Ok, I've got a question

[gus]

I have been dealing with the error in the Z axis "WRONG REFERENCE POINT"
on my TNC 145 R2C3 for some time. It will occur if i do not shut the machine down at a particular spot, + or - probably 1/2 a motor revolution right below the trip dog. Fine, I can deal with it, a real annoyance when you EMO the machine 4 inches down, but its ok. It is not intermittent, it will happen any time the machine is not stopped in the particular spot it likes.

Here's the problem, my Interact has started doing it! Slightly different, the interact will move all the way up from the bottom before erroring, so at least I don't have to manually crank the z up.
On the R2C3:
I tried changing the PC board that contains the optical receivers, no difference. I recently changed the trip dog switch, thinking that one of the two contacts must be not correct[both NO and NC contacts are used] No difference, and the new switches have the terminals reversed so it was not as easy as it should have been.

My real logical problem is that the machine, by my way of thinking, should not be looking at all for the reference points until the trip dog is hit, thus my disappointment that the trip dog was not the solution. If the light source were weak, then all the encoder functions should be compromised.

I have owned this machine exactly 15 years now, and this problem is going on probably 2 years. The only time I have been in the Z axis is a while back, before this occurred, but not exactly, I got a "Z AXIS DEFECTIVE" flashing error, and it was a dust shield in the encoder end had come loose and was flopping around in there. Took the lid off, took it out and end of that issue.

ON the Interact:
The problem is intermittent, and since restarting the machine fixes it, it is not bugging me, but I worry that i will get worse. At least it acts as I would expect, not erroring until the trip dog switches



Ideas?

[Dirky]

Hi Gus......as you know,....I am NO expert yet on these measuring systems....but as you also know I am getting many hours of hands on experience.. In the process of setting up my series 2 interact 2, I did see a behavior that sounds VERY similar to what you are describing. It was with the Z axis getting a "wrong ref error"...a "defective measuring system "error and at one point also the "Z axis defective error prompt". I think it was you or George that suggested a faulty encoder...or wire....since I did replace the encoder wire in question I was confident that was not the problem but I pulled the encoder cap anyway....simply routed the wires around the inside of the cap in the opposite direction and ...more important I believe I fiddled with the little plug and its poor lock system in order to get a more positive contact at the encoder plug....didnt think it amounted to much of a change....but...the unit has not given another Z axis fault of ANY type since....it may simply have been due to resistance built up due to oxidization on the pins of the encoder plug....Oh yes and the other detail....I blew in across the optics lens as well....perhaps that did it ???what the hell give it a try....good luck....Bug ya later