Small Shank To Regular Shank Modification

[Dan Schultz]

I know, I know... the most common way to overcome having a small receiver on a horn is to get a small shank mouthpiece or change the receiver... both of which I am capable of doing.

However Has anyone experimented with the idea of opening up a small shank receiver to accept a regular shank mouthpiece? I spoke with Gary and Cliff Ferree this afternoon about why they don't offer a reamer for tubas like the ones they make for cornets, trumpets, and baritones. We're talking about a Morse taper here (.050" per inch taper), but the common size 1 reamer is too small and the size 2 is too big. What would be required would be a reamer with a big end of about .600" diameter and a small end of about .463" diameter (about 2.75" long flutes). The insertion difference between a small shank and a regular shank mouthpiece is about 1 inch or about .050" in diameter.

Has anyone else done this or given it any thought?

[Rick Denney]

The insertion difference between a small shank and a regular shank mouthpiece is about 1 inch or about .050" in diameter.

Has anyone else done this or given it any thought?

Doug Elliott has a reamer that he told me he had to make. It was the only tool that could have solved the problem on my York Master--the factory had neglected to ream the proper taper in the receiver in the first place. Previous owners had been using small-shank mouthpieces, never noticing that they were a bit wobbly.

.05" isn't much of a cut, but if the cut extends down to the leadpipe, it might cut through it. It would depend on how the leadpipe is attached to the receiver, I suppose. The YM had a receiver tube that was fitted over the leadpipe. Doug only cut about an inch of taper, which was enough to fit a standard mouthpiece. He then shaved down the shank on the mouthpiece I bought from him to make a perfect fit.

I would probably spring for a reamer like that, because it would also be good for the final truing of a receiver that had been whacked and straightened.

Rick "who thinks it might be good for modifying old instruments to work with new mouthpiece without losing the old look or finish" Denney

[Chuck(G)]

Dan, you want a Jarno No. 5 taper reamer. Morse taper varies by size, with only the No. 1 having the 0.050" taper, while Jarno taper keeps the taper at 0.050" across the entire range of sizes.

I'm also sure you've discovered that the breakover in sizes of a Morse 1 and 2 doesn't include the diameters found on tuba mouthpiece shanks.

A Jarno 5 usually has a small end of about 0.500" and a large end of about 0.650"---perfect for tuba mouthpieces.

Oh yeah--Jarno tapers overlap in siameters, so if the No. 5 was too big, you could start with a No. 4 (whose diameter runs between 0.400 and 0.531).

Piece of cake.

[Dan Schultz]

Dan, you want a Jarno No. 5 taper reamer.

Nope! I've already looked into the Jarno taper reamers. The taper is right, but they have the same problem as the Morse taper reamers... The size that would be effective to make the small to regular shank transition would be an 'in between' size. The reamer would need to have a body of 2.75" long and run from .600dia down to .463dia. The major effective diameter on a regular shank receive (from what I can see on my mouthpieces) is about .578dia.
I spoke to Cliff Ferree on Wednesday about this and he can custom-make whatever I want for what I think is a reasonable price (about $60). I email Gary Ferree last night with the above dimensions and asked for a firm price.

[Chuck(G)]

Nope! I've already looked into the Jarno taper reamers. The taper is right, but they have the same problem as the Morse taper reamers... The size that would be effective to make the small to regular shank transition would be an 'in between' size. The reamer would need to have a body of 2.75" long and run from .600dia down to .463dia. The major effective diameter on a regular shank receive (from what I can see on my mouthpieces) is about .578dia.
I spoke to Cliff Ferree on Wednesday about this and he can custom-make whatever I want for what I think is a reasonable price (about $60). I email Gary Ferree last night with the above dimensions and asked for a firm price.

Dan, I've got to be missing something here, so please bear with me and try to explain things in words of few syllables.

First off, I'm assuming that because the tapered shank portions of the two types of mouthpieces aren't the same length, yoiu simply want the large/standard shank variety to be inserted to exactly the same depth (i.e. distance from the shank end to the leadpipe end) in the receiver.

Okay, I take my trusty DW2 (besson small shank) and my bass-tbone-shank Bach 6 1/2AL mouthpieces and measure the outside diameter of the small end of the shank: 0.500 +/- 0.005. So I'll want the large shank mouthpeice to insert into the receiver where the inside diameter is now about 0.500".

