My Z-axis seems to be LOST!

So, I initialize my machine, comes up front to install endmill…good so far. I install a 201 1/4" bit and it goes to the Bitsetter and does its normal thing (2plunges, slow on the second plunge) the I set and zero the Z, Y, And X axis where I want it. I load my file, click start, and to the front for the bit install again, I click resume and on to the bitsetter again and does the double plunge thing. After that, I’m set to start my router to 18K and click start. Here is my problem…as soon as I click start, it goes to the start spot and plunges THRU my darn stock!!! WASSUP WITH THAT?!

How is the origin specified in your file? Top or Bottom?

Where are you specifying it relative to your stock? At the spoilboard surface or on the top of the stock?

Post the .c2d file, generated G-Code, step-by-step notes on how you are securing your stock and setting zero relative to it, and a photo showing an attempt at cutting still in place on the machine and we’ll do our best to work through this with you.

So I got it to act right after shutting everything down, resetting the setting to am Shapeoko XL, it was set to XXL for whatever reason but now it’s not cutting my project to scale with CC. Pictures of that on the way…

If the second plunge is very slow after the bitsetter sends the Z axis to the top of its travel after the first touch of the bit, then I have seen this issue on my machine. Turn the power off and move the X axis by hand fully to the front of your machine. Do the same by taking it towards the back of the machine fully. Then do the same for the Z carriage pushing it first towards the fullest extent in the direction of Y1 and then do the same for the Y2 rail. Finally, do the same with the Z axis carriage. Raise it to its fullest extent after you have lowered it to its fullest extent. Then power on and initialise the CNC as normal and all should be well.

The order you do it in does not seem to be important. It is a way of resetting each of the limit switches. I believe other people have also experienced this phenomenon and the issue may well be software related, given the number of reports which detail some similar happening.

I think you may find this is the issue related to CC expecting all files to be at 96dpi. I did not believe that vectors needed to be specified but I was wrong. CC needs the file at 96dpi and then it will be accurate for the sizes which you have specified in the file.


How do I fix that other than compensating for the size missing in CC?

I draw my designs to size in a drawing program then export them at the correct dpi. If you are drawing the design in CC, there should be no requirement to worry about dpi. Just draw the workpiece at the size you want it to be carved at. If you draw a square of 3 inches in CC, will the square be carved accurately? A circle can also be drawn with a 3 inch diameter to see if it is accurate for size and circular. Try this calibration file from @WillAdams:

What sort of toolpath are you using?

If it’s a No offset contour, then then dimensions will be off by the diameter of the endmill (which looks to be the case).

It was an outside contour cut

But I’m checking now and ensure it’s not and running it again for the 3rd time…need this project done by tomorrow

Have you calibrated for belt stretch?

Tried making a small calibration test in a piece of scrap?

Try this one:

threesquares.c2d (16.1 KB)

What does the square on the right measure when cut?

Another consideration is Climb vs. Conventional Milling and tooling engagement — where possible avoid slotting and add geometry and cut as a pocket (Making vacuum hose adapters and/or Adding geometry to cut as a pocket with a finishing pass ) and consider leaving a roughing clearance and taking a finishing pass.