CAN and potential sync issue when performing QGL

General Discussion
1

Hi all,

It is possible that I’m experiencing an issue already reported in " CANBUS Communication timeout while homing Z" thread.

No errors when Z-homing, but intermittently (more often when I left printer to heat up for a while) when going through QGL, I’m geteing an error:

  • visible delayed Z lift move after probing one of the corners.
  • visible slower (with pause) move to the next corner.
  • “BLTouch failed to deploy” error.
  • restarting the same job always sucessful.

I have tried different probes (BLTouch, CR Touch), different can toolboards, different can speed and network queue size. Always the same. I’m not sure but if it helps I can post Kilipper log after this happens next time.

Thanks

2

I’ve also seen the visible pause before lift

3

May I please bump this topic? The reason is that I’m frequently getting these delays and "“BLTouch failed to deploy” errors when perfroming QGL and - less frequently homing Z.

Based on advise from @koconnor in the CANBUS Communication timeout while homing Z thread. I took fresh canable and updated with the latest canable_fw from GitHub - candle-usb/candleLight_fw: gs_usb compatible firmware for candleLight, cantact and canable (built like 2 days ago)

… and got he same issues almost instantly. Would it help if I post Klipper log straight after this happens again? Apologies for bringing this up again hope I’m not annoying anyone.

4

Yes, include a log from the event (and make sure to invoke an “emergency stop” immediately after the event). Without a log, there’s nothing anyone here can do besides speculate.

Be aware though, even with the log, there’s not much appetite to debug bltouch issues. Those devices are known to be flaky.

Separately, when I perform probing on my Voron2 I also get occasional probe attempts that seem to “pause” a moment more than other attempts. I haven’t investigated this in detail, but my assumption is this is just due to minor timing differences during the synchronization of micro-controllers. At least on my printer, the pauses do not have any adverse effects.

Cheers,
-Kevin

5

klippy.log (2.4 MB)
Thanks @koconnor , the log is attached, I’ve hit the emergency stop icon as soon as the error happened. Appreciate if you could have a look.