Clearpath Servos with 1XD Expansion

DOP

@dc42 @jballard86 Either of you ever figure this out yet? i just setup with 2 clearpath servos i see 0 hiccups but the layer shifts are real! i'm on version RRF 3.2 via duet3 + Pi4 SBC.

DOP

For others who find this thread: I just installed beta 3.3 and it's working correctly now, looks like root cause was in can communications.

jbergene

@dop and @jballard86 . Have any of you managed to produce a good looking print yet?
if yes What were the T timings you ended up using?

Best regards
John Henrik Bergene

jballard86

@dop I fixed it by abandoning it and going with a different hardware solution. My assumption after lots of trouble shooting is that the clearpaths en/stp/dir signals needed to sink more current than the 1xd could provide, or that it was a CAN issue. I ended up developing my own board that worked flawlessly.

jballard86

@dop said in Clearpath Servos with 1XD Expansion:

For others who find this thread: I just installed beta 3.3 and it's working correctly now, looks like root cause was in can communications.

If it was an issue in CAN, id assume that issue has been in all of their products that utilize CAN. its unfortunate that they left bugs like these in their code for so long unnoticed.

atlas_Clark

@jballard86 I am currently embarking on a project implementing the ClearPath SD servos with a duet 3 and 1XD and was wondering if you would be able to provide any wiring advice or images? I've followed the documentation as best I can for wiring the step/dir/en to the 1XD with no luck and this post is one of the very few demonstrating exactly what I am attempting to create.

alankilian

This looks like all you should need for wiring information and timing.

However I don't believe the original poster got these servos working correctly. (I may be reading it wrong.)

@dc42 said in Clearpath Servos with 1XD Expansion:

I've checked the outputs from the 1XD board with 620 ohm load resistors, using your configuration (M569 P40.0 S0 R0 T2.7:2.7:2.7:2.7):

The signal amplitude is 4.8V

The step pulse width ls never less than 4.1us

The smallest interval between step pulses I saw was more than 100us

The end-of-step-to-direction-change hold time looks consistent at 8us, however direction changes are not very frequent so it's hard to be certain that there are no shorter ones

The direction-to-step setup time appears to be very long indeed

Here's an example of a step with a direction change afterwards. The 'scope is looking at the STEP- (yellow) and DIR- (blue) output pins of the 1XD, with the 620 ohm load resistors connected between those outputs and the common +5V output.

PS:

The voltage across the 620 ohm resistor connected between Enable- and +5V is a little lower, 4.78V. This is expected, because that pin is not driven by a high current drive pin of the microcontroller. But it should still be enough, because few device providing 5V output signals would provide more than that.

Please confirm that you have connected the ClearPath A+/B+/Enable+ inputs to the common +5V pin on the 1XD board, and the ClearPath A-/B-/Enable- inputs to the individual output pins.

atlas_Clark

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chine

Any update on this? Did anyone get their setup working?
I saw Pantheon Design is using clearpath on their new printer but it sounds like they created their own hardware to use duet/clearpath.

Thanks

Edkirk

@chine Several years ago I built a Corexy to test Clearpath Servos, I had no problems. Absolutely awesome performance. Looking through the above post I didn’t see any mention of power voltage and current to power the servos. I used a power supply from Clearpath for Servo power. I was initially concerned about signal voltage from the duet board for step/direction but there was no problem. I set Clearpath resolution to get close to my original steps per mm in config.g. I found the servos were over kill for a 3D printer, they are no better then the signal from the board just producing slightly better then a good stepper motor. They are very quiet. I transplanted the servos to my CNC router where I needed the extra power. Photo of the original test printer.
Ed Kirk

SignPostMan

@jballard86 Do you have these boards available for sale? I have developed my machine around Clear Path servos without knowing this problem until finished with the project. Looking for the easiest answer to solve.

SignPostMan

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alankilian

@signpostman

I haven't read this entire thread so I don't know what you mean by "Is there any other way to connect my ClearPath Servos to the Duet 3 main board?"

If you have specific questions, you should probably start a new thread with those questions and I'd be happy to help.