Hey all,
I was hired recently for IT work and somehow got roped into trying to repair this Tormach PCNC 1100. The company engraves metal and there’s metal shavings everywhere. Checked the oil and it has some, did the pump and it didn’t quickly go back in, based on what I read that is a good thing. The only thing that I can figure is that it has some sort of metal shavings stuck in the movement or possibly one of the ball screws.
Here is a quick video that demonstrates that knocking at 0:16s:
Sounds like a stepper thats skipping steps. There are quite a few things that could cause that, most are the result of some kind of mechanical binding but it could also be electrical.
Easy first step is to switch the stepper drivers between the X and Y motors and see if the problem follows the driver, if so, replace it and you should be done.
If it’s not the driver, step 2 is to remove the x axis stepper and command a move to see if it spins freely. If not, it could be the wiring to the stepper or the stepper itself. Check the wiring for damage or loose connections, and/or replace the stepper motor.
With the motor off, check that you can move the table by hand by turning the lead screw. If not there are a few things to look at. First, loosen the AC bearing and try again. If it’s still tight, try loosening the gib and try again. If it’s still tight, the table is stuck on the dovetail ways and you’ll need to dissassembly further to investigate.
Assuming the machine was running properly until just recently, my guess is an issue with the driver, wiring, or motor as those can work themselves up to a sudden failure. The mechanicals are unlikely to suddenly fail, it’s usually a more gradual increase in problems, unless the machine has been allowed to sit for an extended period of time, then corrosion could come into play.
Thanks Ian,
This is a great starting point for me. From what I was told although highly unlikely…The machine has been leaking oil since they got it, and apparently the cooling spilled as well. I imagine corrosion is definitely at play here
Leaking oil is subjective. Oil can drip from the ballscrews and table ways onto the chip pan, especially the X axis, and especially if a lot of oil is used. It can look like leaking but really it’s just that things are super wet and the excess has to go somewhere.
A coolant spill is also not necessarily a bad thing. My machine has flood with an upgraded pump so coolant goes EVERYWHERE, including out the top of the enclosure at times. Even letting the machine sit between jobs upwards of weeks to a month or two, corrosion has never been an issue for me. Yes, there is some, but it’s pretty minimal. That said, if the coolant mix isn’t rich enough, that could definitely lead to some corrosion.