Centroid Community CNC Support Forum

I feel you pain. Your decription of the jerky behavior and persistant send/resend log errors shure sounds like the pain I endured for months. In my case the machine would reach the point were it actuaslly reversed direction. Thinking it was a communication issue I added double shielded ethernet cable, rewired most of the cabinet, read article on best grounding practive. brought in a scope and expert to look for noise on signal and power supply. .. the list goes on. With each change the thing worked flawlessly for days and weeks ( happy dance) and then the errors started all over when seemingly nothing changed. You may not believe this but what did work was to control the shutdown and startup sequence. When starting up I learned to turn the program on before the board. On shut down I again shut down the program first and the board last.
The day/week variabity that was driving me crazy was in the different start/shutdown sequences I used with out thinking about it. I can not tell you which sequence caused the errors, I only know the one that stoped it. I am basicly a newbe and I am certain the pros will chuckel a bit but I do know what worked and what didn't work on my machine.

Good luck

Thanks for your input. While I am not a newbie CNCwise. I am new to Acorn and servos. They certainly seem to be far more intolerant of noise/interferance. The same machine with steppers did not care at all about noise. The high speed spindle cable was not even shielded and it didn't seem to care. I was under the impression that the control needed to be on first before starting the CNC12 software.
Thanks for chiming in!

recommended start up procedure is to simply power up the Acorn board, wait for Heartbeat and then start CNC12.

Thanks for the clarification.

Thanks to all who have helped me here. I feel as though I have made a huge amount of progress. I was actually cutting parts today even though I know I still have some lingering noise issues. They all stem from the Motor/VFD I believe. My noise issues all disappear when the spindle is off. I have taken every step I know of to eliminate the interference. At this point I suspect the VFD is creating an enormous amount of noise. I have relocated it as far from the existing data lines as is practical. The machine runs but when I check the error log I see I am getting a ton of MPU resend requests. I don't think I am getting them with the spindle off. I have also tested the ethernet connection with all the inputs and outputs unplugged. A basic bench test. No issues.
SO:
Does the length of the power cable leading into the VFD have a bearing on noise? Mine is like 15-18 ft long and it runs under my machine to the outlet. It does run through an EMI filter prior to entering the VFD. My output cable is a shielded VFD cable.
I am thinking of trying a new VFD at this point. Does anyone have a recommendation? I have a 1.7Kw HSD air cooled spindle.
I am powering it with 240V single phase
My existing VFD is a Mitsubishi A800.....I think the 800 stands for the cost:) ...I know this thing is about that much money to buy. It is so complicated. It literally has around 1500 parameters. It's a nightmare for non electrical guys like me. But I need to try something else. Don't know what else to look at at this point.

First, try and replace the cable between the VFD and the motor
https://www.automationdirect.com/adc/sh ... /vfd_cable
Buy 16AWG cable for your application

There are conflicting ways to ground. I follow this one from Belden Wire and Cable:
https://www.belden.com/blog/industrial- ... -vfd-cable

Keep the power cables away from low voltage wiring or make sure they cross at 90 degree angles.
Make sure all grounds in your cabinet go back to the service ground point.

I went back and looked at your photos. I see you have your VFD outside of your cabinet.
Is your signal wire cable shielded?
Is your cable from VFD to the Motor shielded and properly grounded?
Before I threw that VFD away, I would make doubly sure you are following proper shielding and grounding procedures.

Marty

Thanks Marty.
I do in fact have the cable from Automation Direct. Now, did I read that article right? Did it say to ground the shielding at both ends? Everyone who has commented about shielding the VFD wire said to do it at one end only. Which is what I have done. What say you? And yes I have tried very hard to not have the cables near each other except where they have to run through the cable chain together.
By signal wire do you mean the ethernet cable or the signal wires to the clearpath servos? I am using the Centroid shielded cable to the acorn. The teknic data cables are only somewhat shielded according to the Teknic engineer. But they are the recommended cables?

Shinosky wrote: ↑Wed Apr 08, 2020 3:51 pm Thanks Marty.
I do in fact have the cable from Automation Direct. Now, did I read that article right? Did it say to ground the shielding at both ends? Everyone who has commented about shielding the VFD wire said to do it at one end only. Which is what I have done. What say you? And yes I have tried very hard to not have the cables near each other except where they have to run through the cable chain together.
By signal wire do you mean the ethernet cable or the signal wires to the clearpath servos? I am using the Centroid shielded cable to the acorn. The teknic data cables are only somewhat shielded according to the Teknic engineer. But they are the recommended cables?

I follow the Belden recommendation and ground the shield and earth ground at both ends.
A local metal working club member had similar issues, he put a scope on, and saw the noise. Grounded both ends. Problem solved.
Won't hurt for you to try...Ground shield at the motor and ground at the VFD. Make sure you have a good earth ground coming to the VFD and between the VFD and the motor.

In general yes, you only ground one end of the drain wire in a shielded cable.

I meant the cable with your control signals from Acorn to the VFD

Thanks again Marty,
I followed the advice and grounded both ends. I did some minor tests and didn't get any communication errors or faults. I think that may have been it.
Where do I send the money?..... you're a life saver!
I too appreciate the effort of all those here who offer help for free. Centroid should be paying you!

Shinosky wrote: ↑Wed Apr 08, 2020 7:09 pm Thanks again Marty,
I followed the advice and grounded both ends. I did some minor tests and didn't get any communication errors or faults. I think that may have been it.
Where do I send the money?..... you're a life saver!
I too appreciate the effort of all those here who offer help for free. Centroid should be paying you!

Sshhh! Let it loop a program and cut air for a couple hours and then check it...