Now I grab a PT-48 and a Bach 18 and measure the same part on their larger shanks: 0.525" for the Bach and 0.535" for the PT-48, which is what I'd expect, since the PT is a "European shank".

So, the job would seem to boil down to enlarging the point at which the receiver is 0.500" to 0.525" or maybe a bit larger if you're going to use European shank mouthpieces.

So, at first blush, it would seem that a Jarno 5 with a small end of 0.500 would be just the ticket.

But hang on--any reamer you''re going to pass down the receiver is going to cut a taper the entire length of the reamer's flutes. Ideally, we'd just want"a "step" at the point of insertion and not affect the way the leadpipe fits into the receiver, right? Otherwise, we end up cutting a taper the entire length of the receiver and wind up having to shim the leadpipe to get it to fit again (since we're not changing that, right?).

So why not this approach: Take a Jarno 5 and at around 0.520"-0.525" or so, cut ithe small end off (or grind it down, your choice) and then sharpen the ends of the flutes so that the reamer now functions as a mill at that point to cut our "step" into the receiver. The leadpipe insertion area remains unaffected and we have a recevier that fits our standard-shank mouthpieces.

Comments?

[Dan Schultz]

So why not this approach: Take a Jarno 5 and at around 0.520"-0.525" or so, cut ithe small end off (or grind it down, your choice) and then sharpen the ends of the flutes so that the reamer now functions as a mill at that point to cut our "step" into the receiver. The leadpipe insertion area remains unaffected and we have a recevier that fits our standard-shank mouthpieces.

Comments?

OK. I think I will do two things.... I'll get a Jarno #5 but leave it intact. Then... I'll 'rough out' the receiver with a 1/2" hand reamer or even a 1/2" end mill until it just touches the lead pipe. Then I can plunge the Jarno #5 until it bottoms out against the lead pipe. It may require a little 'trial and error', but I think this can be perfected.

Think this is a plan?

EDIT.... Neither Enco or McMaster-Carr carry Jarno reamers. I checked with an outfit on the web called 'Newmans' and they quoted me a price of 'about' $200 for a #5. YIKES I think I'll keep talking to Ferree's instead of trying to find a cheap solution!

[Chuck(G)]

OK. I think I will do two things.... I'll get a Jarno #5 but leave it intact. Then... I'll 'rough out' the receiver with a 1/2" hand reamer or even a 1/2" end mill until it just touches the lead pipe. Then I can plunge the Jarno #5 until it bottoms out against the lead pipe. It may require a little 'trial and error', but I think this can be perfected.

Think this is a plan?

I think so--and if the Jarno 5 (straight flute, finishing reamer, I hope) doesn't work for you, I'll buy it from you.

[Dan Schultz]

[if the Jarno 5 doesn't work for you, I'll buy it from you.

Reread my earlier edited post

[Chuck(G)]

[if the Jarno 5 doesn't work for you, I'll buy it from you.

Reread my earlier edited post

I'll try some of the surplus tool dealers and let you know what I find.

[Dan Schultz]

[if the Jarno 5 doesn't work for you, I'll buy it from you.

Reread my earlier edited post

I'll try some of the surplus tool dealers and let you know what I find.

OK. I have another observations for you to ponder: I just looked through a box of odd standard receivers. Mouthpieces that measure .518 on the small end go all the way in to the step where the leadpipe goes into. The c'bore for the leadpipe (on most of them) measures .588" dia. So.... If the leadpipe has a .030" wall thickness, the step (or mismatch) inside the receiver is going to be created by by the mouthpiece. If the reamer actually got into a bit of the mouthpipe what would it hurt? I'm thinking it might even be closer to a smooth transition as long as there was enough material. We're only talking about .010" or so. What I'm speaking of is to eliminate the 'gap' altogether by allowing the mouthpiece to extend slightly into the leadpipe. Trying to think out loud here

[Chuck(G)]

Maybe--but the variation in mouthpiece shank sizes for tuba is truly amazing, so there's already a potental for mismatch. But then again, the Dillon AGR exploits this.

Not much help, huh?

[Dan Schultz]

Maybe--but the variation in mouthpiece shank sizes for tuba is truly amazing, so there's already a potental for mismatch.

Yeah, I know. I have perhaps 30 mouthpieces and the shank sizes are all over the place. I've got some that engage the regular receiver only 1/2" and others that go in more than an inch . Not much standardization in this business. Y'know... it's odd, but I've found the plastic MP's to be the most consistant