OK, so here's the situation: We make this weird instrument (see www.hurdygurdy.com). It has a rosined wheel, turned by hand
by the player. For about a year we've been making the wheel from a linen-filled phenolic, which is wonderful - no moisture
sensitivity, much less machining time. The only downside is how long it takes to scrape the wheel so it has no runout.

So at breakfast my wife asks me why the wheel always needs to be scraped, i.e. why doesn't it come from the lathe with no
runout - and I have to say I don't really know. I then postulate that it's because the wheel and shaft inevitably exhibit
some chatter when turned on the lathe. and I wonder what I can do about it.

The shaft is about 7" long, and the wheel is 7" diameter x 3/4" thick phenolic. The shaft diameter is 5/16", O-1 drill rod,
held between a 5/16" A3 collet and a live center. The wheel is about 5" from the wide end (in the collet) mounted on a
threaded region, supported by a collar. I'm using a South Bend 9".

Any suggestions for how I might turn this material with less chatter? For example, what side rake and back rake angles are
best for phenolic resin? A slow speed seems to help, but doesn't eliminate the problem. The shaft would still be relatively
"floppy". I could turn the wheel on a thicker, heavier shaft, but then it wouldn't be being turned on the actual shaft that
will be used.


Your help appreciated, as always,

Alden


--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."

If the standard sized bore is 5/16" why not make a mandral from a
heavier piece of round stock, say 3/4". Make a section that is turned
to just under 5/16" Make two larger flanges to support the wheel your
turning that will it on this section in addition to the thickness of
the disk itself, and then thread the remaining portion so a nut or
threaded flange or collar can be snugged up to the disk. Pl;ace the
reduced sectin of the round stock in a collet, and use a live center
to support the opposite end. Aftere completion of machining the disk
round, use a ream to enlarge the hole to 5/16". I would imagine you
could make the intitial hole 5/16" to start with as well.

Becarefull of that phenolic your using as its known to be a
carcinogenic material the dust / smell is highly irritable to nasal
cavities and lungs. It was so much of a hassle to just even drill the
stuff where I used to work with having to have special ventilaors etc
that we soon just stopped doing anything with it in house. I like
working with it myself.



On 5 Aug 2003 22:32:51 GMT, (Alden Hackmann)
wrote:

x-OK, so here's the situation: We make this weird instrument (see www.hurdygurdy.com). It has a rosined wheel, turned by hand
x-by the player. For about a year we've been making the wheel from a linen-filled phenolic, which is wonderful - no moisture
x-sensitivity, much less machining time. The only downside is how long it takes to scrape the wheel so it has no runout.
x-
x-So at breakfast my wife asks me why the wheel always needs to be scraped, i.e. why doesn't it come from the lathe with no
x-runout - and I have to say I don't really know. I then postulate that it's because the wheel and shaft inevitably exhibit
x-some chatter when turned on the lathe. and I wonder what I can do about it.
x-
x-The shaft is about 7" long, and the wheel is 7" diameter x 3/4" thick phenolic. The shaft diameter is 5/16", O-1 drill rod,
x-held between a 5/16" A3 collet and a live center. The wheel is about 5" from the wide end (in the collet) mounted on a
x-threaded region, supported by a collar. I'm using a South Bend 9".
x-
x-Any suggestions for how I might turn this material with less chatter? For example, what side rake and back rake angles are
x-best for phenolic resin? A slow speed seems to help, but doesn't eliminate the problem. The shaft would still be relatively
x-"floppy". I could turn the wheel on a thicker, heavier shaft, but then it wouldn't be being turned on the actual shaft that
x-will be used.
x-
x-
x-Your help appreciated, as always,
x-
x-Alden

--
Visit my website:
http://www.frugalmachinist.com
Contents: foundry and general metal working and lots of related projects.
Regards
Roy aka Chipmaker // Foxeye
Opinions are strictly those of my wife....I have had no input whatsoever.
Remove capital A from chipmAkr for correct email address

In article , Alden Hackmann says...

So at breakfast my wife asks me why the wheel always needs to be scraped, i.e.
why doesn't it come from the lathe with no
runout - and I have to say I don't really know. I then postulate that it's
because the wheel and shaft inevitably exhibit
some chatter when turned on the lathe. and I wonder what I can do about it.

First off, what surface(s) are you hand-scraping, and to what
are they fitted?

I would suggest that you consider simply mounting the phenolic
blanks in OD jaws and and profile both sides, then mount on your
shaft or mandrel and take a skim cut across the OD to clean it
up.

The shaft you are using is pretty thin and flexible, that may
be where some of your chatter is coming from.

LE phenolic can be somewhat abrasive so if you are using HSS
tooling it will get beaten up pretty fast. Carbide if used
instead should be *un*coated as the coatings require a honed
edge and the phenolic really wants a sharp tool and fairly
large postive rake. My personal favorite for this is polycrystaline
diamond inserts from Valenite. I run the tpg221 sized ones
for composites and they last forever and give real sharp
edge.

You will also find that much of the aroma from turning phenolic
goes away when cutting with a very very sharp tool. I think
most of it has to do with burning at the cutting edge.

