NM-135 spindle problem

[keithmcelhinney]

I posted this in the Novakon forum but since it is an issue with Mach3 as well I figured I would post it here too. Please forgive me for the mutliple post..

OK guys I am a complete newbie at this stuff and am slowly learning. I purchased a NM-135 and picked it up in Canada. Great experience and great people. The only disappointment was not getting to me Khai since he was out on a sales call. Packed it up got it home and set it up. I have had a couple of problems, but I think it helped me learn more so I will take it. Now I have one problem that I can't seem to figure out. I can not get the spindle to stay spinning. It will sometimes spin up almost to speed and shut down and others times it will just start and then stop almost immediately. It throws the "external estop requested" error. I am using the xml that I got with the machine. I actually had to reverse the x and z and change the parallel port but that is pretty much all I have done. The spindle will spin manually from the CD-300 no problem. Anybody have any ideas?

Thanks in advance!
-Keith

[Torchhead]

The key here is that you are getting "external e-stop requested". In short that means MACH has seen an e-stop event on at least the e-stop input pin and/or a limit input. That is turning off your outputs and shutting down the VFD. It's noise getting into the inputs. Most likely suspect is the VFD which is very noisy. Start by making sure none of the input wires (like from limits or an external e-stop) are runnign in the same bundle as the AC input to the VFD or it's output wires to the motor. Keep as much distance between anything on the VFD and the table electronics. Not knowing the input circuit, they might be using, it's hard to say how much noise suppression is on the lines and if they have any other e-stop inputs like safety switches, etc. One of the valid reasons for using opto isolated inputs for the PC is to break noise from the common grounds. The poor high freq response of a normal Opto helps to suppress HF spikes as well. Most breakout/interface cards include added RFI and EMI suppression.

If you think it's a limit just disable the limits temporaryly in MACH and see if the problem goes away.


You can increase the Input DeBounce number in the General Config section of mach. You can go as high as 4000 unless you want to use in input for high speed signals (encoders, etc). If that still fails to do it then consider getting some large Ferrite cores and taking several wraps of the AC lines at the VFD. Use one core for the AC lines in and separate cores for each leg of 3P out to the motor.


I won't hurt to make sure the metal part of the machine is grounded to a good local earth ground

TOM Caudle
www.CandCNC.com
Totally Modular CNC Electronics