Would love some guidance on an issue I’m trying to resolve.
When a film roll completely unspools onto another, both reels start spinning fast because torque mode is still turned on for 1 second until the “no film detection” triggers and set odrive motors torque and vel to 0.
The odrive reel motors continue to spin because of inertia.
What I would like to know is how could I “brake” the reels to a stop? Right now I just use my hands and pinch the reels to a stop. If I let it spin it will stop spinning after a minute or so.
It does stop but it’s an abrupt stop because the reels are spinning freely due to inertia and it has no idea of what velocity it is at , so when velocity is set to zero, it cannot ramp down, it just stops on a dime.
Try lowering the gains for the velocity controller. set vel_integrator_gain to 0, and lower the proportional gain by quite a lot. (you aren’t using the position or velocity modes for anything else so doing this won’t affect your torque control)
When I rewind or forward at high velocity, with both motors in torque mode, sometimes the odrive stop working and I get this error:
In : dump_errors(odrv0)
system: no error
axis: no error
sensorless_estimator: no error
axis: no error
motor: no error
sensorless_estimator: no error
encoder: no error
controller: no error
This started to happen today, was fine before - what could this be?
so weird, it started happening more and more yesterday was able to run the machine all week without issues -
Thinking about it… I added two loadcells (on each reel) for measuring tension 2 days ago, which are close to the motors. Could this be interference? I think they are also SPI devices. I use the loadcells data to adjust torque values in realtime. Here are the load cell amps I use: https://www.sparkfun.com/products/13879
Would having shielded cables for both the SPI encoders and the LoadCells help me? Right now the SPI encoder cables are breaded and the loadcells cables are in a non isolate but thick sleeved 5 wire cable.
If I can’t make this work with the SPI encoders, would going back to index search encoders solve this issue? Would really love to keep SPI encoders because I’m spoiled being able to start the machine without index search and going back would be a real depressing situation.
Ok will try to move the cables a bit. I added the ferrite rings on the motor cables and did 3 turns. Should I add ferrite rings to encoder cables as well?
When I run odrivetool dfu it says I’m about to upgrade to 5.04 same version I already have so I didn’t do it - would you be able to send me a compiled firmware?
You had mentioned something about that in a post above and was not sure I understood what to do - if there’s a new 5.0.4(with the fix in) I’ll do that - Please let me know, otherwise I’m really stuck and would need help getting a compiled version.
@towen@Wetmelon so the odrive crashed again with the CUI encoders. I noticed when this odrive is connected to USB (with isolator) it was "disapearring / reconnecting by itself)
So I swapped the Odrive with a brand new one and so far everything is working, same wiring everything. I don’t have the mental strength to try the SPI encoders with this new odrive but maybe another time - I need to continue working on more pressing issues.
Can I send the board for a replacement? It was purchased September 6th 2021
I sometimes find that the SPI encoders work until I raise the supply voltage past about 40V, and then I seem to be more likely to get ERR_ABS_SPI_COM_FAIL which persists until I power-cycle the encoder itself (i.e. there is a problem with noise being coupled from the motor to the encoder which causes the encoder itself to go into an error state, and the magnitude of some kinds of EM noise goes up with the square of the supply voltage)
It would be weird if you have a dud ODrive causing this though. I suppose they are running different firmware? I suspect that is the only difference but I could be wrong.
I don’t think the ODrive team would have any objections to you sending it in for a replacement though, because they should be able to repair it pretty easily if anything is obviously wrong, and even if they can’t repair it but they can find out why not, then they have valuable info for their design. Plus I think any basic warranty policy would definitely cover something purchased less than a year ago without question, unless it had been obviously abused in some way, which yours hasn’t.
I have a 24V 20A Mean Well PSU powering the machine.
It could be luck that it’s working right now. It was crashing randomly, do you think the power supply could be dying? I can try swapping it for a new one. Not too sure how to test if it’s dying though.
Ok cool - I’ll do that, in any case they can verify and see if it has issues and if there are none, then it will help diagnose the issues.
Actually I’ll try swapping the PSU later this week and give SPI another go, I can’t do this now though - I have major PTSD of seeing these SPI fails errors all weekend long