VMC600/22 Gross positioning error z b (i have searched for days and applied findings)

Good evening chaps we have a vmc 600 with tnc 370 control we are having following errors

Gross positioning error z c (less common)
Gross positioning error z b (most common)(daily)
processor check error b (less common)

we have noticed that this dose this on a z lift in a rapid but also last week i swapped out the rapids manualy to get the job done and it did it again witch is a pain i have spoken to technical over the phone and they say it could be a hole coast of things but it could be break sticking and maybe lube not getting to where it needs to be (illuminated that today by manually wiring up pump and priming with new oil)

Please note that it starts out fine and at the same point in a program it fails but the program works sometimes it makes a huge bang spindle spools down etc

any help would be appreciated i will go ahead and try clean connectors to the encoders tomorrow also its 3 degrees c in our workshop could that be an issue ?

much appreciated, chris

Processor check errors are often caused by voltage issues. Have you checked the power supply?

i can check tomorrow i presume it has different rails ?

5v ?

12v ?

24v ?

Yes. Normally you will have 5, 12, -12, and 24. Some have 15. It should be labeled somewhere.

Thank you i will try tomorrow although this is the less common error will low voltages cause the others ?

Possibly. If it was a voltage issue I would expect errors in all axes. If all the errors are in Z, you probably do have an encoder or mechanical issue in Z.

Ewlsey's info looks good as guide. I would be fairly concerned about your "3 degrees C in our workshop" conditions. This could easily be a contributing factor to severe drag on spindle due to seals being extremely stiff in that sort of temp (37 degrees F). Perhaps also water condensation in some electronics creating some gremlins.

right update for today ended up running a complicated file lots of all axis movements with not one fault ? admittedly slowed down no rapids... no time to check voltages today besides our workshop multimeter is cheap i will bring the fluke down it also has osilicope feature if needs be but could this just be a cold thing ? condensation on the encoder disk ?


one other thing im not sure if it related but when i post g code from fusion some moved are not smooth jerky you could say on for instance 3d adaptive i have turned on smoothing but no change... someone has mentioned stop bits bing to close together for the old controller no keeping up ? for note i drip feed most programs just due to tiny memory in the machine

I am betting is a supply voltage issue to the machine. I have a TNC 151 that is picky about this and throws the same codes from time to time. The info I am sharing is only too possible help guide you in the right direction or give you some idea.

That said I am running it on a Roto phase with dual 10 hp motors on a residential feed. I am at the end of the line for our street and this line is 60 plus years old. Anyways, I never have these issues during the weekdays while most people are at work. My issues are always on the weekends while many more are at home people. This equals about 4-6 volts lower line voltage than weekdays and this makes all the difference. During the weekdays I can get away with just running one of the 10 motors on the phase converter but to get around the faults on the weekends I have to run both 10 motors. The issue is always during a z+ axis rapied. Like an M19 or tool change.

Also here is another Thread and the Poster also had some of these same issus in the past too. His was a dirty Z axis brake and Servo drive adjustment related. http://www.practicalmachinist.com/vb/cnc-machining/heidenhain-tnc-151-problem-revisited-122012/

thank you for your reply thinking about it we have three phase coming in but when the compressor starts up the internal light dims but only while it starts there is a huge capacitor bank in the back and the feed comes straight from distribution panel i will load up our eltrical system during testing next weekend we have an old late welders etc so i will put in a worse case sonario and make a test file for each axis mainly z ?