Calibration/qualification of Disc Styli

[McGyver]

Hi all,

I have just ordered a 25 dia. by 2.5 thick Disk Styli for a new project coming up soon and would like to know how to calibrate/qualify it, can anyone please help?

Thanx in advance,

[J Temmen]

If it's in you tool library then just build it and calibrate it as usual. I would suggest that you use a more common buildup to find the sphere if it has moved i.e 2x20mm. If its not in the library you can do it manually with at least 2 rows of hits, one just below and one just above the equator of the sphere.

[craiger_ny]

What J Temmen said. Best way is to have your artifact in a position that another tip has been calibrated in. Then tell it the artifact has not moved. If it has moved hit the "Manual" radio button to qualify and take hits above and below the equator of the artifact but not on top of it like a conventional ruby stylus. I'd go back and do it DCC after that. Better safe than sory and you need all that is possible on your side with the discs as they can be tricky accuracy wise.

[McGyver]

Thanx guys,

I thought it would be more complicated.

[John Kugler]

Not to rain on anyone's parade, but you must be careful of the number of hits you take for your calibration. If you are like most of us on the board, you probably take 15 to 25 hits on the cal sphere to calibrate a probe. This is too many for a disk probe. I had this issue come up some time ago. I did everything I could to get it to work and it would constantly error out. I called tech support, who then called Wilcox, who then called me back. Turns out, that the software cannot handle more than 12 hits for a disk probe. No one knows why this is, just that it does. I was told to leave it at five and that would work. Now I was at a different angle than 0, 0, but that shouldn't matter.

Just a little heads up.....good luck.

[McGyver]

Calibrate/qualify disk styli

I have received my disk probe this morning, I have tried to calibrate it as you said but keep on getting a message " Take hit 1 of 6 on SPHERE ID ID???? When I measure on the sphere I get the following message, "Measured probe diameter exceeds the limits T1A0B0" .
The probe also has a small pin fitted protruding 0.5mm on both sides from the thickness, what is the purpose of this pin and where should it be facing (Mine is facing Y-minus).

Could someone please explain step by step how to calibrate the disk probe?

[Tested]

The message your getting "Measured probe diameter exceeds the limits T1A0B0" is due to a setting that you can adjust. It is a warning that you setup yourself "your company" it does not mean that your calibration is bad the probe may in fact read bigger or smaller than stated due to the length and/or touch force. The pins on either side are sometimes used to check a distance or take a touch point be very leary of any points you take with these.

[#2#]

The easiest way to calibrate your disc...

Setup your calibration sphere and clamp it so it won't move. Take an existing ball stylus and calibrate A0B0 on this probe. Then change to the disc and tell pcdmis that the sphere has not moved. It will not prompt you for manual hits and should dcc calibrate without any problems. Assuming of course that in the measure window dcc is selected.

[#2#]

Oh, and the ID thing is refering to the IDentification of the sphere not the Inside Diameter.

[rangerboat72]

Oh, and the ID thing is refering to the IDentification of the sphere not the Inside Diameter.

If you stretch the pop-up window with your mouse it might also help understand what PC-DMIS is asking you to do on manual hits...

SORRY GOODLUCK, I JUST HAD TO DO IT (I'm extremely bored) . . .

[than_357]

Disc styli only measure in a narrow range around the OD of the disk, so ignore the pin (I believe it's just for clearance or to make operators ask "what's the pin for?").

I run the probe qual. like any other probe. Important that you have "Default Mode" selected under Calibration Mode in the measurement window. Aside from that.... Check that whatever head you're using will allow for the extra mass dangling on the end.

Tom H>

[rangerboat72]

Hey look Craig, I got someone to jump on it too...

[dtmtim]

On the same subject - I have a job where it looks like I'm going to have to make my own disc stylus. Geometry will be approx .030" thick X .400" diameter. Can you tell me how to qualify a home made disc?

Thanks!

t.

[#2#]

On the same subject - I have a job where it looks like I'm going to have to make my own disc stylus. Geometry will be approx .030" thick X .400" diameter. Can you tell me how to qualify a home made disc?

Thanks!

t.

Can you make the length and diameter a number which is very close to a spherical probe tip already in your drop down menu? If so, just use the spherical probe tip when you define the probe and set the start and end angles for your calibration accordingly. The little picture of the probe won't look correct but that doesn't matter.

[dtmtim]

I should be able to pick a size that will fit in the undercut grooves that I have to inspect that resembles a standard sphere. Thanks for the tip - I'm glad I asked before I made the disc.

t.