TromboneChat

A thread about aftermarket pipe for a vintage Conn got me revisit the notion of doing it on my 73H, so I went to a tech to see if he can pull the pipe without damaging it.

Turns out, it didn’t have a leadpipe at all! Instead, its inner tube itself had the taper so that it’d accept normal (presumably Remington shank, but it does accept Morse taper just as stably) mouthpiece.

It is a 1970 N series 73H. Is anyone aware of such a thing?? Apparently Conn did do something like that with decent number of trumpets. Assuming all-stock 73H would have a normal leadpipe (wouldn’t it??), would this be a factory option?? Or, anyone heard of doing this with an aftermarket inner tube??

Find a second opinion...

Quote from: slideorama on Jan 25, 2018, 02:01PMFind a second opinion...

The top tube was removed from the brace, and I was able to see the taper from outside of the tube, so I am fairly convinced—otherwise I would have done so, no question.

Quote from: MaestroHound on Jan 25, 2018, 02:10PMThe top tube was removed from the brace, and I was able to see the taper from outside of the tube, so I am fairly convinced—otherwise I would have done so, no question.

Most inner tubes can be unsoldered and pushed straight up through the cork barrel/receiver assembly.  Is that what he did?

I can't imagine how one would give an inner tube a taper...  I don't get it...

Quote from: greenbean on Jan 25, 2018, 02:33PMMost inner tubes can be unsoldered and pushed straight up through the cork barrel/receiver assembly.  Is that what he did?

I can't imagine how one would give an inner tube a taper...  I don't get it...

Yes, that is how I saw the tube’s outer profile at the receiver end. I don’t get it either but it plays really well.

Standard Bach large-shank mouthpiece dimensions are .496" diameter at the end and .546" at 1" (which is the specified insertion depth). Now, Remington dimensions are different, but not THAT different. You can put a Remington shank into a Bach receiver and vice versa. They wobble a bit, but that's a matter of a few thousandths and a different taper.

So, if the ID of the inner tube is .562" (as it should be for a 73H) that would mean that it have to get smaller, then expand back out to the end - but still smaller than .562". Is that what you're seeing?

Of course, you could do some of that by tinkering with the wall thickness, but I doubt that that's what is going on in this case.

Quote from: JohnL on Jan 25, 2018, 04:13PMSo, if the ID of the inner tube is .562" (as it should be for a 73H) that would mean that it have to get smaller, then expand back out to the end - but still smaller than .562". Is that what you're seeing?

Yes, kind of like a waist line, for the lack of different way to describe it. From the outside, tube was tapered to get smaller for short length at the top (just about a mouthpiece receiver would be) then expanded to .562”.

Quote from: JohnL on Jan 25, 2018, 04:13PMSo, if the ID of the inner tube is .562" (as it should be for a 73H) that would mean that it have to get smaller, then expand back out to the end - but still smaller than .562". Is that what you're seeing?

Yes, kind of like a waist line, for the lack of different way to describe it. From the outside, tube was tapered to get smaller for short length at the top (just about a mouthpiece receiver would be) then expanded to .562”.