A couple folks asked me to update my progress on this topic. I was
looking for octagonal aluminum stock to make tension adjusting knobs for
carbon fiber bows for stringed instruments. Main reason for octagonal
stock is that, apparently, the knobs have always been octagonal.

Well, we abandoned the idea of octagonal stock, instead I designed a
finned knob. Finning was the easiest way to reduce weight, and it lends
a high tech look to a high tech bow. The bow can be seen at:
http://www.keithmcmillen.com/kbow/
the picture at the bottom of the page shows it best, this is a violin bow.

I'm making the finned knobs in 4 sizes, and the black block (called a
frog adapter, seen between the bow and the circuit board) in 3 sizes.
This has been one of the neatest projects I've been involved with in a
long time. Outside of the functional requirements, weight reduction was
primary, with asthetics being important too. The final designs are based
upon Keith's initial drawings, but was given carte blanch to reduce
weight anywhere I thought we could get away with it. Weight is such an
issue in the violin bows that the tension screws are titanium, which
combined with the finned knob, saved about 1.5 grams. Last round of
weight reduction on the violin adapter netted a .8 gram reduction, which
was significant as a percentage of the overall weight.

The first pilot run is out for anodize and should be back Wednesday.
I'll take some detailed pics of the frog adapters and knobs and post
them to my website, with a link here to follow up.

Just thought a few folks might enjoy seeing what I was up to....


Jon

On Dec 1, 9:31*pm, Jon Anderson wrote:
A couple folks asked me to update my progress on this topic. I was
looking for octagonal aluminum stock to make tension adjusting knobs for
carbon fiber bows for stringed instruments. Main reason for octagonal
stock is that, apparently, the knobs have always been octagonal.

Well, we abandoned the idea of octagonal stock, instead I designed a
finned knob. Finning was the easiest way to reduce weight, and it lends
a high tech look to a high tech bow. The bow can be seen at:http://www.keithmcmillen.com/kbow/
the picture at the bottom of the page shows it best, this is a violin bow..

I'm making the finned knobs in 4 sizes, and the black block (called a
frog adapter, seen between the bow and the circuit board) in 3 sizes.
This has been one of the neatest projects I've been involved with in a
long time. Outside of the functional requirements, weight reduction was
primary, with asthetics being important too. The final designs are based
upon Keith's initial drawings, but was given carte blanch to reduce
weight anywhere I thought we could get away with it. Weight is such an
issue in the violin bows that the tension screws are titanium, which
combined with the finned knob, saved about 1.5 grams. Last round of
weight reduction on the violin adapter netted a .8 gram reduction, which
was significant as a percentage of the overall weight.

The first pilot run is out for anodize and should be back Wednesday.
I'll take some detailed pics of the frog adapters and knobs and post
them to my website, with a link here to follow up.

Just thought a few folks might enjoy seeing what I was up to....

Jon

Jon

Sounds like an interesting project. I played the cello through high
school an occasionally since, the enlarged frog seems cumbersome.
What have you done to miniaturize the electronics?

CarlBoyd

Carl wrote:

Sounds like an interesting project. I played the cello through high
school an occasionally since, the enlarged frog seems cumbersome.
What have you done to miniaturize the electronics?

I don't play so can't comment. But users seem to be more than willing to
deal with the larger frog in exchange for what the electronics offer. If
you back up to the main page, there's three YouTube videos embedded that
show some of what it will do.

The sum of my involvement is the tension knobs and frog adapters. Given
what all it will do, I think there's already been a lot of
miniaturization! I do have a prototype circuit board, and it is jam
packed with really small surface mount components. Don't think it's
going to get much smaller.

Of course, all this stuff weighs something, which is why the jihad to
reduce weight. I'm not sure where the production models are ending up,
but the violin bows are most weight sensitive and are very close to a
'standard' bow.


Jon

"Jon Anderson" wrote in message
...
Carl wrote:

Sounds like an interesting project. I played the cello through high
school an occasionally since, the enlarged frog seems cumbersome.
What have you done to miniaturize the electronics?

I don't play so can't comment. But users seem to be more than willing to
deal with the larger frog in exchange for what the electronics offer. If
you back up to the main page, there's three YouTube videos embedded that
show some of what it will do.

The sum of my involvement is the tension knobs and frog adapters. Given
what all it will do, I think there's already been a lot of
miniaturization! I do have a prototype circuit board, and it is jam
packed with really small surface mount components. Don't think it's
going to get much smaller.

Of course, all this stuff weighs something, which is why the jihad to
reduce weight. I'm not sure where the production models are ending up,
but the violin bows are most weight sensitive and are very close to a
'standard' bow.

Nice knob handle.
But if weight is such a factor, why not eliminate most of the OD altogether,
and provide turning torque like a wingnut, with two ears at the end?
Less elegant, f'sure, but also much lighter. And not as easy to make.

How much of the $3995 is for your knob?

