[erikh206]

Hi,

My Tree J-425 with Dynapath 40 controller runs good but with a snag. Every time you hit cycle start, The machine does not go to the same place twice. Machining a part that already has cut features will find the new cuts off location. Changing x and y offsets to correct the problem is of no use as the machine is always off location again. Can someone tell me where to look for a fix? Location can be off by .005 in any direction. A part machined in one set-up is better but not perfect.

Thanks!,

Erik

[underthetire]

Probably needs new drive belts, but are you talking after power up/restart or just part to part.

[erikh206]

Hi,
This would be part to part I'm concerned with. In the morning, X homes where it should but Y can be off by .100.... I always re-dial x and y on start-up. I know I shouldn't have to but until I get it figured out..... Z is always perfect.

Thanks!

[underthetire]

Move the Y switch about .02" to fix that. You simply are triggering home right at the reference mark on the encoder, so it is hit and miss right now. Your initial problem sounds like worn out timing belts on the axis. Make sure your getting plenty of lube on the ways, and hit the zerk fittings on the ballscrew bearing housings with EP2 grease.

[erikh206]

Wow, never would have thought about the belts..... Anything special I should know before I order some? Tension? The ways and ball screw bearings are lubed good, everything is dripping all over the floor! I will bump the Y stop and test out the home also.

[underthetire]

Just don't over tighten the belts, other than that nothing special. 10 minute job really.

[erikh206]

OK, the belts are on order. I bumped the stop .02 and it still missed the mark by about .1 when I powered up the 2nd time. Third and fourth power ups homed in the proper place. Bumped it another .01 and tried several more homing routines. So far so good. Will keep trying it until I'm confident it finds the proper home every time.

[erikh206]

OK, the belts are on and so far the repeating looks much better. Mr Under-the-tire, I tried to reply to you but your message box is full. Can I PM you some other way?

Thanks,

Erik