Trouble Shooting Universal Stepper Controller with Gecko Interface

Just checked again and getting good signals on the board.

I checked one then the other a few times, and they both do have different states.

3DTOPO wrote:

I'll go check the encoder readings again - but I just saw some crosstalk from X to W and nothing is connected to the W encoder (or even step/dir).

I manually moved the X encoder and saw both the X and W pos flickered between 0 and 1. Since nothing is connected to the W, would you think it might be time to buy a new USC?
 

Yes, with nothing connected, the encoder inputs are totally floating, and can pick up any stray interference.  If they are actually connected to an axis in HAL, they should be tied to ground, to prevent false following error trips.
Jon

Ah OK, that makes sense. Thank you.

I guess I don't know what to do next other than buy a new board; the encoder signals check out on the board.

With good signals there, what else could it possibly be?

One thing about the chatter is that it also happens only on the X (other than W).

The Y and Z (the two functional axes) don't jitter at all.

I connected my X servo (motor/encoder) to use Z as X, because I only need two axes to get some work done (until I order a new board and receive it or am able to fix it). Also, seems like good trouble-shooting because it is using the X servo.

The X servo is functioning nominally through the Z channels (eg using 2 instead of 0 in univstep_motion.hal).

Please let me know if you think I should buy a new USC or if there is anything else to check.

BTW: I ordered the USC card 10 years and one week ago. And is lucky board "0123".

That is 10 hard winters and 10 hot summers in a shed that isn't climate controlled. 

3DTOPO wrote:

BTW: I ordered the USC card 10 years and one week ago. And is lucky board "0123".

That is 10 hard winters and 10 hot summers in a shed that isn't climate controlled. 

 

Well, I wonder if the board has accumulated a bunch of conductive dirt on it?  I had one customer who heated his shop with soft coal, and his boards came back to me often completely coated with black dust.  I cleaned them, and then they worked fine.  If something is blown out on the USC channel # 0, it seems unlikely the same thing happened on the unused channel # 3.  Way back in 2010, my soldering process was not as good as it is now.  Also, I have a note that your unit was blown out by a sparking wire, and I repaired it in April 2016.  Possilby some of that repair soldering has gone bad.  If you buy a new board, it will come with 2-part screw terminals, which should make all troubleshooting easier.
Jon

The first thing I did was blow it off with compressed air - but it could still be cleaner. The dust around here shouldn’t be conductive though.

I agree that would be freakish for USC channel #0 to get damaged in an identical way as #3.

I’m going to catch up a bit and get a bunch of things cut, then I am going to go back and completely rewire both X and W. If they both still don’t work after that, I will buy a new USC.

IIRC I had a new chip sent out in 2016, but that board was not sent in, in-part because it is soldered. I did send you the PWM controller for repair, around the same time I guess.

That’s awesome, switching the board will be pretty painless with the screw terminals, and as you say make trouble shooting easier.

Oh one more question, do you think the GeckoDrive (or its wires) could be the culprit? It is one thing that hasn’t been swapped out and the one thing in common when switching from X to W.

3DTOPO wrote:

The first thing I did was blow it off with compressed air - but it could still be cleaner. The dust around here shouldn’t be conductive though.

I agree that would be freakish for USC channel #0 to get damaged in an identical way as #3.

I’m going to catch up a bit and get a bunch of things cut, then I am going to go back and completely rewire both X and W. If they both still don’t work after that, I will buy a new USC.

IIRC I had a new chip sent out in 2016, but that board was not sent in, in-part because it is soldered. I did send you the PWM controller for repair, around the same time I guess.

That’s awesome, switching the board will be pretty painless with the screw terminals, and as you say make trouble shooting easier.

Oh one more question, do you think the GeckoDrive (or its wires) could be the culprit? It is one thing that hasn’t been swapped out and the one thing in common when switching from X to W.
 

The Gecko drive is pretty well isolated from the encoder/USC connection.  That is because in E-stop, the Gecko drives are powered OFF by the Gecko interface.  So, any funny business on the Gecko drive cannot affect what the USC sees.
I guess we swapped a USC and a UPC serial numbers when you returned a board to me.  My notes indicate several chips were replaced on ONE of the boards.
Jon

Thanks for the info and all your help.

Yeah so I fried the USC in 2015 and you helped me trouble shoot a fried GeckoDrive (on the Y), and you sent me a new ROM. In 2016 I sent the UPC and you found holes drilled through the mosfets. 

I swear on my life, I would never do that! Guess that was still my responsibility -- I should have given my "assistant" much more specific instructions! 

To show my appreciation, I gave you credits in my laser cutter test video: