Cutting down a tenor to make an alto

[Hobart]

Okay, so I noticed on my eBay searching for more equipment that I don't need that there are an awful lot of student trombones that won't get used, from 14H's to Bundy's to King 606's.

I know that it is common practice to make a "hackbut" by buying one of these and cutting the bell back to sackbut size, but would it be a bad idea to try to cut the slide and the bell section down to raise the pitch from Bb to Eb? I know it would require a bunch of measuring and precision to get the length right, but a $60 Roth with a somewhat good slide might make a better alto than what I can get from Amazon.
Am I insane, or would it be worth trying?

[BGuttman]

If you are looking to build your skills as a repairman it's an interesting project.

If you are looking to save money, just pay the $200 or so for one of the two Jin Bao stencil altos in the Classifieds. And if you are expecting to pay somebody else to do this job that goes double.

[harrisonreed]

If you want an alto trombone that plays well, you should buy an alto trombone that plays well. That doesn't include $60 tenors or $200 altos. "Plays well for $200" means it doesn't play well.

[elmsandr]

More practically, you have to chop out a LOT of length to get to Eb. Need to go from ~110" in Bb to ~84" in Eb.

I have done this, just for amusement, but it is really hard to do without custom tapers and curves and maintaining a 7 position slide.

Not for nothing, but I *think* that some Conn Altos share the flare tooling with the 2H size tenor. But the bends are unique, IIRC.

Cheers,
Andy

[chromebone]

Larry Minick basically made his altos by cutting down Conn Directors and then put his own bell on them.

The biggest obstacle to doing it yourself would be the bell, there’s no way to maintain a proper taper cutting a tenor bell stem to the size required for an alto.

[brtnats]

Not for nothing, but I *think* that some Conn Altos share the flare tooling with the 2H size tenor. But the bends are unique, IIRC.

Cheers,
Andy

Andy,

I think you’re right. One look at the current Conn altos will tell you their profile has a lot more in common with a 72H bass than an 88H tenor. The bell profile looks like it was copied from a very small tenor tenor mandrel.

[elmsandr]

Just gonna drop this right here...

DSC00916.jpg

[Crazy4Tbone86]

That is very interesting about the similar bell templates for Conn altos and Conn basses. The photo does have a bit of an optical illusion thing going on though.....why does that orange tag look so enormous?

I have created a couple of very successful alto trombones from cut-down tenor bells. I have made hundreds of mistakes along the way. Cutting a tenor down to an alto is not a project for the faint, so here is my advice.....

1. You need to start with a tenor bell that has a very small bell stem. No matter how small the tenor bell stem, you will still need to draw it down and reshape it. I think these bells are great candidates, Conn 2H, Olds Ambassadors, old Thibouville-Lamy and similar older French-style bells.

2. Be ready to reduce the bell stem. It's a tedious process....draw it in, blend with the lower stem using a wooden hammer and roller tools, anneal and repeat the process several times. It's just like the directions on a shampoo bottle...."lather, rinse, repeat..."

3. Keep everything small! If you start with a King 3B tuning slide crook, it will play even better if you reduce it to a King 2B tuning slide. If you make the gooseneck section smaller, it will tend to play better. The smaller the bore sizes in the gooseneck and tuning slide section, the crisper and more in-tune the alto will play.

4. High B-flat (first ledger line above staff in alto clef) is the "make it or break it" note on a home-made alto. If the conversion is not quite right the high B-flat will be under pitch. If your tapers are REALLY off, the high B-flat could easily be as much as 50 cents flat, relative to the rest of the horn. If you can get the high B-flat in tune, your "tenor bell cut down to an alto bell" project is usually a success.

5. Just because an alto slide is shorter than a tenor slide, it doesn't mean that it will be easier to align. For some reason, some of the most challenging slide alignments I have faced have been on alto trombones. I don't know what it is about those short slides, but they can be stubborn little stinkers. If you make your own slide, take your time and make sure that everything is absolutely straight and aligned. Otherwise, you will probably be rebuilding it very soon.

