Backbores

nowherenearadoublec · Posted: Mon Oct 06, 2003 9:11 am Post subject:

Does anyone know what size of tapered reamer is used to make the backbore?
Alan

Tootsall · Heavyweight Member Joined: 05 May 2002 Posts: 2952

Which backbore? There are many different ones; varying in terms of the "rate of taper" as well as the "shape". Some have a barrel shape (quickly expanding and then the expansion slowing down), some are the reverse (being more "tight" until they flare out almost like a bell flare) and some are just "straight sided" with a constant rate of expansion. There is no single, universal "backbore".

nowherenearadoublec · Posted: Mon Oct 06, 2003 1:07 pm Post subject:

What tool company makes the reamers tho. I understand that many bbs are different but usually a taper reamer matches a taper pin which is very different! For example who makes Schilkes and Callets reamers?
Alan

Tootsall · Heavyweight Member Joined: 05 May 2002 Posts: 2952

Call 'em and ask. I would be surprised if they tell you since that sort of thing is likely to be a closely held secret; get your hands on one of their reamers and you've pretty much got part of their "secret ingredient".

_Japle · Posted: Tue Oct 07, 2003 5:39 am Post subject:

The reamer I used (see the thread "Adventures in mouthpiece design") was made for auto-body work. It was very rough. I had to smooth out the primary lines and resharpen it. That reamer produces an extremely open backbore.
The reamers used by the manufacturers are all custom made. I'd look for a good machine-tool equipment retailer in your area. Figure out the shape of the reamer you're looking for and ask them.

John
Cape Canaveral