forum.cncdrive.com

HI,

Is there a way to calibrate the deflection of a 3D probe, by using a ring gauge or something like that?
I converted a Renishaw CMM probe for using on the CNC machine, but it has (a very little) deflection when probing.
I would like to have a way to compensate for it.

Something like this https://youtu.be/MDrLA4ID_wM?t=559 (this is for eding CNC)

Maybe the feature is already here, but I can't find it.

thanks in advance guys!

also, thanx Dezsoe for Fixing the drilling issue I had last year, its working great now!

Greetz, Eddy van der Heide (the Netherlands)

Would you not just set the probe dia offset by that amount , ie if your probe tips measures 3mm and there is a 0.15mm deflection or pretravel before trigger then your actual effective probe dia is 3mm + 0.15mm +0.15mm ( pretravel = and - ) so a total of 3.30mm probe dia.

Hi Thanx for you answer,
I Wish it where that simple.
Do you know how I can measure the deflection? I don't know the exact value.
That's why I would like to have a calibration procedure.
I have a couple of ring gauges, and saw the procedure Eding has, I think it add's a lot of value and precision to the 3D probing process in UCCNC
Thanx

Hi Eddy,

I'll try to find out something, but it will take some time. I keep this thread open to remember.

It is that simple (;-). Take a known diam ring guage. Probe for inside diameter. Known Diam - Probed diameter gives you the probe tip diam accounting for all offset variables. If you need teh probe tip offset (tip radius) then divide by 2.

Just a thought (;-) TP

you can also put a indicator on the probe tip and actually measure the deflection when it triggers , no different from calculating effective probe tip from a known dia ring using the software ( assuming your steps/unit is accurate - if not then the software method is a more accurate approach.

This is a interesting video on pretravel

https://www.youtube.com/watch?v=Qtg6K27h_eI

I don't recall any process more accurate or simpler than teh Ring Guage method.

(;-) TP

Would love for the calibration to be entered aswell into uccnc development.

But is there anyone who could make a macro for this perhaps ? To measure travel between 2 contact points perhaps ? Atleast we get a number that we can enter manually to correct the probe tip diameter

Have you seen the probe screen?