[FFWD]

Hey guys. This problem has plagued me for the past week or so...and I have officially hit a brick wall.

I have a multi fixture setup on the table. Hasn't moved for years. Machine is a 1990 Fadal 4020 with CNC88 controller driven by HSMWorks.

I'll use the edgefinder to dial in my fixture X and Y offsets on fixture numbers 1 and 2. Start making the parts. Everything is fine from start to finish.

Power the machine down for the night...come back next day...put new parts in the 1 and 2 fixtures...and start cutting. I find that my Y axis will be off anywhere from .020 to .040 off every single time on both fixtures.

X and Z are always just fine.

However, it makes all the features of the part just fine. Bolt hole spacing, slot widths, and what not are just as they should be. Deadnuts and consistent between parts. Just program zero shifts on me in the Y direction on both these stinkin' fixtures.

This problem only exists on fixture #1 and #2. Anywhere else on the table I have other fixtures, there are no issues.

At the recommendation of my tech (and Fadal USA), I even swapped axis controller cards. Swapped X with Y. Nothing changed. Problem still there.

Another test was to re-set my offsets, turn the machine off, and re-check offsets when I power the machine back up after a few minutes or so. Offsets will be fine and match my previous measurements. Only happens when the machine is left off for the night.

I think at one time, it also changed after only one cycle...I can't remember. I've done so much testing and measuring, I don't know which end is up anymore.

Of course, I did the obvious and made sure nothing wonky was going on with my Y stops on those particular fixtures. Solid as a rock.

Bottomline here....it has a mind of its own. I don't think there is a pattern to this. If there is, I haven't found it.

Any ideas on what's going on here? This is driving me absolute nuts chasing this issue down. I think I've only made two accurate, good parts during the same cycle since this problem reared.

Please save me from jumping off a cliff. If you need more info to help nail this problem, I'll be happy to oblige.

Thanks bunches everyone!

[DareBee]

Maybe need to install security cameras

[FFWD]

Maybe need to install security cameras

lol Now that was funny!

I have done more tests on this issue last night.

I can now confirm it's not just leaving the machine off overnight that will bring back an incorrect Y axis...it can also be while the machine is running that the Y axis changes on me. For example, I ran a slotting op within the cycle, paused the program, measure, and it was fine. Finished the part. Started part #2, ran the entire cycle all the way through and the Y will got back "off".

You can also re-zero my fixture, start the same slotting op and it will slot incorrectly on the Y axis. Go back and check the fixture, and it will indeed be off. Crazy! Yes...it can happen that quickly.

So I can't just leave the machine on and/or re-zero every time I power up. This will not rectify the problem or even work around it. Interesting theory though.

Encoders and mini steps? Don't believe so as this problem is only on two fixtures...not on all the others. In other words, isolated...not global.

The only thing left that I can think of at this point is maybe there is a software glitch in the EPROM chips within the axis controller card? I might have swapped the cards, but I also kept the chips with their respective slots.

I still don't know...