Making or acquiring a 26mm end mill holder?

"DeepDiver" wrote in news:37I6f.462$ snipped-for-privacy@typhoon.sonic.net:

Contact these folks, bet they have one. May not be cheap though.

Lyndex-Nikken, Inc.

Thanks for the tip.

I should have mentioned that economy is a factor. Not just because I don't want to spend a lot of money, but also because I'll probably have to shorten the end mill holder in order to get one of the set screw positions to line up with one of the locking holes in the boring head shank. In other words, I don't want to be cutting on a new, $50+ brand-name end mill holder.

- Michael

I don't have any experience with this (you asked for thoughts or advice); but I'd think you could bore it on a lathe with a carbide tipped boring tool; taking very, very light cuts.

I'd probably take the collet to an auto machine shop and have them hone it to the desired size with an abrasive hone. You'll want to put the collet in a holder and put some brass in the slots so that it doesn't compress.

-- Why do penguins walk so far to get to their nesting grounds?

Actually, I was referring to a solid end mill holder, not an R8 collet. Not that I have anything against R8 collets, it's just that I don't think a collet would be a good choice for this particular application.

But it might not be a bad idea to take the 1" end mill holder to an auto machine shop for honing to 26mm.

- Michael

It'd be a lot easier to turn the shank down to 1" to fit an end mill holder, or 3/4" to fit an R8 collet, than to bore the holder. The shank is likely hardened, but probably not too hard to turn with carbide. Depending on the material it may work harden, so I wouldn't count on being able to remove small increments on the diameter.

Worst case, if you make a mess, is to have it ground to the desired size.

Ned Simmons

I realize that's an option. But I am opposed to cutting or grinding the shank on this beautiful precision tool, not so much for practical reasons, than on principle. The way I look at it, an adapter is a consumable part that is subject to change over time (as a tool migrates from machine to machine, or as the adapter wears). So it makes more sense to me to modify the adapter than it does to modify the tool.

- Michael

Lyndex-Nikken has R8 1.25 end mill holders, standard and stub. How about getting one and making a bushing? Maybe you can get a different shank for the head, unless it is integral. I would probably turn it down myself.

michael

Thanks Michael. Actually, that's an excellent idea. I had already considered making adapter bushings to fit some English-sized boring bars into the 16mm bar holding holes in this boring head, but I hadn't considered making a bushing for the shank. I don't know why I overlooked this.

And there are a number of sources of 1.25" and 1.5" end mill holders, including Bison (a brand I prefer for their combination of both precision and economy). I'll probably use a 1.5" end mill holder so the bushing has more "meat". That way, I can add set screws to match the locking holes in the existing shank, as well as a Weldon flat to lock the assembly in the end mill holder.

Yes it is integral. The body and shank are precision ground from a solid billet. (It's a really nice boring head -- another reason why I don't want to turn down the shank.)

Had it not been integral, then I would have made a custom shank from an R8 arbor (as I did for another metric boring head I have that does have a threaded hole to accept a shank).

- Michael

Yes, the ER40 does go to 26mm. But I like Michael's bushing idea better for adapting the shank to a larger end mill holder.

As for the Ebay source linked above...

Unfortunately, "800watt" is one of the few sellers on Ebay who carries a wide range of inexpensive new import tooling (like the Morse taper collets I've been looking for). But his feedback rating is questionable, with lots of negatives for non-delivery after payment and no replies to email. And he pads his sales with his S&H fees. From what I understand, his idea of combining shipping is to just knock one or two dollars off the per item S&H fee.

I myself have tried contacting him and have not been impressed with his communication (more specifically, his lack thereof). I prefer to avoid Ebay sellers like that.

I don't know the guy from Adam but a 97.7% positive feedback on 46,400 transactions is not to shabby especially on a $ 25 item. Mind you, I am not endorsing anyone and I was not trying to steer you to this particular seller, just "the means" of doing what you wanted to get done.

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DeepDiver wrote: