In article ,
Alden Hackmann wrote:
(DoN. Nichols) writes:
The nut doesn't have to *look* like a nut. It can be a cone,
with pin holes or grooves (which could be disguised as decoration)
allowing a special wrench to tighten it firmly.
Hmm - I'd need to think about that.
I can think of several ways to disguies it as decoration.
How thick is the wheel at the hub? What pitch are the threads?
3/4" thick wheel, 5/16-18 threads
Better than I thought. With half of that as register cylinder,
that leaves 3/8" length, which is over six threads.
I think that you are using a wheel of about 1/2" thickness, which is not
really enough if half of its length is taken up by threads. And the
rather coarse threads which would seem to make sense in phenolic would
result in not enough of them to really trust.
Then 3/4" should be fine.
I think so.
[ ... ]
Do you ever encounter a player who likes to turn the wheel
backwards most of the time? Do you have problems with it coming off
under those circumstances?
It's quite an unnatural motion. A very few players use a quick
back-and-forth motion sometimes for a special effect.
Isn't the action of the "trumpet" (vibrating bridge) sensitive
to the direction of the wheel? Could a player opt to silence it by
turning backwards for a while? (Yes -- there are other ways to silence
it, but they require taking a hand from the crank, or the keys for a
little while.)
We have
occasionally had difficulties with the wheel coming undone when the crank
is removed, as players often do when storing the instrument. To this end,
we have been milling a small pair of flats on the exposed end of the shaft
for a 1/4" box wrench. (The old method was a pair of Vise-Grips(TM) -
yuck!)
You could also use a hole through the diameter and a pin-wrench
to hold it from turning.
I could also see a bayonet style connection between the crank
and the shaft, so you have to press the crank towards the body to
disengage the fittings.
[ ... ]
Does the shaft stick out much beyond the hole? If not, a
cone-shaped nut could look rather nice, and be a lot stronger than the
phenolic, let alone than the nylon.
The shaft extends about 1.4", into the head bearing.
O.K. So you've got bearings on either side of the wheel,
instead of two bearings mounted to a cylinder between the wheel and the
crank.
BTW Have you looked into using Delrin (acetal) for your wheel? It
is available in both Black and natural (a sort of light cream
colored white. and is a lot more durable than nylon.
We need the rosin to stick, and for the material to be completely stable
regardless of the humidity.
You've just gotten an excellent offer on some samples in a
second followup to this. Get some, and try the rosin to see whether it
sticks. Your stability with humidity question has already been answered.
Perhaps you have been thinking of Teflon, which is a sure
guarantee that the rosin won't stick.
But it might help to sandblast the rim after turning it with
Delrin (acetal). I've never actually tried to get it to hold onto
rosin.
[ ... ]
P.S. Can you trim your line length a bit? Standard length should
be no longer than 72 characters, to allow some levels of quoting
Sorry - I'm using ASCII, but the screen was really big. Hopefully my
resizing to 80 columns has solved this.
That has made things a *lot* nicer. I'm using an editor which
is trained to cut the lines at 72 no matter how wide the screen is, so I
don't have to worry about that (except to turn that option *off* if
I need really wide lines. :-)
Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. |
http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---