@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.
@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.
After more research I have found multiple instances where Clearpath Servos are very picky about the signal voltage. Ive designed a small level shifter board and sent it off for a prototype run, I hope to have it in about a week or so. I will be shifting the signals to 12v.
Once the boards and components arrive Ill test the boards, then test them with the servos and ill update.
I use Notepad++ works flawlessly.
4.99v on 40
4.97v on 41 Likely due to the R18 and R20 tolerances.
Did the same test with the servo encoders with the following results:
RAS 6.2 RAS 6.2
3600 pulse/rev 3600 pulse/rev
Servo Encoder at X0 Y0 Driver board position at X0 Y0
A B B41 B40
-12564 23112 -49695 13499
-12289 23124 -49695 13499
-12031 22945 -49695 13499
no change with or without RAS
Unless you have any other ideas I feel like the Clearpaths are not compatible with the 1XD board for some reason, Ill contact Teknic to see what their thoughts are.
@dc42 ill check them when I get off work today, and I'll probably shoot teknic an email since they state 5-24v for signals and get their input.
I assume the 5v regulator also provides power to other ICs on the board?
Would it be possible to bodge a simple board that sends 12-24v to the servos and use a resistor divider back to the 1xd?
Is the 1xd schematic available yet, or will it be?
@dc42 correct I have all positive pins connected to the 5v on the header with the dir, step, en pins. And those pins are directly attached to the servos.
The clear path manual does mention 5v minimum for the inputs and also states that less than that may work initially but will eventually not. I'm thinking the less than 5 volts is the issue here.
I mentioned the currents because the 1xd page mentions that they can only sink 10ma, and I assume that is through a 500ish ohm resistor. If that resistor is a 5% tolerance that would put the max current bellow 8ma.
@dc42
Absolutely:
I removed Homing from the gcode file, but I dont have a start,stop, or cancel.g
here is the console text, there was one instance where I didnt do a G1 X0 Y0, but you will probably see that. It looks to me that the 1XD boards are receiving and sending commands correctly. please verify my observation. console.txt
Here are the current ratings of the clearpaths:
5 VDC - Min 8 mA
12 VDC - Min 9 mA
24 VDC- Min 12 m
All of the pins are rated at 10ma/Pin, what is the max of the 5v common?
If that sink current is limited by a resistor its very possible that we could be under 8ma@5v if using a 5% @ tolerance resistor @ 10ma Max per pin.
@Teknic_Servo any info you can add to this?
#2 is interesting.
Would it help if I hook up some external 2209 or 5160 drivers to the 1xd boards and swap in some steppers to see if the results change?
@dc42 increase the speed and micro stepping. It happened significantly faster with higher speeds and step rates.
@dc42 Curious, do you think the same issue occurs on the tool board? but is less noticeable due to it driving an extruder?
Also Im trying to think of an easy way to remove all commands from the Gcode except for X/Y movement, as id like to do that same debug test with only the X and Y axis operating. Because earlier testing led me to believe that the issue was occurring during elevated processor usage on the Duet 3.
In my earlier screenshot of the Clearpath "oscilloscope" it looked as if the Servos and the 1XD boards had a slight pause in receiving commands while the Duet was doing something, this pause was between 150 and 250ms. I would notice it during Wipes, Z axis changes, and Part Cooling fan changes.
I have no idea if this is on the right track or helps you at all though.
@dc42 I had done a similar test by compairing the reading from the servo encoders. However I have installed the firmware and here are my results:
B40 9999 10040 10040 9855 10024
B41 -53195 -116286 -116286 -116087 -116257
definitely collaborating your results.
There is a Kinimatic bed mount system available for the Railcore produced by Mandela Rose Works:
Kinematic Mount
@dc42 im glad that im not crazy lol. Ive got full faith in you figuring it out!
thanks!
here is a more up to date config, that is actually printing right now (with shifting) config (1).g
and here is a the console output after running a few M122 commands for the 1XD boards and the main Duet console.txt
This was while printing the standard Benchy model. no hiccups at all. But plenty of shifting, there are no skipping/slipping belts.
config.g This is the config used with the servos.
Short move stress test.stl I designed this simple tower/gear type object to have constant changing directions. It gave me consistent issues with the servos.
I was running at an equivalent 18x microstepping in the later tests and 40x in the first tests.
@dc42 when I get off later ill send the config file I was using with the servos, and the test print i created that consistently produced the failure.
@dc42 im at work and can't look at that gcode file, but if it does t use steppers attached to the main duet 3 as well it wouldn't reproduce the problem.
I did extensive tests of just the x and y axis with no other actions from the duet with and could not recreate the problem. The file I used was about a min long with a high feed rate. It included circles, squares, zip zags, and even a 1mm oscillation. Id run it dozens of times with no errors or hiccups.
But after this hurricane hits us in the Carolinas, im going to put the servos back in and ill do any and every test you want me too, even if I've already done it so that we can figure it out.
Thanks!