TubaForum.net

I am starting to plan a 5th valve addition to my MW20. Realistically... it won't be until late summer or fall so I have time, but I want to get all the parts together.. make any ferrules and the linkages components and braces I need before I start taking things off my tuba.. I have other hobby projects, both instrument and non-instrument, that needs to come first..

The bore is 19.5mm it just slightly smaller than Miraphone 186/188 19.6mm. I am thinking that either a parted out Miraphone rotor assembly or Chinese miraclone parts are going to be my best bet.

For the trumpet and trombone projects in the past.. I've just purchased eBay parts horns on the cheap and scavenged what I needed.. Not so much an option here.

I have a spare Miraphone 186 rotor if you decide to go through with it.

I have two, using one in a project, and can send you what I don't use.

Some people enjoy tinkering and struggling with things and doing things for the first time and saying that they did it themselves.

I'm more interested in having something than making the thing that I eventually have. I will make things if I want them badly enough, and I'll even add a room on to my house mostly myself if I think that hiring other people is not only going to cost 10 times as much but end up being crappy. (I finally realized that I would have to add this room on to my house myself if it was going to get done, otherwise it would have cost six figures and would have been a piece of sh!t, which it is not... EVEN THOUGH I never done an addition on a house before, and certainly not log construction.)



It's a little more challenging to use another maker's parts, because it would be very slightly different and all of your measurements that you would have to offer would need to be pretty precise, but maybe not as difficult as one might expect, because the arm going over to the rotor could be a simple piece of 3mm rod that you would cut to length and thread yourself, which would be the thing that would vary the most out of the entire assembly.

The least troublesome way to accomplish this is to find someone willing to order the parts for you from Miraphone, and assembled absolutely as far as they can be pre-assembled.

Maybe even with the places where the solder joints would be located masked off by them with masking tape and have them go ahead and polish and lacquer everything with their epoxy lacquer.

A little bit of the lacquer would likely get burned in installation, but it's way less trouble than hand polishing all those little nooks and crannies and then putting crappy rattle can on it.

Again, I'm not one of those "life is about the journey" people, at least not when it comes to acquiring equipment. Once I decide that I need or desire the equipment, I just want to have it and would prefer (other than examples offered above) to simply have it so I can use it.

Also, even if you bought parts from Buffet (which is considerably more difficult than buying them from a Miraphone dealer who would cooperate with you), the rotor and tubing aren't going to be the same, because the West German shop where your tuba was built has long been closed, and any sort of similar instruments with the m-w name on them today are made in the (rebuilt from the ground up decades ago) B&S shop in extreme eastern Germany.

19.5mm vs. 19.6mm..??

dp wrote:pfft

I hear ya Joe.. However my brain is in a different place.. All my hobby projects instrument or otherwise are done with the idea of being educational and fun as well as practical. If my goal was really just to have a 5th valve I would just take it to Buckeye Brass and pay Rob to do it. All of my Internet projects have been about identifying one specific skill and using the project as as platform to practice to practice that skill. Designing the 1st valve triggers for my trumpets, trumpet C builds, shortening 1st 3rd valve circuits on my Eb, leadpipe swaps and recruiting gap adjustment.. etc were each about I've been trying to lay out a self paced curriculum on instrument design and modification... This one is a but of a step up in difficulty.. but the targeted skills are figuring out how to design and route a valve circuit, and how to design and install the thumb linkage.

I also want to keep it 100% reversible. Luckily I want to raise the leadpipe up an inch or so anyway and I have a long pull on the main tuning slide too get it down to 440 already.. so if my calculations are right I can add in the extra length without cutting the leadpipe or anywhere else.

Plan is to try to find a used 186/188 BBb 3rd valve circuit or slide.. Building bending rigs is for a future lesson.

Tight 90° bends don't do so well with typical bending methods.

For this reason, manufacturers will bend the tubes the best they can manage to - so where they managed to fit the crudely bent tubes into two piece molds that were built by a milling machine. The halves of the molds are then secured the ends of the tubes to be discarded are compression fit to a hydraulic system, and those bends are then hydraulically blown out to the shapes of the molds. That's not something in which I'm willing to invest, particularly not at my age, and particular since I can either buy or salvage such parts and in various bore sizes.