Probe Calibration for run-out

[atestani]

Is there a way to use MSM to adjust the run-out on a touch probe?

[DaveCVI]

MSM (and Mach) assume that the probe tip is concentric with the spindle axis. So, MSM want to see the probe mechanically adjusted for concentricity.
I don't know of any generic way to handle probe tip run out in mach.
The issue is that mach does probe tip compensation internally - so when a probe touches at the surface of the tip, mach knows the tip sphere diameter and calculates the trigger point to be at the tip center - and reports that point as the trigger coordinate. The only info that we can give mach is diameter - there is no way to tell mach about run out (or any probe tip geometry other than "sphere").

In theory it is possible to do this outside of mach - but only for those probes where the probe direction is pre-known - and even then it's a bit of a mess as the contact point is not always at a point on the probe tip that is the intersection of the direction of travel and it's perpendicular plane.

Dave

[atestani]

Thanks, Dave

I wasn't clear in my question, sorry. I am looking for a utility, script, screen, etc. to assist in minimizing the probe's run-out. Tormach has this in their version of Mach3 but I am looking for a way to do it in MSM on my machine.

I wonder if the round hole/pocket probe capability in MSM can be adapted to make measurements with a known bore or ring gage at a x,y zeroed position and advise what screw to adjust. It would be an iterative process but *very* useful.

What do you think?

[DaveCVI]

Oh, sorry, I mis0understood what you wanted.
I'm willing to think about this, particularly if more people also want the features (speak up readers if that is the case).
One concern that comes to mind is what mechanism different probes use for adjustment - it would be unattractive from a MSM support standpoint to to have a different adjustment routines for each probe.model.

Can you point me to the documentation for what Tormach does? I'd like to look that over.

Dave

[atestani]

I think it would be fine to support a "generic" probe, the type with an insulated mandrel with 3 metal spokes at 120 degrees apart that contact metal balls. The adjustable ones have 3 cap screws for adjustment and 3 set screws for locking the setting in place. I would think you could require inputs of the bore diameter of the ring gage or reference tool being used and the pitch of the adjustment screws. You may need to "measure" or require the user to input the diameter of the bolt circle of the adjustment screws that moves the bottom plate as the adjustments are made. You could also assume the ring gage is perfectly centered in X&Y by other means.

Attached is the screen in Tormach's version of Mach3 which I was referred to when I contacted Tormach for parts following a crash of my Tormach Passive Probe. This is why I am looking for a way to easily calibrate the probe. I tried it with a dial indicator and while I got sort of close, it is a painful process!

There is a trial version of Tormach's Mach3 here:
http://www.tormach.com/downloads.html
and the Manual for a PCNC1100 here:
http://www.tormach.com/tormach_product_manuals.html (UM10087 page 118)

I have those downloads but have not been able to run the Tormach version of Mach3 since it has a "hard-coded" XML setup file so it is a manual process to convert it to my own I/O pins.

I have some other "procedures" for doing this manually if you are interested. Let me know on that or anything else you need and I will get them to you.

Thanks for considering this.

Al

[derek]

(speak up readers if that is the case).

Dave

Derek speaking up:)
I have the Tormach probe and would like something like this.

Thanks

[SkyMoCo]

Any progress?

I'm another Tormach owner running MSM and this is one feature that would be useful.

[DaveCVI]

Thanks for the additional expression of desire for this feature.

There has been some progress - alas, of the negative type... I'm pretty sure that the MSM probing library is the largest Mach3 script around. I seem to have run up against a bug in the script editor / compiler. The bug manifests itself by refusing to compile the library. No error messages, no complaints, it just does not save the .mcc file.
Until I can find a way around this bug (artsoft is apparently no longer fixing bugs in Mach 3) I can't add any feature to the lib - as any change that increases the code size seem to hit this bug.

Dave

Any progress?

I'm another Tormach owner running MSM and this is one feature that would be useful.

[tmostad]

What I did is launch the Tormach config and adjust my probe then close it and launch MSM. It would be nice if MSM had this feature but it something that you should do rarely enough that having to launch a different config isn't a really big deal.

So Dave given the state of Mach3, have you given any further thought on working in Mach4? This would of course require that Mach4 actually works someday but I am guessing that it actually might.