USA source for 5C MT2 adapter?

I did some looking online and found a place in europe with a couple of different ones for 13 and 19 euros. Couldn't find any available in the USA.

I'm thinking I could take one of the MT2 horizontal mill arbors I just bought, permanently attach* the taper end to a 5C MT2 adapter, mill a key slot in the adapter for a drive collar and have the straight end ground (or cut it myself if it's not hardened) to the same taper as the outboard end of a Hardinge TM/UM arbor.

*Slow set super glue and tighten the holding bolt really firmly, with more super glue on its threads.

Hardinge makes one: shophardinge.co.uk - Ecommerce Web Site At their price, though, you might as well pay shipping from Europe.

I suspect the Hardinge 5c adapter is hardened; making it hard to mill a keyway for a drive collar. Do like the general idea, though, of cobbling together an arbor for your Hardinge mill. If your 2MT arbor isn't too hard, perhaps you could turn it round then silver solder it into a small 5C face plate (machined to be a drive collar??) as one possible expedient to just making the whole thing from scratch. You might also consider boring the faceplate near 2MT and finishing it with a reamer, then the silver solder, braze, Loctite, etc. .

I have to say I made a 1" arbor for my TM with a straight shank and a 5c collet. Never has worked as well as the OEM arbor. One problem is that tightening the arbor nut enough to hold a cutter tends to pull the arbor out of the collet. I can get it to work with a collet stop and a shaft collar next to the collet as well as not tightening down the arbor nut until the arbor support is tight. Kind of a pain though and someday I do plan to make or acquire an OEM style arbor to replace it with.

Teryk

One wonders WTH Hardinge was thinking when they decided 5C would be good for a horizontal mill spindle instead of a #30 taper. (And 4C for the vertical head? There's what, two other machine tool models ever made that use that size?)

I have one 7/8" arbor that is apparently shop made, has no key cut for a drive collar. I got some other arbors with MT2 and R8 shanks at an auction, just for the spacers. After some pondering I figured I could use a drawbolt in the MT2 end's threaded hole to permanently attach the arbor to a 5C to MT2 adaptor.

reduction sleeve 5C-MT2 with tightening screw M10x 30 mm-RC5CMK2Z
reduction sleeve 5C-MT2-RC5CMK2

Should be able to do the same with the R8 arbors if there's a readily available 5C to R8 adapter.

The TM and UM aren't enormous Cincinnati mills that weigh thousands of pounds. Some super glue or loc-tite along with being pulled into the MT2 or R8 adapter really tight with a drawbolt, plus making drive collars to engage the spindle lugs, should work fine at the power level of the UM.

Not saying in the big world it was the best idea. But Hardinge probably figured the 5c system was a fair spindle option for the size & HP so that the user could use all the other Hardinge 5c tooling his shop would no doubt be equipped with for all his other hardinge machines. 4c was probably used on more machines than you are thinking, though why not just use 5c both places on the mill is a poser. At the time the mill was designed, a lot of Hardinge lathes were still being shipped with 4c for shops that did smaller dia work. So while perhaps 5c & 4c were not logical as far as ideal drive system, it made economic sense for shops that bought Hardinge. While 4c machines were still common, it saved the factory from having to re-design the legacy system vertical head. These mills go way back, to when they were essentially conversion kits for 4c & 5c bench lathes. The parts changed and improved, but the thinking apparently did not.

I tend to think that among a few key reasons that Hardinge was so successful is that they constantly simplified their product, but improved materials, design features, and ergonomics (usually), and then charged more for it anyway. The evolution of the toolroom lathe is an illustration. The original quick change swing lathe was fairly complex in both parts count and machining. The T-10/TL was somewhat simpler, the HLV simpler yet. The -h was about the same as the HLV, but wider bed and some other improvements for rigidity and durability.

smt