Topics created by usinjin

@usinjin The 'easy' way to do this would be have the Z compensation reported in the Object Model, and use that. However, this isn't currently reported in the Object Model. I asked @dc42, who replied:

We could consider it for 3.6. Easiest would be to report the last computed height correction, which would be the correction at the endpoint of the current segment.

Would that suit your purpose? You could enable segmentation (see M669) would also allow the compensation to be updated more frequently on long, straight moves.

If so, please raise a feature request/enhancement on the firmware Github repository: https://github.com/Duet3D/RepRapFirmware/issues

Otherwise, you're going to need something that can read the XY position, and be able to compute the Z offset (ie have the mesh .csv file), and feed that to the pen motion control, in a timely manner. Something like that might be better done by a Raspberry Pi in SBC mode.

Ian

@usinjin

First off, I am no expert with tuning the 1HCLs. That being said I have been using them since they first came out.

I would drop your D value down to D0.1. That will immediately quiet them down, and I found it to have little impact on the performance.

I would also increase your P value. The auto tuning function tried setting my P value down in the 20-ish range like yours and I noticed very poor performance. Just for testing sake I would try a higher number like R100.

The other thing that might help is to post a picture of your tuning graph.

@dc42 VIN fuse. I'll randomly get a communication error with that board and find that it has no power because the fuse is blown. However, it's been a few days and is still good. So I'm not sure what's going on with it.

@usinjin Good catch! Glad you managed to resolve it. All to easy to fall into thinking traps!

Ian

Follow-up, this is basically what I ended up doing. I realize this may not be a good idea in practice, but it does seem to work. I rebuilt the firmware so that in the event of excessive backlash, a warning is issued, and a static value is assigned. Each 1HCL has it's own value it sets.

@nikscha I did--for some reason it didn't like that.

@OwenD Perfect. Should have thought about floor/ceiling funcs. Thank you!

@usinjin said in M42 using variable value is slow/not working well:

Won't G0 set the laser duty cycle to 0%? If so, that is actually pen "down" at full force on my hardware

You could reverse the sense so that 0 means pen up and 1 means down, by inverting the control pin name in the M452 command.

@OwenD Thanks so much. I feel a bit silly that I didn't even think to check the beta releases. For now those will work for development purposes.