Inventables Community Forum

Z-Axis Position Loss

Recently purchased the Shapeoko 2 and finally got it put together. While testing a 3d model, the Z-axis began losing its position and would gradually cut deeper into the material without being commanded. The g-code sender program says the machine is still at its original position though it is definitely not. By the time the code finishes, my project is ruined and my wasteboard is cut clear through. It's like the Z-axis is losing its zero position.

Anyone else had this problem? What is the fix?

A couple things to check:

  1. Your hex file on the Arduino may be corrupted. You can re flash the Arduino and see if that fixes it.

  2. Is the offset consistent? Is it possible the units are set wrong?

I'll add to this one other possibility: if the bit is loose in the collet it can slip down farther and farther while cutting. Are you seeing the cut get deeper and deeper while the spindle seems to stay in the same place? Or is the spindle and z axis actually lowering? One easy way to check is to watch the flexible coupling between the z-axis stepper motor and the threaded rod. If it is turning, then there is something in the g-code that is telling the z-axis to descend. If it isn't turning, then the spindle itself is actually at the same position (and the g-code sender is correct), but the bit itself is probably slipping deeper and deeper.

I had this issue happen to me a few times especially when using the generic rotary tool that comes with the S2. It is hard to tighten the collet on those spindles.

Thanks for your reply. I am more mechanical by nature after years of aviation maintenance so the electronics are a bit of a mystery, or magicland if you will. That being said, could you give some pointer on how to re flash the Arduino, please?

We posted a YouTube video that explains how to re flash the Arduino.

I had this exact problem, my feed rate was too fast for the Z-Axis to keep up with the X and Y axis.. The higher feed rate was fine for X and Y but the Z Axis kept going deeper and deeper because it wasn't fast enough to raise itself. I lowered the feed rates and cut again and it 3D cut fine.

So I followed the video tutorial. It took a little while to get it right but it's working now. But now I have new problems. The scale is off. I created a 10 inch by 10 inch example drawing and the carving was approximately 2.5 by 2.5 inches. I have checked numerous places to ensure my drawing/project dimensions were correct. How can I adjust the scale?

That sounds like the machine was set to mm and the drawing is inches. You need to be sure gcode is telling the machine to use the correct value. G20=inches; G21=mm

Hi…I need desperate help on my z axis going deeper and deeper while doing 3d finishing cut.
I keep ruinning my project.
Does anyone have an idea how i can correct this situation.

I had an issue like this one time when running the original z axis that came with the xcarve. I had inventables and vectric both scratching their heads and I was pulling my hair out, stii growing back.

If you are running the original “z” check the itty bitty little grub setscrews on the acme rod pulley, mine had worked loose. you might want to consider changing them out with hex head cap screws and using blue loctite when reassembling it.