My machine has been working fine for the last 4 months. I have done many carves with no problems. Occasionally the machine would not complete the homing sequence. But most times it got pretty close to tripping the switches and a second home command did the trick.
Having a bit of down time, I set out to “fix” the problem by changing the wires and using 2 conductor shielded cable. I got 22 gauge wire.
After re-wiring I tried the machine and much to my surprise I got the same behavior as I was getting with the twisted pair. I read on the Forum about how to connect the shied on the cable properly and I although I thought I had it right, I could perhaps do better. Let me explain: After the wiring was installed I connected the shield of the cable to the ground on the gshield, This is negative of the 24V power supply.
Reading on the Forum I decided that I should really connect the shield on the cable to “real” ground, that is the green/yellow wire coming from the wall plug to the power supply.
Now, all I get is a couple of bursts of movement, in the right direction on Z first, then on X and Y. Not enough movement to reach the homing switches. UGCS seems to think the homing sequence completed as it shows an OK status and the red banner goes away.
I have checked the switches monitoring the gshield status, after setting $10=19, and there is no noise on any of the homing switches and when tripped manually they show the proper status, 001 for X, 010 for Y and 100 for Z. If I disconnect the ground to shield connection I do see noise from the switches.
Since the switches appear to be working and the signal is clean (and the behavior is exactly the same every time) I thought the gshield is fine as it can see the signals changing.
I have re-flashed the arduino and even tried a second one, no change. I hope this is not a gshield problem.
As a side note, I can move all axis in all directions with no hesitation at all. Homing switches remain noiseless when moving the gantry in all directions.
I don’t know what else to try and would appreciate any and all assistance.