Shapeoko 2 - Z steps per mm was badly off and VCarve

Creative Arts
#1

Z Steps; For an unknown length of time the steps per mm on the Z axis of the Shapeoko has been incorrect. The symptom is depth of cut being much less than specified; e.g. specify 15mm and receive actually 9mm of cut dept. I’ve fixed this and added known good settings to the Wiki page

VCarve: If you’re using VCarve to generate gcode for the Shapeoko please use the post-procesor labeled “Shapeoko Fixed MM” - it’s been tweaked so the initial retract is 5mm above Z start. The regular Shapeoko post-processor was using the XH variable for this and sometimes the movement was so large it exceeded the Z-Max on the Shapeoko, causing the spindle motor to hit the top of the carriage :frowning:

P.S. 2 classes in early June are on the Calendar.

Thanks!

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#2

Good Evening Sir,

I found this old post about the z-axis for shapeoko, but I’m not sure how related it is to my issue. In the class, you mentioned that the z axis can become off in the firmware. I believe this has happened. I have to set my cut depth to double what is really is to get proper results.

cutting a .25" piece of MDF has to be set to .55 in easel.

Do you know how to fix it?

#3

Yes, setting $102 is more than likely out of whack. The correct setting is on the wiki https://dallasmakerspace.org/wiki/Shapeoko_2 - do you know how to set it?

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#4

i was able to get my project done yesterday regardless, but next time I’m at the space I can take a look. I’m not sure how to fix that, but I doubt it’s something a quick google can’t fix.

#5

I don’t think you can do it in easel, you’d need universal g-code sender or similar.

The process though is easy;

  1. make sure nothing else is using the USB serial connection to the Shapeoko GRBL
  2. Connect a utility, like Universal G-code sender, that allows you to issue raw commands
  3. Send “$$” to dump settings and look for $102.
  4. If $102 doesn’t match the wiki (320) then send “$102=320” to reset it
  5. Disconnect and carry on!

Edit: I’m still trying to figure out what’s causing this. Can you check your machine setup for me before doing anything else? Make sure you’re not setup for ACME Rod

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#6

Sadly easel doesn’t let you see your settings, launching the config just shows them blank and let’s you pick again, so I recall setting it up correctly, but it’s always possible. next time I cut something I’ll reset from scratch and see.