Interact positioning error question

[Mike Woo]

Hi. I have a Bridgeport Interact 1 with a TNC145 box. When i turn the machine off and restart it the next day the 0,0 position i set from the previous day has moved 2mm or so on the Y axis. This has caught me out a couple of times with miserable results! Is there a cure? Thanks all.

[gus]

mine used to do it by exactly .100, I think what it is is if the trip dog is too close to the reference mark on the encoder it may miss it and be off by one half a revolution

the timing was always random, but the distance was always the same.

If one were to rotate the servo without the belt attached and put it back maybe it would fix it, but I never actually tried it on mine. You have to redefine the parameters for y axis travel afterwards. I ended up changing out the y motor completely, because I dropped it while cleaning out some coolant that got in it, and I don't think it does it anymore, but I also have a 151 on the machine now.

[Daninwyoming]

I had trouble with my Interact 1 Mk2 Heidenhain 151 doing the same thing, except it was on the X axis. I found the reference dog switch was not functioning. Changed out the reference switch and cured the problem.