--
PV'd




Jon

Proctologically Violated©® wrote:

Nice knob handle.
But if weight is such a factor, why not eliminate most of the OD altogether,
and provide turning torque like a wingnut, with two ears at the end?
Less elegant, f'sure, but also much lighter. And not as easy to make.

Looks are an issue. My customer says his bow maker pronounced the finned
knob the biggest advance in asthetics in 200 years. I found that very
hard to believe myself though he assures me that in instruments, change
comes slowly. But I did something right, there's people wanting to buy
just the knob/screw for their existing bows, they might well end up
being a separate product in and of themselves.

How much of the $3995 is for your knob?

Not much, but enough... G My Omni-turn really whips those things right
out. Takes longer to modify the screws. What I wish I had right now is a
Fanuc Robodrill or similar for the frog adapters. I could really go to
town on those things with a 10k spindle....


Jon

"Jon Anderson" wrote in message
...
Proctologically Violated©® wrote:

Nice knob handle.
But if weight is such a factor, why not eliminate most of the OD
altogether, and provide turning torque like a wingnut, with two ears at
the end?
Less elegant, f'sure, but also much lighter. And not as easy to make.

Looks are an issue. My customer says his bow maker pronounced the finned
knob the biggest advance in asthetics in 200 years. I found that very hard
to believe myself though he assures me that in instruments, change comes
slowly. But I did something right, there's people wanting to buy just the
knob/screw for their existing bows, they might well end up being a
separate product in and of themselves.

That's always a good idea.



How much of the $3995 is for your knob?

Not much, but enough... G My Omni-turn really whips those things right
out. Takes longer to modify the screws. What I wish I had right now is a
Fanuc Robodrill or similar for the frog adapters. I could really go to
town on those things with a 10k spindle....

I noticed the bow hairs are attached directly to the board. DAT seems like
a mechanically dicey proposition unto itself. Not as much tension as on the
violin strings themselves, but must be some.

The musical equivalent of a heart-rate monitor, eh?

--
PV'd




Jon

Proctologically Violated©® wrote:

I noticed the bow hairs are attached directly to the board. DAT seems like
a mechanically dicey proposition unto itself. Not as much tension as on the
violin strings themselves, but must be some.

There's some tension all right. We've taken steps to insure the bond
between the board and the frog adapter is a permanent one. At the board
end, the strings are attached to a piezo electric sensor. This is what
feeds back how hard the bow is being pressed against the instrument's
strings.

BTW, didn't you post to a.m.c. a little while back asking what else you
could do with your machining center besides machining? If that was you,
ping me off list, got a link for ya. Tried to email, but got a bounce.

Jon

"Jon Anderson" wrote in message
...
Proctologically Violated©® wrote:

I noticed the bow hairs are attached directly to the board. DAT seems
like a mechanically dicey proposition unto itself. Not as much tension
as on the violin strings themselves, but must be some.

There's some tension all right. We've taken steps to insure the bond
between the board and the frog adapter is a permanent one. At the board
end, the strings are attached to a piezo electric sensor. This is what
feeds back how hard the bow is being pressed against the instrument's
strings.

BTW, didn't you post to a.m.c. a little while back asking what else you
could do with your machining center besides machining? If that was you,
ping me off list, got a link for ya. Tried to email, but got a bounce.

I occasionally speculate on alternative uses for a vmc -- I think the last
was as a tubing bender.
I'm currently working on using the vmc as a microwave oven and friction
welder.
I'll drop you a line.

Your violin gizmo is actually very impressive engineering, mechanically and
electronically. Kudos to you/Mcmillen.

I initially thought it was a teaching/training/practice device, but now I
see it is for synthesizing sound -- presumably in conjunction with standard
guitar-like pickups, but maybe in replacement of. Very inneresting. I'm
sure this took some time to develop/perfect.

--
PV'd







Jon

Proctologically Violated©® wrote:
Kudos to you/Mcmillen.
Kudos to Keith and crew, I've played the most minor of parts in the
whole thing.


Jon

On Mon, 01 Dec 2008 18:31:25 -0800, Jon Anderson
wrote:

A couple folks asked me to update my progress on this topic. I was
looking for octagonal aluminum stock to make tension adjusting knobs for
carbon fiber bows for stringed instruments.

Weight is such an
issue in the violin bows that the tension screws are titanium, which
combined with the finned knob, saved about 1.5 grams.

Do they balance feel like a regular bow?

Can a local luthier rehair it or must it be returned to you - not that
I'm in the market, just idle curiosity.

RWL

GeoLane at PTD dot NET wrote:

Do they balance feel like a regular bow?

Can a local luthier rehair it or must it be returned to you - not that
I'm in the market, just idle curiosity.

There is some change in balance, but apparently more than offset by the
new freedom it offers to be creative.
I don't know if a luthier can rehair it or not. I don't manufacture the
whole bow, just two components of it.

Jon