tapered reamer & lathe biz

[Tim Jackson]

I know I have seen this on the site before but I can't find it.
What size tapered reamer do I need for cutting the back bore of a tuba mouthpiece?
and... what company would offer one in american steel. I guess I mean something that would last!

My lathe is finally-fondly coming out a 25 year storage... 101.07301 Craftsman 6" 1946

Also, after looking around for stock,(2" solid brass rod) I don't see how folks can afford to fiddle around with making one-offs. Anywhere to buy a few cut-offs? Maybe even stainless? (what kind?)

I noticed there are different types of brass offered on various sites. Any guidance would be greatly appreciated. Just want to have a little fun merging my hobbies.

MERRY CHRISTMAS to ALL!
Tim

[Doug Elliott]

A 6" Craftsman does not have enough power or stability to safely work on 2" stock. I'm not even going to encourage you to try, because I did that myself. It's really not safe.

And don't even think about stainless.

[Donn]

Aluminum? My hobby machinist friend was crazy about aluminum. The stuff gives me the willies, but I guess with the right finish it might be OK - there is at least one mouthpiece maker doing it.

[opus37]

You have enough power to turn wood and not much more. Don't bother with a reamer, just drill it out, unless your going into production and that is a crowded market.

[royjohn]

The small Craftsman bench lathe I have in storage around here somewhere is belt driven with a separate motor. I think mine has a 1/4 hp motor, but is there any reason the motor couldn't be beefed up to handle bigger stock? Would the gears or keyways strip out or ???

[Doug Elliott]

The real problem isn't lack or power, it's lack of stability. It's just too small.

[Ken Herrick]

A point nobody has touched on is a major part of your question; what tapered reamer to use. I am pretty sure you will not find a suitable one available commercially, ie even an engineering supplier will not have what you need. MAYBE, though not likely, a current mp maker would sell you a used one. Decades ago Schilke would sell me one as I had worked for them. In any case it would quite possibly not be what you want.

Your craftsman might do the job but would need to be very well set up and well run. Any slop in the carriage or cross slide, or vibration would cause chatter giving a very poor, rough finish. It would not be impossible to do what you want, especially if you use sharp tooling and do a lot of the cutting and shaping using a series of good files.

Now if that lathe was say, a nine inch South Bend from that era, in good condition, you would have a better chance of success if you had good tooling, skill, and patience. Making one, as in one of a kind, is achievable. Making two the very same is a lot harder as you need to make cutter tooling. "Mass' produced models would now generally be made using CNC lathes. Lots of $$$$ there.

[Doug Elliott]

It's not impossible to work on a Craftsman 6", I did it in my first year of experimenting, but I definitely don't recommend it. You can only make tiny cuts and it is dangerous to work on anything a big as a tuba mouthpiece. There are no commercially available reamers that will work. I made my own.

[Ken Herrick]

What Doug has said is very good advice. He knows, because he has been there and done it and does it very well.

[royjohn]

I think there's a market for those old Craftsmans...I've seen some restored ones sold for some pretty good money...so sell the Craftsman and look around for an old, somewhat larger Atlas or South Bend or similar.

[Greenbenches]

2" brass should not be too awful if you remember to use negative rake tools. That includes flattening the flutes on your drills. Otherwise, the tool will self feed in the brass and crash. The little lathe should stall but it may damage something. If I remember it has a lot of aluminum parts and gears. Chatter can be dealt with by lighter cuts and slowing the spindle. Keep your tools and chuck ups as short as possible and take small cuts.
The lathe likely cannot drive the reamer needed, even in back gear. Maybe, if you carefully drill steps the length. I've always overdone at least one of the steps.
The reamer can be made by turning an oil hardening (O-1) drill rod to the plug shape of the backbone then cutting away half plus a thousanth or so and hardening and polishing.
The outer shank taper is best done with a taper attachment but I've done them with the compound slide set at the correct angle. Tuba shanks are rather long.
I would say that you should leave stainless alone until you have at least a strong 10" lathe. 12 or 13" better.
Have a template for the cup and nibble with a rounder boring bar until you are close. Brass blends and polishes easy with emory.
OnLine Metals or McMaster Carr are my favorite for materials. MSC Supply for tools and drills.