[kostas1]

Hi,
I need to ask about some issues I met during my last job on my homemade CNC router.

1. I was engraving the 1st attached file (Quick Engrave Letters-Roses.zip) and suddenly it stopped 1-2 minues before the end of the process and mach3 showed the 'Limit Switch Triggered' message without the machine really hitting any limit switch. I pressed 'Reset' button and it continue the engrave process for a while and then again it stopped and showed the same message. I then checked the cables, I checked the motors and I could hardly touched them continuously for 3 secs, and then I pressed 'Reset'. I resume again the process and it managed to get it done.

2. While I was cutting the 2nd file attachment (Profile Borders Roses-Letters End Mill 3mm.txt), when there was a 90 degree turn, the spindle couldn't cut square but cut it with radius. I had motion mode set to 'Constant Velocity' and while my spindle kept going I changed the setting to 'Exact Shop'-> Pressed 'OK' on the fly and then I noticed that the spindle followed a diferrent toolpath than the mach3's toolpath. It was something like failing to resume from where it had stopped. I am not sure if it was my bad but I needed to mention this. I changed the setting on the fly. When entered the General Config menu in Mach3, it stopped the cutting process and it resumed when I hitted 'OK'.

3. Finally, when I was cutting the 3rd attachment (Heart Border-Butterfly Hole Border Profiles.zip), I needed to Feed Hold the process in order to clean the cut area from already cut parts and dust. When I resumed by pressing 'Cycle Start' the motors ran much more slower without changing the feedrate on mach3 screen. I then stopped the process, I loaded the file again and the slow-mode was gone.

[ger21]

1) Noise is triggering your limit switches.

2) Never do anything in mach3 while the machine is running. Especially going into General Config and making changes. Always feedhold and stop before making changes.
You might want to play with the "Stop CV on Angles" setting.

3) No idea on that one.

[kostas1]

1) Noise is triggering your limit switches.

Hi Gerry,
This happened only in that process job.The next day I had the machine working for 2.5 hours and it never happened.
How could I bypass this problem? The reality is that the limit switch cables are together with motor power cables inside the cable chain and when outside of the cable chains, they are bundled with motor power cables using a plastic clip to hold them together. So I assume that this set of 5-6 cables triggers the noise. All the cables I use are shielded though.
I read about capacitors, but is there any software solution to this?

Thanks again.

[ger21]

If there was a lot of vibration, that could also possibly trigger the switches.
The software solution is to increase the debounce setting in General COnfig.
Try setting it to 1000-2000.

[Khalid]

As suggested by Gerry, The debounce settings will definetly resolve your problem.

[kostas1]

If there was a lot of vibration, that could also possibly trigger the switches.
The software solution is to increase the debounce setting in General COnfig.
Try setting it to 1000-2000.

Hmmmmmm, now that you mention vibration, I need to mention that the specific job was quick engraving of small letters at 1500mm/min. I was noticing that the machine was a bit nervous. The 'limit switch triggered' message was showing up in a specific point of machine travel.
But, how could that vibration triggered the limit switch? You need to push the switch's level by your finger quite a bit in order to trigger it.

[Khalid]

This is due to electro-mechanical interference that trigger the switches. Increasing the debounce setting will work for you .

[kostas1]

This is due to electro-mechanical interference that trigger the switches. Increasing the debounce setting will work for you .

Ok thanks, as far as I can remember, there are 2 debounce settings in General Config. Should I put the same value to both fields?
Thanks

[ger21]

Leave the Index debounce at 0

[Khalid]

Furthermore, also check there should be no loose connections of your proximity switches at controller card and near proximity connector.

[kostas1]

Furthermore, also check there should be no loose connections of your proximity switches at controller card and near proximity connector.

Thanks for the info...Should I twist the end/edge switches cables in pairs?