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General Mach Discussion / external e stop request false signal

« on: September 16, 2013, 01:03:25 PM »

Hi all,

I'm having an intermittent problem with false e stops at random occurrences during jobs. 'external e-stop' warning is displayed in mach 3, which I can then reset. It is not due to limits, it's just the external e stop. I'm using a gecko g540 and a smoothstepper. I have the e-stop pin of the gecko (pin 10) connected to a rocker switch on my enclosure, with the second terminal wired directly to my power supply negative. I just use this like an enable switch and I have a separate e stop on the enclosure power input. Would this false e stop come from a false low on pin 10 through noise? It is very sporadic, happened twice today and 3 times about 2 weeks ago, both times it repeats and then for days I have no trouble. I have just set the mach 3 input debounce to 2000 to help deal with noise. Could the 'external e stop requested' come from anything else other than this input? Is it possible to record the input states over time to identify if it is noise on this input? Would a small inline capacitor between my rocker switch and pin 10 work/help? I have run a break in wizard for 4 hours today, with debounce at 0, with no problems. It's so frustrating when problems are not regularly reproducible. When this occurred earlier today, I reset the estop and restarted the job from the line of G code I was on pressing 'start from here', only this started the toolpath from the beginning but from the location the spindle was in....wasted a nice plank of french oak (why couldn't it have been mdf!!!). Is there a way to continue a toolpath from the position of the stall/fault?

Any help with this would be very much appreciated, I'm really tearing my hair out!

2

General Mach Discussion / lumps & bumps

« on: May 30, 2013, 01:38:55 PM »

I've just been making my first cuts on my recently finished CNC router. I cut a small table top earlier today, and had 3 small bumps in a profile cut (g-code attached). The timber is maple, I did 15 x 1.5mm passes and each pass had the bump in the same place. I'm confident there are no lost steps as the rest of the geometry was smooth. There is no uniformity to where these bumps are in relation to the rest of the geomtery, and I would expect if there was mechanical culprit for these bumps to be elsewhere in the toolpath. I've taken a close look at the g-code toolpath and this seems to be fine.  I don't think there is any backlash, and the bump positions don't seem to be on curves. Any insight would be much appreciated!