[polar8]

Just got myself a Haimer, and it's awesome. Does anyone know if this is a reliable way to indicate the center of a hole?

1. Poition haimer tip in approximate hole center.
2. Jog Y to left side of hole, zero Y.
3. Jog Y to right side of hole, read DRO position, divide by 2 to get true Y zero.
4. Repeat for X.

Here's a rough illustration for the X axis procedure:



This seems like it should work since absolute position doesn't matter. What I'm worried about is the Haimer tip hitting the side of the hole and then deflecting off axis, due to the curved surface.

[WOTDesigns]

It should deflect the same amount in either direction rendering it relatively mute. If you really want to remove it measure X, then move to center, measure Y, then measure X again. I never saw it show more than .0003 error doing X the second time which is better than needed unless you are trying to bore .0002" in which case you should be sweeping with an indicator to get rid of the backlash error and way friction anyways. Try a few times on the same hole and write down the ###s and I bet you will see it matters VERY little. Just hit one axis then the other and rock and roll.

[CountrySmith]

I use the same technique with an edge finder. For greater accuracy repeat the x and y centering with the newly found centers. In my experience, this gets me centered to better than .001".

[jcposada]

Agree with what has been said. In fact the proving routines built into PathPilot (for use with the Tormach probes) work the same way...

[GLCarlson]

Just got myself a Haimer, and it's awesome. Does anyone know if this is a reliable way to indicate the center of a hole?

1. Poition haimer tip in approximate hole center.
2. Jog Y to left side of hole, zero Y.
3. Jog Y to right side of hole, read DRO position, divide by 2 to get true Y zero.
4. Repeat for X.

Here's a rough illustration for the X axis procedure:



This seems like it should work since absolute position doesn't matter. What I'm worried about is the Haimer tip hitting the side of the hole and then deflecting off axis, due to the curved surface.

Yes. That's how it's done. Roughly center the probe first by eyeball. If you want to get rid of the -generally minor- off axis problem, just do it twice. Guy Lautard published a note called "Osborne's Four Steps to Center" or something like that that went into the math in excruciating detail (in one of the MBR's). Essentially, twice is enough, and repeating 3 times is overkill.