The collar will be threaded though, it will screw onto the horn body and the mouth piece will screw into it.
The candidates for the collar, they are about 2 X 1 1/4" at the smaller end.
Here is one drilled 1/4", mounted on a mandrel and rough turned:
Once roughed out it is mounted in a chuck and drilled for the Tap; Bit is 17/32nds for the 5/8-11 Tap.
I Chuck the Tap up in the tail-stock (Jacobs bit) leave it loose, turn the head-stock by hand and let it pull the Tap in. Maybe 3/4s of a turn at time backing out after each to clear out the chips.
This is it test fitted on the horn.
Here it is rough turned, it is mounted on a bolt that has had the head cut off, you see it has been shorted some. Once the mouth piece is made it will get screwed into the collar and they both will be finished turned at the same time.
Notes:
1. I used Dr. Jackson's Leather Rejuvenator as a lube for all threading work on horns. Why? Cause I've
been using it for years and it works for me.
2. I can't stress enough about going S L O W when threading horn, trust me I have thought I was ok
only to get threads that looked like a Corn cob with the corn gone.
3. The Mandrel is a standard Pen tuning model with a couple Bronze and Wooden bushings add as
needed.
4. One more, when tapping through a piece I start with a tapered tap and finish it off with a bottoming.
Next will be the Mouth piece.
Tim
