Touch plate for Shapeoko 3? Also touching-off material?

It appears that using a touch plate for the z-axis on a Shapeoko 3 requires entering a command-line in CarbideMotion, at least based on a video I’ve found on youtube. Is that the best method? I could always program a macro on a key of the keyboard, just want to make sure I’m not making this more difficult than need be.

Also, in reading through the FAQ section I found a “Working with Homing” doc which says (a couple of times) to touch-off the material for the Z-axis. What are they actually suggesting here? Do users lower the bit until it touches the material and won’t go any further?

I’ll tell you what I do now: I have some brass setup bars. I’ll use a 1/2" (12.7-MM) bar and I will lower the Z-axis until the bit is about 8 or 10-MM from the workpiece. With my setup bar on my material and pressed against the bit, I slowly start raising the bit until my setup bar is able to slip under the bit.

How do you guys set your Z?

90% of the time, I use my cutter to probe the material, then click Z0, done. Takes 30 sec. If I am cutting something non conductive, I use a piece of paper, lower the Z until it catches on the paper. I then lower my Z 0.003 (Thickness of my paper), click Z0.

I NEVER, nor have I ever heard of a machinist lowering their Z until the cutter is resting firmly onto the material. Please stop doing this, it is bad for the hard but fragile cutter (Micro chips are common)

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Oh I’m not lowering the cutter into the material, I only asked because the article here said to “touch-off the material” and I wasn’t sure how people are accomplishing that.

The method I use is to keep RAISING the bit until I can slip a 12.7-MM brass bar underneath it. I just apply some pressure against the bit and once the bit is high enough, the bar will slip under and I enter 12.7-MM as my Z. Not perfect, can be tedious and probably not super-accurate.

Tell me more about your paper method, what do you have your jog amount set to, .1-MM or .01-MM?

I’m looking for a less tedious and more precise method, if possible.

This will help:

As I stated, I lower the Z the thickness of the paper 0.003, so I am in inch mode at it’s lowest setting (Ref: 0.001")

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Yep that is helpful (thanks!).

One last Q: When you switch into inches on the jogging screen, does it have any impact on your code or is it just for jogging and the display of coordinates?

I ask because I’m saving my jobs (form Cut2D) in metric and I’m curious if I change to inches on the jogging screen, do I need to save my g-code differently?

Switching to inches I do think would make the touching-off method you describe more practical.

No impact, and no to you question after your last Q. LOL

Enjoy, and make something awesome.

I probe with a clip wire. I put one clip on the bit, the other on a 3.175mm aluminum plate which rests on top of my material. Then probe with the g38 command. When it stops it sets z to 3.175mm which is the offset so that the top of the material is 0 as is required.

On the other hand I rarely use carbide motion so this entire process is automated for me. I do use carbide create from time to time but I prefer other controller software due to these features that carbide motion really lacks.

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Well I’m going to continue looking into the touch plates but using a sheet of paper for touching-off works way better than the brass setup bars I was using, so thanks for that!