Measurement near machine limits

[DaddyBluto]

I have a question for the big brains out there. I have a part that is about as big as the measuring envelope of my machine and I am running into some trouble. I can measure a point at the extreme -Y end by lowering the prehit and retract enough, but I cannot get the machine to measure a circle that is .76" into the machine. I can only measure a little more than half of the circle without getting an error. Are there any settings I can adjust (similar to table clearance)?

Jaime

[Matthew D. Hoedeman]

Try changing the START and END of the circle, if it is at 0 for start and end, try 45 for start and end.

[DaddyBluto]

Tried that Matt. I can measure about 260° of the circle without error. What is confusing me is the fact that this is .76" towards the center of the machine from the point that is at the extreme -Y. The hole is only ø.100". Matt, I know you can figure this one out for me.

[Gord Ashcroft]

Can you access the full diameter by changing the probe angle? The tip vector does not have to be the same as the hole vector

[DaddyBluto]

I could, but I am still confused by the fact that the hole is more than .76" from the limit. Why isn't PC-DMIS allowing it to measure? Thanks for the idea though.

[JamesMannes]

You don't have a "move after" setting for this feature do you (assuming an auto-circle)?

[DaddyBluto]

Yes, but it stops mid-circle or wherever it is closest to the limit. The part is square and level to the machine. It will even take a surface touch -Y of the hole if the angle vector is set that way. This has me stymied.

[Matthew D. Hoedeman]

Tried that Matt. I can measure about 260° of the circle without error. What is confusing me is the fact that this is .76" towards the center of the machine from the point that is at the extreme -Y. The hole is only ø.100". Matt, I know you can figure this one out for me.

Yeah, I know what the problem is, but I have no ideaa how to fix it. Pcdmis is looking at the EXTREME movement locations it could go to BEFORE it even tries to measure the hole, sees that one (or more) of them are outside the envelope and says, "HE!! NO, I AIN'T GONNA MEASURE THAT!"

[bw_bob]

Just throwing something out. Could it have something to do with the zero,zero on your alignment. Can you set the hole as zero & measure ???

[DaddyBluto]

Matt, you have given me an idea. Maybe if I lower my check distance. I'll let you know if it works.

[DaddyBluto]

That was it!!! I had a check distance of 1". If it missed the part it would have traveled outside the envelope. See Matt, I knew you would figure it out.

[Matthew D. Hoedeman]

DANG, Just how crappy are your parts that you need a 1" check distance?

[DaddyBluto]

It was left over from a severely warped part (kinda like me).

[Matthew D. Hoedeman]

Understandable. Don't you just LOVE the way Pcdms now carries EVERYTHING over from the previous program when it used to start FRESH everytime you started a FRESH new program? Ah, progress!

[craiger_ny]

Like setting the search path for part programs. It is wortless now I don't know why it is an option. It just defaults to the last folder a .prg was opened from totally ignoring what you set for the search path. How lame is that? Why even make it an option?

Craig