Hi I'm a newbie.
I have a problem with my home built CNC router bombing out very regularly on a "External E Stop Requested" fault. I'm using Mach3. Can anybody help me sort out this problem PLEASE !!! It stops the router about every couple of minutes.

Many Thanks

Terry

Hi Terry,

One possible cause for this is electrical noise picked up on the limit switch / estop cabling. The easiest first step is to increase the debounce interval (general config page) to 4000 or so and see if this makes any improvement. If it does then fit miniature 0.1uf capacitors from each used switch input to your BoB and GND then return the debounce setting to its previous value.

Tweakie.

Hi Tweakie,

Many thanks for your quick reply.
I have my debounce set at 2000 at the moment. I will lift it to 4000 and try that first. If that doesn't work I'll try the capacictors. I have ferrite beads allover the machine to limit extraneous electricity, but obviously it must be something other than that.

Thanks very much for your suggestions

Regards

Terry

Hi Terry,

Another possible cause is machining vibrations causing the limit switch contacts to bounce. The capacitors should cure this but there is no real substitute for high quality switches if this is the cause.

Tweakie.

We've had issues with the parallel cable between the BOB and the PC picking up noise.  Tried going all the way to 10000 on debounce with no effect at all.  The only solution was to fix the problem causing the noise.  We ended up grounding the PC chassis to the star ground, which is connected to an earth ground rod.

Hi Tweakie,

Once again, many thanks. I will to day if I can buy a better type of limit switch. Thankyou very much for your help. I will let you know how I get on.

Thanks

Terry

Hi rrc1962,

Many thanks for your suggestion. I will certainly try that.

Many Thanks

Terry