Centroid Community CNC Support Forum

I wired all the home switches to inputs 1-3. Same thing.. random over heat fault.

I can't wrap my head around that problem.
I bet the motors aren't hot....
Love to hear what the solution is....

No the motors aren't hot and either are the drives. When I look at the motor monitoring... whatever axis I'm looking at...once the servo backs off the home position and stops you can see the torque value is very high. Close to the 550-650 range. It will stay in that range and then fault out. If I just step off that home position and command the axis to go the other direction the torque value drops substantially and it will not fault. It's like the servo is fighting to stay in that position but there is nothing trying to keep it since x and y arent moving. I even manually tripped the switches when the machine was homing but I tripped them when the machine was in the center of its travel not close to the home positions so see if the position of the table/saddle/head had any thing different. Same thing. Over heat faults.

The motors do this not connected to the screws?

I'm going to try this first thing in the morning.

Raceman17 wrote: ↑Fri Apr 10, 2020 12:43 am I'm going to try this first thing in the morning.

Sounds good. You can simulate the home switches by taking a wire from input 1 and COM and touch them together to simulate the contact closures. Use HomeAll, it will be easier.

So today first thing a disconnected the shaft couplers from the ball screws and manually tripped the homing switches. Of course no fault. Then I messed around with a bunch of setting to see if anything would change and there wasnt. Still over heat faults. I did however manage to break the tuning cable during my troubleshooting today by tripping over the wire. If course it ripped the usb end right off the circuit board so it's not repairable. I ordered another one from cnc4pc. Hopefully it will be here in a few days. During testing it was noted that if the machine homed and I immediately backed off each axis by .050 inches there was no faults. So at the end of the day today I disconnected the cooing fan to just see what was happening. As the machines were homing and hit the switches the motors would start to hum and it would trip out. Turn the sound up if you watch the video.

It just sounds like the driver is giving more juice to keep it in the position. I think tomorrow I am going to start with a fresh slate and try again from scratch and do only one axis and see if I can get it to fault out. Is there anything particular I should be paying attention to in the wiring detail or how specific wires should or shouldnt be ran? What about the mounting plate. Should I use wood or something metallic? I've just been using stranded copper wire 18ga for low voltage stuff and 14ga for main power as well.
As for settings I have been using 2000 and 2000 for my gear number and line encoder. 8000 steps per rev on wizard with a pulse frequency of 400000khz. Also the driver fault time is set to 1 millisecond.

Raceman17 wrote:So today first thing a disconnected the shaft couplers from the ball screws and manually tripped the homing switches. Of course no fault. Then I messed around with a bunch of setting to see if anything would change and there wasnt. Still over heat faults.

As that is phrased, I cannot tell whether you still got overheat faults while you had the shaft couplers disconnected; or if you still got overheat faults only after you reconnected them.

No overheat when the couplers were disconnected. I hooked them back up and the over heat faults were random again on the axis after homing sequence

My guess is that the drives have to continually go full current forward then full current reverse repeatedly trying to maintain position with those coarse pitch screws. Hence the overheat fault.