[stewbones43]

I have made a couple of Frankenbone altos from tenors when I was researching the feasibility of an alto pitched in D and there are other problems to face as well as those mentioned above.
Firstly, the hand slide needs to be shortened and you can't just saw off a bit from the bottom of the inner slides. That way you will finish up with no stockings and a leaky slide!! You need to remove the lead pipe, then unsolder both inners from the cork barrels without taking the hand grip/cork barrels section to pieces! Slide the inners up through the cork barrels, remove the excess lengths of inner slides and resolder and then replace the leadpipe (or make it removable!)
Shortening the outer slide is simply a case of removing the bottom bow, sawing off the required length of outer slide and then replacing the bottom bow. Hopefully you won't have to do too much tweaking of the inner and outer slide legs to get the alignment right but it will probably take more than a couple of hours and result in a very full swear box.

As has been stated above, the mating up of assorted bits of bell section, tuning slide legs and goosenecks, can be a problem. For my first attempt I chose an old fashioned British (or French) peashooter bell flare (6 or 6.5in diameter bell and slide bore of around 0.460-0.470in). It worked but the tone was rather brighter than I wanted.
My second attempt worked by removing the tuning slide from the bell section so allowing for more tube length to accommodate the bell section tapers. The tuning was done by making a tuning shank similar to those used on Flugel Horns and Piccolo Trumpets and Soprano Cornets. The tuning shank also incorporated the leadpipe.
The end products, while looking very home-made, worked very well until I was able to fund a Conn 36H for which I built a set of ladder slides so that it can be played in the original Eb/Bb or in D/A which is my preferred tuning.
Good luck with it and report back.

Cheers and stay safe

Stewbones43

[chromebone]

I thought it would be interesting to see how Larry Minick did it. These are pictures of a Conn Director next to my Minick Alto

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[chromebone]

All of the parts are a cut down Director except for the bell flare, leadpipe and his signature cross braces.. The bell is a one piece Beryllium and the leadpipe is his own creation. although it's made up of Conn parts, it plays nothing like a Conn. It's closer to a Bach 39: a clear and compact alto sound but with a bit more heft than a 39. The intonation in each position is good, but the positions line up relative to the bell differently than a tenor or a 36H, so that takes some getting used to.

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[brassmedic]

Just gonna drop this right here...

DSC00916.jpg

I wonder why they needed templates of the bell contour. You'd think the mandrel that they spin it on would determine that.

[Doug Elliott]

I've seen those before. I think they're profiles of the outside of the flare.

[LeTromboniste]

Just gonna drop this right here...

DSC00916.jpg

I wonder why they needed templates of the bell contour. You'd think the mandrel that they spin it on would determine that.

I had the same thought.

Maybe for reference when turning new mandrels?

[brassmedic]

I've seen those before. I think they're profiles of the outside of the flare.

Yeah, that occurred to me right after I posted, so I edited the post.

[brassmedic]

I wonder why they needed templates of the bell contour. You'd think the mandrel that they spin it on would determine that.

I had the same thought.

Maybe for reference when turning new mandrels?

Oh yeah, that makes sense. I suppose pre-CNC they would have had to cut a rough profile of the curve and fine tune it by checking it against the template. Funny thing is, that's exactly what I did when I made my sackbut mandrels, so I don't know why I didn't make that connection.

[brassmedic]

By the way, back on topic, the Czech stencil trombones like Sears Silvertone, etc. have a very narrow bell throat, much like old French trombones, and can be had very cheap. They're good candidates for cut down alto bells.

[Tatertotplaystrombone]

I hate to revive a discussion this old but I happened to have similar questions. I've been trying to acquire new skill and this cutting down a horn to make an alto sound to good.
Has anyone since done this sort of work beside Minick? At the moment I really just need a guide, mostly about how long to make everything to make thing proportional.

Any help would be greatly appreciated.

[brassmedic]

viewtopic.php?p=65701

The 2nd post in this thread has the formula for determining the correct length of tubing. You can figure out the proportion of slide vs. bell length by measuring an existing trombone.

[Tatertotplaystrombone]

Thanks, this should be a good place to start.

[Matt K]

Jeff at Long Island brass did such concessions for awhile