[TurboStep]

Have you checked the tool table to verify the diameter of the tip for you Haimler? They sell 0.2 inch tips and 4 mm tips, as well as other sizes. The diff between 0.2" as 4 mm is almost exactly 40 thou.
Terry

I figured Terry was on to it. It sounded to me like a 4mm tip in an imperial probe (even if your probe is off center it won't have any effect on the measurement you're attempting).
That was, until you wrote this:

FWIW, at the start of this, I checked the tool holders for runout (it was very small), and mic'd the shaft of both endmills (within ~.0005 of 1/2"), yet the difference in their cutting width seems much greater than that (~.03)...?

Even if you meant ~.003 that would be too much. If you did really mean 0.03 then you must have a huge amount of slop somewhere (very loose gibs perhaps?).
Step

[Hirudin]

... even if your probe is off center it won't have any effect on the measurement you're attempting
...

Oh yeah, you're right.

[Gerry Kmack]

When I got into the shop yesterday, I installed my Haimer & checked for concentricity. It was waaay off. So far that I couldn't correct it with the adjustment screws. (?). So I removed the Haimer from the spindle & removed it from its holder. Nothing seemed obviously wrong, so I carefully cleaned all the mating parts with alcohol, reinstalled everything, and... Boom! Now the concentricity was out by just over a thou. With a bit of tweaking of the adjustment screws I got it to well under 1/2 a thou. Much better. I ran the same test that started this whole thread off and... It now reads very close to the caliper measurement - within (~.0002). Awesome.
Thanks to all who responded, and especially those who suggested checking the Haimer calibration.
After this experience, I'm considering re-installing all of my tooling - cleaning first, then establishing my own check list to certify the accuracy & actual cutting characteristics of each tool.... Does anyone out there do this?
Gerry Kmack

[tmarks11]

well glad you found you had a problem before you scrapped a bunch of parts because your zero was off.

[CadRhino]

No

When I got into the shop yesterday, I installed my Haimer & checked for concentricity. It was waaay off. So far that I couldn't correct it with the adjustment screws. (?). So I removed the Haimer from the spindle & removed it from its holder. Nothing seemed obviously wrong, so I carefully cleaned all the mating parts with alcohol, reinstalled everything, and... Boom! Now the concentricity was out by just over a thou. With a bit of tweaking of the adjustment screws I got it to well under 1/2 a thou. Much better. I ran the same test that started this whole thread off and... It now reads very close to the caliper measurement - within (~.0002). Awesome.
Thanks to all who responded, and especially those who suggested checking the Haimer calibration.
After this experience, I'm considering re-installing all of my tooling - cleaning first, then establishing my own check list to certify the accuracy & actual cutting characteristics of each tool.... Does anyone out there do this?
Gerry Kmack

[pickled]

When I got into the shop yesterday, I installed my Haimer & checked for concentricity. It was waaay off. So far that I couldn't correct it with the adjustment screws. (?). So I removed the Haimer from the spindle & removed it from its holder. Nothing seemed obviously wrong, so I carefully cleaned all the mating parts with alcohol, reinstalled everything, and... Boom! Now the concentricity was out by just over a thou. With a bit of tweaking of the adjustment screws I got it to well under 1/2 a thou. Much better. I ran the same test that started this whole thread off and... It now reads very close to the caliper measurement - within (~.0002). Awesome.
Thanks to all who responded, and especially those who suggested checking the Haimer calibration.
After this experience, I'm considering re-installing all of my tooling - cleaning first, then establishing my own check list to certify the accuracy & actual cutting characteristics of each tool.... Does anyone out there do this?
Gerry Kmack

Gerry,

I have a light commissioning procedure here. What I do is clean the cutters with an acetone wipe then measure my end mills flute to flute on a surface plate just for a sanity check. You will find that most quality cutters may be slightly undersized out of the gate, but well within their established specification. I then install them in the respective holder (ER or set screw) and put them in my machine where I tighten the draw bar down by hand-quite snug. I'll indicate the run out and perform a sanity check. Probably 90% of the time everything checks out great. Sometimes, however, I'll find that I have a concentric error and it is usually driven by a wayward small chip hidden in the holder/collet. I typically do not go beyond this level of due diligence because the returns are diminishing. Back in the day I had a test part program that I would run before I did a production run. Basically I would machine a 1"x 1/2" boss out of some 6061 square stock then measure it for obvious errors. I found so few deviations that I abandoned the practice after 6 months. That was in 2011. I will be using the check part program again shortly though because I just sent 20 carbide end mills off to be re-sharpened by a new service provider. Trust but verify!

[Uman]

This subject inspired me to inspect my Haimer and perform a functional check on it. The tip was slowly cycled across its entire range by hand and I noticed just after the zero center position, the movement required more force to continue, repeatably. I cycled the tip several times and this extra resistance at near zero center soon worked its way out. I suspect since the tip movement rarely goes past zero center (except for that one time), the movement past this point does not get exercised. Since I have not broken a tip in a long while, the Haimer does not get fully exercised. This will now be part of my setup procedure. Thanks for bringing this subject up.

-uman

[Jabs1542]

"This subject inspired me to inspect my Haimer and perform a functional check on it. The tip was slowly cycled across its entire range by hand and I noticed just after the zero center position, the movement required more force to continue, repeatably. I cycled the tip several times and this extra resistance at near zero center soon worked its way out. I suspect since the tip movement rarely goes past zero center (except for that one time), the movement past this point does not get exercised. Since I have not broken a tip in a long while, the Haimer does not get fully exercised. This will now be part of my setup procedure. Thanks for bringing this subject up."


Haimer calisthenics before working