Machine not keeping point placement

[jgovan]

To all:

I am using version 4.0 and I am having issues. I am using a DEA GAMMA machine. We just recently had the machine serviced and all was well with the results after the tech left our facility. He did mention that the PH9 was going out. He said that due to an error light being lit on the controll unit while the machine was being used. He said that the error light shouldn't be lit. I am aware that they don't support this head anymore as well. So I am forced to either get a refurbished one or upgrade my PH unit.

The issue that I am having is after I do my alignment( plane, 2 lines, construct a point), my DCC alignment points are off. I have checked the code and everything is correct. I have also had the code verified by another cmm operator at another facility.

I am taking the points for my DCC plane in the same area as my manual plane. The points are shifting in the X plus axis approximately 5 mm. I typically cut everything off before I leave. On yesterday, the points were shifting in the X minus axis approximately 8 mm. I programmed the part fine on Monday and ran another before I left with no issues. On Tuesday when I returned the points shifted in the X minus. I redid the program and ran another part afterwards fine. I cut my computer off, but left the controll unit on. When I arrived this morning, the points shifted in the X plus direction.

Any suggestions and/or reccommendations would be greatly appreciated.
Does any of you feel that the PH9 may be the issue??

thanks

[Matthew D. Hoedeman]

Are you re-aligning the fixture BEFORE you try to measure anything AFTER you re-home the machine? Your exact XYZ machine zero point will NOT be the same from HOME to HOME. It could be that is the problem. Re-do the MANUAL alignment as well and see if it is all right then.

When you re-align, DO NOT expect to see your inspection points fall back to the same XYZ locations that they were before (the ACTUALS, not the THEO's, the THEO's should stay the same), the actuals will stay in space in relation to the OLD home position, so if the home position changed by 8mm in X, then the point will appear 'shifted' that same 8mm in X.

[JamesMannes]

To all:

I am using version 4.0 and I am having issues. I am using a DEA GAMMA machine. We just recently had the machine serviced and all was well with the results after the tech left our facility. He did mention that the PH9 was going out. He said that due to an error light being lit on the controll unit while the machine was being used. He said that the error light shouldn't be lit. I am aware that they don't support this head anymore as well. So I am forced to either get a refurbished one or upgrade my PH unit.

The issue that I am having is after I do my alignment( plane, 2 lines, construct a point), my DCC alignment points are off. I have checked the code and everything is correct. I have also had the code verified by another cmm operator at another facility.

I am taking the points for my DCC plane in the same area as my manual plane. The points are shifting in the X plus axis approximately 5 mm. I typically cut everything off before I leave. On yesterday, the points were shifting in the X minus axis approximately 8 mm. I programmed the part fine on Monday and ran another before I left with no issues. On Tuesday when I returned the points shifted in the X minus. I redid the program and ran another part afterwards fine. I cut my computer off, but left the controll unit on. When I arrived this morning, the points shifted in the X plus direction.

Any suggestions and/or reccommendations would be greatly appreciated.
Does any of you feel that the PH9 may be the issue??

thanks

Yes and no. First off. I wouldn't use 4.0 if it were forced upon me. I used it for about 20 minutes before knowing it was junk. Can you upgrade to 4.2? If so Iwould suggest this to start with.

As far as the PH9 goes you will have to run some tests on it to see if it repeatable. I don't think the head would cause you to be out by 5mm one way one day and 8mm the other the next, maybe though. Start with a fresh qual, saying "YES" the probe has moved so that you have to tke a hit on the spher etc etc. And make a little program with a couple of tip chnages in it measuring some known piece. Do you have an unused, claibrated ring gage? That should do it.

[jgovan]

Thanks for your input.
I was doing a manual alignment after each part is placed on the fixture.
I'm not too sure what the issue is but I just cut the machine off until the afternoon and rebooted everything.
It seemed to work itself out but we plan on getting someone to look at the machine.

[Matthew D. Hoedeman]

Thanks for your input.
I was doing a manual alignment after each part is placed on the fixture.
I'm not too sure what the issue is but I just cut the machine off until the afternoon and rebooted everything.
It seemed to work itself out but we plan on getting someone to look at the machine.

Does your program ALSO do a DCC alignment?

I never, ever check anything without a DCC alignment.

[jgovan]

Yes. That is where I noticed that my points were not the same. My manual points were fine because I took them. But when it went t do the DCC alignment, it went wild.