Probe Calibration

[xillianto]

Hi, will there be any method of calibrating the probe ?
As not every probe are 100% off shelf, it would be great to calibrate it when probing stock and parts.

[dezsoe]

Could you explain what do you mean by calibrating the probe?

[CL_MotoTech]

The easiest version would be a wear compensation. Maybe probe a known diameter hole, then adjust for a discrepancy via wear comp.

A better version would comp X & Y differently, but it would require the probe be consistently mounted.

[Robertspark]

Suggest using the bore of a large roller bearing as they made to high tolerance and are very hard (less prone to scoring) if you use a branded one YMMV, has worked for me in the past when I used Eric's plugin for mache for probing

http://www.craftycnc.com/probe-it-wizard-mach3/

[eabrust]

Hi Dezsoe,

What CL_MotoTech and Rob describe is what I did in my old Mach3 wizard.

Using a known ring-gauge, the bore was probed at 10 degree increments and a table of 'effective' ball tip diameters was created (ie, values that would produce a perfect measurement on the ring gauge). Later during probing, the probe routine would determine what vector direction machine was traveling in, grab or interpolate the effective ball radius for that direction from the table, then use it to determine 'hit location'. This did also require the probe to be consistently mounted, but the compensation accounted for all the errors at once (backlash, axis calibration error, probe tip deflection/spring load, etc).

A pic on the page Rob links shows the table, which would probably look more meaning full if the diameters were shown to 4 or 5 decimal places instead of 3.

I could dig up some of that VB code if it helped, but it's pretty basic.

PS. I Still wish UCCNC would support G31 with x/y axis combinations I'd still like to try to replicate 'ProbeIt' for UCCNC. I've thought about making use of the 'jog safe probe' ability of UCCNC, then drive the spindle around with jog moves to do probing, but.... that seems iffy

regards,
Eric

[Robertspark]

PS. I Still wish UCCNC would support G31 with x/y axis combinations

+1, given up asking / bumping thread request....
viewtopic.php?f=13&t=63

[dezsoe]

OK, thanks, I see. Then you have to have a precise probe to find the center of the ring before probing the probe. And, because now UCCNC can probe only one axis, it needs only 4 probes. I think, it's really not complicated, I put it on my list.