My old BP "M" head spindle is a BS #7 I need tooling! or I really would Like to find someone that ould and would rebuild my "M" head and Install a Spindle that is a MT #3 that would be cool as I can get tooling for those yet at a reasonable price. any one out here know anyone or any place to get either done reasonably priced?
Hmmmm.... is that possibly a typo? I won't say you are hoping for something that can't happen, but my "M" head has only MT-2, and I've not seen any reference to MT-3 being available. I don't think the spindle is big enough for an MT-3 to fit in the diameter of the spindle available.
And I don't recall ever having personally seen a threaded MT-3 COLLET, which is required for the drawbar-pull, although I suspect that they do exist.
In their 2001 (note that year!!) catalogue, KBC Tools listed a 3/8" BS-7 end mill holder as KBC # 7-156-010, and under another number a shell mill arbor. Not in the latest, or on the webpage now though. Seems like B&S tapers have run their course.
Just for fun, I did a cad drawing of the B&S-7 laid over an MT-2. WOWWWWEEEEE!!!! Are they CLOSE or what?!?! I never realized that before.
The MT-2 has a taper of 0.59941" per foot (for approximating only, say .6"per), and the B&S-7 is 0.50147 per foot (say .5 per), so you can see that the MT-2 tapers "more" or "faster" than the B&S-7. That's like only 100 thou over 12 inches! Not very much difference. Not sure I would see that difference unless they were laid side by side.
Problem is that the "small end" of the MT-2 is smaller than the small end of a B&S-7, by 28 thou. The B&S-7 is .600 and the MT-2 is .572. So, even though the grip lengths are 2-39/64 for the MT-2, and 2-7/8 for the B&S-7, the point where each exits the socket is .700 for the MT-2 versus about .720 for the B&S-7.
OK....supper interuptus...so I forget what I was doing, but I hope you get the idea.
I think you could redo the spindle you have to an MT-2 with very little trouble. I won't presume to tell you how, but it looks like a couple of ways to do so, either by cutting what you have, or sleeve, or sleeve and cut. It would require a lathe that has a 2-1/2" travel of the compound, and 3" would be better.
I do know that even the MT-2 collets are in a short list of sizes, but they aren't real hard to either make from scratch, or turn from soft centres that flood the market.
B&S #7 tooling comes up on ebay quite often. I just bought a 1/16" collet to complete my set. The seller had a bunch of collets for sale. They went for from .99 to 16.00 each. There's a 3/8" end mill holder for auction now. I'll probably make a boring head and an arbor for an Albrecht chuck or maybe just stick with straight shanks and use a collet. Tom