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Mouthpiece shank straightener

Posted: Wed Feb 10, 2021 8:57 am
by MrHCinDE
I had a small accident with a mouthpiece which ended up with the end of the shaft becoming out of round. It no longer fit properly in the leadpipe and with the current situation I wasn‘t keen to visit a tech. for one small job. Anyway, after looking round for a bit, I found this from Böhm tools.
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It has two parts: one to carefully round the end of the shaft, the other to correct for any small over-expansion caused by the rounding.

It worked great on my mouthpiece, it‘s a perfect fit once again.

Does anyone use a similar method? If not, how do you do it?

Re: Mouthpiece shank straightener

Posted: Wed Feb 10, 2021 9:20 am
by BGuttman
I have a similar tool. It's a long tapered shaft (fits the inside taper of most mouthpieces) with different bushings for different mouthpiece sizes. It also comes with a little hammer to pound out the dents, although I have a similar hammer from a shop project in High School so I didn't buy the hammer. I just have large shank and small shank bushings.

Re: Mouthpiece shank straightener

Posted: Wed Feb 10, 2021 11:30 am
by Burgerbob
Instrument Innovations sells a kit with all shank size collars, a truing tool, and a mallet. I've saved probably 10 mouthpieces with it.

Re: Mouthpiece shank straightener

Posted: Wed Feb 10, 2021 11:58 am
by Kingfan
I like that the Bohm kit has a tool to correct over-expansion. There are lots of tools out there that can fix the dents, but few that can fix the fix.

Re: Mouthpiece shank straightener

Posted: Wed Feb 10, 2021 12:17 pm
by Doug Elliott
I plan on offering a kit like that soon.

Re: Mouthpiece shank straightener

Posted: Wed Feb 10, 2021 12:21 pm
by BGuttman
The Instrument Innovations kit (which is what I have too) collars will fix the overexpansion as well.

Re: Mouthpiece shank straightener

Posted: Wed Feb 10, 2021 12:48 pm
by ithinknot
The collar kits are great for 'band director emergencies', and for correcting others' repairs.

If you really want to do this near-undetectably, you need several different tapered mandrels, tapping down the high spots with the mouthpiece free and the mandrel in a vice, checking with a straightedge as you go. In this case the collars are still useful in the final stages.

A single T-handled taper that's steep enough to begin opening up a flattened shank can return the edge to round, but won't fully correct the deformation further up the shank; the collars resist the force being transferred to the undamaged side, but you're still proportionally over-flaring the edge and undercorrecting elsewhere, unless the tool exactly matches the backbore in question.

Re: Mouthpiece shank straightener

Posted: Wed Feb 10, 2021 2:13 pm
by Bonearzt
Most people REALLY screw up shanks by using the tapered tool alone by ramming it into the end!!!

The Instrument Innovations set is WONDERFUL!!! The Böhm set is good too but EXPENSIVE and you'll get reamed on shipping!!

Re: Mouthpiece shank straightener

Posted: Thu Feb 11, 2021 11:00 am
by Crazy4Tbone86
I concur with some of the previous entries on this thread. Truing a mouthpiece shank involves a tool for the inside AND the outside. I have seen many mouthpieces that were perfectly round on the inside at the bottom of the shank. Yet, the outside was lopsided and it did not fit properly in the receiver. Also, as previously mentioned, many people who only use a truing tool on the inside end up with over-flaring it at the end of the shank. This too, results in a mouthpiece that does not fit properly in the receiver.

I bought the complete Instrument Innovations kit a few years back and have used it hundreds of times on all of the different mouthpieces from cornet to tuba. It is a fantastic tool. I also have several tapered rods for the inside of the shanks. The one-size-fits-all for brass mouthpieces does not exist. For example: a tapered rod that works well on the inside of a Bach bass trombone shank will not fit properly in a Schilke bass trombone shank and vice versa. Having a variety of tools for the different designs of mouthpieces is important.

Re: Mouthpiece shank straightener

Posted: Thu Feb 11, 2021 11:22 am
by MrHCinDE
I have to add something to my original positive feedback. The Böhm kit (trombone/baritone size) worked great on my small shank mouthpiece, seems to fit a euro shank also pretty well but the collar part for correction of over-expansion doesn‘t really fit a large shank.

I may end up ordering a large shank collar from Instrument Innovations as well!

Re: Mouthpiece shank straightener

Posted: Thu Feb 11, 2021 7:00 pm
by Bonearzt
Crazy4Tbone86 wrote: Thu Feb 11, 2021 11:00 am I concur with some of the previous entries on this thread. Truing a mouthpiece shank involves a tool for the inside AND the outside. I have seen many mouthpieces that were perfectly round on the inside at the bottom of the shank. Yet, the outside was lopsided and it did not fit properly in the receiver. Also, as previously mentioned, many people who only use a truing tool on the inside end up with over-flaring it at the end of the shank. This too, results in a mouthpiece that does not fit properly in the receiver.
I bought the complete Instrument Innovations kit a few years back and have used it hundreds of times on all of the different mouthpieces from cornet to tuba. It is a fantastic tool. I also have several tapered rods for the inside of the shanks. The one-size-fits-all for brass mouthpieces does not exist. For example: a tapered rod that works well on the inside of a Bach bass trombone shank will not fit properly in a Schilke bass trombone shank and vice versa. Having a variety of tools for the different designs of mouthpieces is important.
I turned down the small end of the tapered mandrel to a short cone that seems to work better overall as it only works the very end of the shank where the majority of the damage occurs.
There are several brands that even that doesn't fit, Schilke and Yamaha come to mind and actually some Bach, and for those I use a pair of needle-nose pliers to round out the end.

Re: Mouthpiece shank straightener

Posted: Thu Feb 11, 2021 7:56 pm
by Crazy4Tbone86
I have made a couple of different mouthpiece shank mandrels. However, the majority of mine are from a set of tapered mandrels that I bought at an old hardware store (Sprecher's) in Ephrata, PA in the 1990s. It was one of those old fashioned hardware stores that had everything. I think the store closed down in the early 2000s.

The mandrel set was a "one in a million" find. There are about 9 or 10 mandrels in the set and they are all different widths and tapers......all appropriate for some type of mouthpiece. I really have no idea what the original intent for these mandrels was. The glorious thing about it was that the mandrels were in a clearance bin and I think I got the entire set for under $10!

Re: Mouthpiece shank straightener

Posted: Thu Feb 11, 2021 8:02 pm
by Crazy4Tbone86
I like Eric's idea of trimming those mass-produced mouthpiece truing tools down to a shorter cone. I have a few of them and find that they don't fit many mouthpieces. Trimming them down might make them much more useful. Thanks Eric!