That sure sounds like a  VREF issue to me.  If what you say is true I would suspect a bad driver.
I think I'd be asking SD  for a new board as I assume the drivers aren't removable.

Ah, that's unfortunate: I was hoping someone would say "thats simple, do this".  I appreciate the reply, thanks!

PROBLEM: my left extruder (extruder 2 on the board) gear jitters back and forth.  I can only get it to rotate if I adjust the speed above 25 mm/s.

The problem seems isolated to the E2 port coming off the motherboard.  Extruder 1 works fine.  When I switch the E2 and E1 plugs in the motherboard (so E2->Extruder 1, E1->Extruder 2), the symptoms transfer to the right extruder (1) and the left extruder (2) rotates as it should.

I have adjusted the trimpot throughout it's entire range and it does not solve the problem.

I have since followed SoliRyan's suggestions of trimpots for E1 and E2 to 1.5v (this seemed high so I adjusted them down to approx 0.3V) as well as X, Y, and Z to 1V.

Suggestions?