joint limit error

I have recently been getting a Joint 0 joint 1 Joint 2 error limit message when cutting. I can air cut just fine. but seems like when it engages with any resistance I get the message. I can restart and it will go a little further and get the error messages again. Haven't changed any thing.

I built the machine about a year ago and have put a lot of hours on it. never had any problem. Just cranked it up after a couple of months and cut 3 or 4 gears and then the problem started and has progressively gotten worse.

Any ideas would be appreciated.

Pop

Hi

If it is a Joint 0, 1, 2 LIMIT (switch) error that would mean that you probably have all your limit switches chained together?

If you disconnect your limit switches from the BOB and comment out the references to them in your .hal file, does it all run properly?

Then replace the connections in the .hal file and put a link across the terminals on the BOB that connect to the limits, does it run OK then?

The problem then is either in the wiring / switches or possibly in noise in the wiring.

I had a problem with a small mill with a very 'dirty' far eastern DC motor.
It was forever tripping the limit switches, no matter how much screening and earthing I tried.

Eventually I resolved it simply by using a 12v feed through the limit switches from a separate supply, which powered a small 12v relay. The contacts were connected to the BOB, giving a NC
situation with all limit switches closed.

The increased voltage and indirect switching completely cured the problem.

regards

Another possible solution if it is 'noise' that is causing your problems, is to use a debounce component.

My big mill has a 3 phase spindle motor which sometimes caused limit switch errors when running, because the VFD and all the other electrics shared a common mains feed.

debounce will prevent a momentary spike or drop from registering, without impeding a normal switch opening event.

.hal file snippets

regards

ArcEye

Thanks for the info. I've read else where that noise could be the problem. So I'll give this a try. Hope it solves the problem.

POP

the hint you gave for the problem .... being you cranked it up ! , and before that it was fine .
certainly makes for interference of some kind , or your power supply is incapable of supplying enough amps etc .

are your limit switches or low voltage cables shielded ?
also check for sound joints in cables plugs etc

cncbasher

no they are not shielded

one thing you said that I was wondering about- amps - I recently put in a new ac and heating unit and we live in the country. Our voltage will vary from 100 to 130. I have a 12v power supply that I use on my telescope and it will vary from 8 to 12v causing the dc motor to slow dramatically. could that cause the problem?

guys,
thanks for the help I tried them all and it seems that the issue is related to my fluctuating voltage. It has settled out and the seems to be operating fine. The last time I tested it, I started the router and then started the program--worked fine-cut not problems. Next, I started an air cut the started the router. As soon as I started the router I got all 3 axes errors. Then restarted the router and started the program on a gear cut -- no problems -- cut fine.

Again thanks for the time and thoughts.

Pop

shielded cables will certainly help .

Regarding your 12v power supply if it's dropping by a large amount , i'd get a better quality power supply with the capability of more Amps and with some reasonable smoothing caps fitted (Wall wart types are nasty, and don't have decent smoothing )
it wont stop the drop totally , but it will help make it more stable and less prone to problems due to your unstable supply voltage