I am having an issue with my z axis skipping steps. What is considered safe amperage to run them? Set at .800 now.
Hey Jeff, then there might be another problem. Did you lube the screws? How fast are you running it?
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Cranking up the current should be the last thing you do.
Can you post pictures of your build showing both sizes of the YZ plates from both sides of the machine (4 pictures)?
If you power off your machine and run the Z leadscrews up and down by hand, is there bindingor stiffness at any point of the motion on either side?
Did you run the XZ plates up and down the slides before attaching the stubs to ensure the motion of the slides wasn’t binding?
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Yes, the screws are lubed. Relubed the today. No binding that I can see of feel. Screws turn easily with fingers. When turned off z axis, lowers down on the side the spindle is on. When I run a program the cut keeps getting deeper. It is missing on up steps.
What is a safe rapid speed? I am using carveco maker and whatever the defaults are on the grbl post processor is what I am running. Seems very conservative to me but I am a machinist and used to much faster rapids. I realize this machine is going to be much slower.
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Start with a max speed of 15mm/s, and work your way up from there.
If 15 works fine, then you can keep going faster until you hit an issue. If that is not fast enough you can increase the current a little bit at a time to get the steppers no hotter than 50C preferably 45C or under after a long run.
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Thanks, I will see what I have been running as it is carveco’s default and see if I can figure out how to edit carveco’s post processor. I will post back what I find…
Make sure to check the rapids as well as plunge rates.
Also make sure you do not have the Z stub tension screws in place.
The rapids in up was all I was going to look at. I do have the tension bolts in the z blocks. I will remove them and see if anything changes. Do they create some kind of binding?
They can. Normally you would feel it when you move them up and down manually, but a lot of people miss that. We took them out of the instructions as for most things they are not needed and the adjustment seems to be tripping a lot of people up. The can cause binding down low if you do not have them set right.