[soybean]

… to make a neck tenon smaller? There is an alto neck I really want to try on my sax. Unfortunately, it is a little too large. I know that it is easier to make a tenon larger than to compress it. But my friend said there is a machine that can do this job. Does anyone here know about this tool/machine?

 

[Sigmund451]

How large is too large? That makes a big difference.

 

[Gordon (NZ)]

I'd call it a tool rather than a machine.

Here is one http://www.ferreestools.com/Sax_tenon_shrinker.htm
Boehm make one too.

I made collets, and a holding system so I could use them in a vice, such that they were compressed from three locations around the circumference, which I consider to keep the collets more cylindrical during operation, seeing the Ferrees one effectively still has pressure applied mainly across just a diameter.

 

[soybean]

How large is too large? That makes a big difference.

Good Question. I'll measure the neck and interior of my sax and get back to you. The Ferrees website says; "Best results are obtained if you limit shrinking to about .010" per collet".

 

[soybean]

I made collets, and a holding system…

Thanks Gordon. So you made your own tools to do this. Please explain in a little more detail "the Ferrees one effectively still has pressure applied mainly across just a diameter".

 

[Sakshama]

I have that Flute tool that I never used. If you find somebody that can explain it how to do it with this: https://picasaweb.google.com/106825855321850509556/FluteTool
I'm ready to help you.

 

[eugeneherman]

Soybean... What type of neck swap are you attempting?

 

[Gordon (NZ)]

Thanks Gordon. So you made your own tools to do this. Please explain in a little more detail "the Ferrees one effectively still has pressure applied mainly across just a diameter".

A milling or CNC machine's collet chuck operates inside a tapered housing, in such a way that it applies pressure equally right around the collet.

The Ferrees tool is nothing like this. The clamping housing applies pressure on the collet across a diameter of the collet, i.e. in a plane at right angles to the split in the tool, because that is the plane housing the direction of force of the tightening device, i.e. the screw in the housing. Sure, the housing is shaped to fit the collet a bit, and that will stop the collet becoming excessively oval, and ensure that the diametric force described, applies to a slightly greater sector of the collet at each end of the diameter, but the force is still applied across a diameter nevertheless, such that the collet is distorted slightly oval during use. When we are adjusting the minutiae of the shape of a tenon, this cannot be ideal.

A proper collet chuck system would be a lot better, but expensive. My system at least makes some improvement by applying the force around the collet in three areas spaced at 120 degree intervals.

The photo shows my simple tool set up in a vice, but without the sax tenon in place. It was really a prototype, and would be quicker to use if it were made to fit the jaw of the vice, rather than being turned on a lathe, then cut to this shape.

 

[eugeneherman]

Gordon, Very smart and effective looking set up... Great idea!

 

[Graysax]

I actually have a set of 5C Collets for my lathe in the smallest increments.

It's amazing how many times I use my lathe without even powering it on!

I have not found a better system for shrinking tenons. Yes, it was an expensive setup, however, they have many other uses in my shop.

Charlie

 

[Wind_Mill]

I have the Boehm tenon shrinking tool & collet die set. Along with my Votaw Gorilla Expander, they make this job fairly routine and precise. With the Boehm/collet tool, I tighten down very lightly, release pressure, and then turn the tenon about 45 degrees, repeating until I've rotated the neck a full turn.

Usually I have the rest of the horn in possession when I do this (allowing for the final fit with 1000-grit lapping compound), otherwise it's a matter of trusting someone else's digital caliper and skills to use it. Neck receivers can be occasionally out of round and may need that addressed before one gets too excited about achieving a leak-free fit.

Soybean, did you find how much you'd need the tenon shrunk?

 

[simso]

Tools / Collars

 

[eugeneherman]

No problem in your studio simso eh?