TromboneChat

I'm planning to convert my Holton 168 from a closed wrap to an open wrap. The closed wrap has a lot of red rot.

I will also replace the aging Holton rotor (from the 1950's) with a new Rotax rotor. I will retain the short-throw string action of the trigger.

Does anyone have any suggestions on the open wrap design? or anything else for that matter?

How about having the job done by a great tech with experience in these projects?

I've put a lot of work and time into this.

Instead of the open wrap extending out the back and hitting everything behind you, how about up? That way you only have to worry about low ceilings!!

Probably easiest to just get a whole valve section / kit, or so I would think. Your first step should be to find the tech who will be doing the work, and see what their thoughts are.

Also, are you sure that the F-attachment has red rot, or is it just red after losing lacquer and exposure to air?

Jim Becker at Osmun in Acton, MA has done a number of these and has already given me his recommendations on how/what to do. I'm good with his recommendations too.

I'm asking here in the TC to make sure we haven't missed any great ideas.

And yes, according those who know this sort of thing it is definitely red rot.

The "Alessi" style wrap with a distinctive "C" on the return port is probably the most common wrap I see for conversions. You can pick up tubing pretty cheap though from a lot of manufacturers so you might just want to go that route. But as noted by others, going with someone who has done this before would give you a lot of knowledge about who is best to order from (relative availability, price, quality, etc.)

Burgerbob wrote: ↑Thu Jun 16, 2022 12:12 pm I've put a lot of work and time into this.

Instead of the open wrap extending out the back and hitting everything behind you, how about up? That way you only have to worry about low ceilings!!

Interesting idea. I can see just how much time you've already invested. You should work on Photoshopping skills to really sell the idea.

patrickosmith wrote: ↑Thu Jun 16, 2022 4:55 pm
Interesting idea. I can see just how much time you've already invested. You should work on Photoshopping skills to really sell the idea.

And I thought that was my best work...

In any case, Instrument Innovations sells some wrap parts that might be all you need. You'd have to ask your tech, of course.

The valve tubing will be a different size with your new setup- on later Holtons, at least, all valve tubing is .585, basses and tenors. Modern tenors use .562. I'm not sure what your horn is though.

Burgerbob wrote: ↑Thu Jun 16, 2022 5:07 pm [The valve tubing will be a different size with your new setup- on later Holtons, at least, all valve tubing is .585, basses and tenors. Modern tenors use .562. I'm not sure what your horn is though.

Yes, the Holton has .585 tubing in the wrap tubing which will be replaced by .562. The Rotax rotor remains at full open circle whereas the Holton rotor is a more constrained oval shape. The overall result should be a net gain.

patrickosmith wrote: ↑Thu Jun 16, 2022 5:18 pm
Yes, the Holton has .585 tubing in the wrap tubing which will be replaced by .562. The Rotax rotor remains at full open circle whereas the Holton rotor is a more constrained oval shape. The overall result should be a net gain.

Yes, I agree. I have a 258 (probably for sale soon) that I think would come to LIFE with a Rotax or similar conversion.

I'm doing my due diligence in researching designs and parts. I'm surprised no one mentioned a choice between Caidex and Rotax rotary valves. Any thoughts on that?

You might also look at Instrument Innovations (Olsen), a greatly improved rotary valve, along with Olsen’s redesign of the axial flow (Thayer) valve, which he calls an Infinity Valve. https://instrumentinnovations.com/

There is also the Hagmann valve from René Hagmann in Switzerland. http://www.trombone.ch/

Both companies have tubing and brace kits available to easily convert from your existing wrap to something designed with their valves in mind.

patrickosmith wrote: ↑Sat Jun 18, 2022 5:45 am I'm doing my due diligence in researching designs and parts. I'm surprised no one mentioned a choice between Caidex and Rotax rotary valves. Any thoughts on that?

The Caidex is a relatively new design, and I honestly have never seen or heard one in the flesh. A lot of of what I have read is still at the "So how is it actually better than the Rotax?" stage. I don't know if Willson even has it fitted to any of their production trombones.

I do see that Stephens trombones (Steve Shires) is using them, but in general, I don't see many. There is only so much you can improve the wheel I guess.