A beefier mandrel as suggested would be a good way to go.
This is how we used to make sheaves, three operations - profile
first side, profile second side, and mount on mandrel and
turn OD.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

In article ,
jim rozen wrote:
In article , Alden Hackmann says...

So at breakfast my wife asks me why the wheel always needs to be scraped, i.e.
why doesn't it come from the lathe with no
runout - and I have to say I don't really know. I then postulate that it's
because the wheel and shaft inevitably exhibit
some chatter when turned on the lathe. and I wonder what I can do about it.

First off, what surface(s) are you hand-scraping, and to what
are they fitted?

That would be the OD. I know this instrument. For my sins, I
was talked into producing a wheel for it from materials found by the
builder. The rim of the wheel is coated with rosin, and bows the
strings as the crank is turned by hand.

The wood he selected was not seasoned at all, and expanded and
contracted significantly with humidity changes -- along the grain
length. This resulted in the volume produced raising and falling with
the rotation of the wheel.

Another problem was the variation of the finish possible on the
end grain vs the side grain, resulting in an unpleasant rasping sound
beyond that introduced by the "trumpet" -- a vibrating bridge designed
to sound raspy. :-)

I suggested that he get some wood which was a slice out of the
center of the tree (starting with a naturally rather round piece, so the
expansion would be equal. He never did find something which was
reasonable, so I turned him one out of Plexiglas. That was perfect from
my point of view (and that of all others who knew him), as the polished
edge of the Plexiglas would not hold the rosin, and thus produced a very
quiet instrument. (He was never able to play it well, you see. :-) I'm
sure that you are making them for people who *can* play them, and I have
since heard some, and been amazed. My friend was not a good poster-boy
for the instrument.

Unfortunately, he fixed that by gluing some wood veneer around
the rim, with a diagonal joint where it closed, which worked
surprisingly well.

I would suggest that you consider simply mounting the phenolic
blanks in OD jaws and and profile both sides, then mount on your
shaft or mandrel and take a skim cut across the OD to clean it
up.

The shaft you are using is pretty thin and flexible, that may
be where some of your chatter is coming from.

I would consider a custom point for the live center with a
socket to hold the shaft and let the center get close to the wheel to
give it better support. (Or set up a steady rest close to the wheel to
control the vibration.)

I gather that the shaft can't be swallowed deeper into the
collet.

LE phenolic can be somewhat abrasive so if you are using HSS
tooling it will get beaten up pretty fast. Carbide if used
instead should be *un*coated as the coatings require a honed
edge and the phenolic really wants a sharp tool and fairly
large postive rake. My personal favorite for this is polycrystaline
diamond inserts from Valenite. I run the tpg221 sized ones
for composites and they last forever and give real sharp
edge.

That sounds like an excellent suggestion. And I'll bet that it
gets rid of some of the end-grain fuzz which you can get from turning
phenolic.

You will also find that much of the aroma from turning phenolic
goes away when cutting with a very very sharp tool. I think
most of it has to do with burning at the cutting edge.

A beefier mandrel as suggested would be a good way to go.

Or support closer to the wheel.

This is how we used to make sheaves, three operations - profile
first side, profile second side, and mount on mandrel and
turn OD.

I think that the sides are not really critical, assuming that
the hole is square to the surface. (Though it would probably look nicer
if they were faced, too.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
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--- Black Holes are where God is dividing by zero ---

Alden Hackmann wrote (clip) Any suggestions for how I might turn this
material with less chatter.(clip)
^^^^^^^^^^^
I suggest you support the wheel on a round steel jig, with three pins on it,
say 3/4" diameter, at 120 degrees around the center. Three holes in your
phenolic blank will hold it with no chatter and very little runout. If you
think the holes look bad, decorate them so they fit with the ornamentation
on the hurdy-gurdy (viol?)

BTW, I love that kind of music.

I really don't know. It sort of resembles it in smell though. The
linen or canvas lamiunated stuff is supposedly made with formaldehyde.
Thats whats supposed to be so bad for you. I have some nice piece of
this stuff, from 1/16" thick to 3" thick, and everything in between,
some in 36 x 36 inch sheets, and some sheets a lot larger. It used to
be a mainstay in aircraft, but its nbot quite a popular as it used to
be. No matter what, I still like working and using this stuff.

On Wed, 06 Aug 2003 04:23:40 -0500, Richard J Kinch
wrote:

x-Roy Hauer writes:
x-
x- Becarefull of that phenolic your using as its known to be a
x- carcinogenic material the dust / smell is highly irritable to nasal
x- cavities and lungs. It was so much of a hassle to just even drill the
x- stuff where I used to work with having to have special ventilaors etc
x- that we soon just stopped doing anything with it in house.
x-
x-Isn't Formica made from phenolic? You sure get a lot of it airborne when
x-trimming countertops.

--
Visit my website:
http://www.frugalmachinist.com
Contents: foundry and general metal working and lots of related projects.
Regards
Roy aka Chipmaker // Foxeye
Opinions are strictly those of my wife....I have had no input whatsoever.
Remove capital A from chipmAkr for correct email address

jim rozen writes:

First off, what surface(s) are you hand-scraping, and to what
are they fitted?

The outer rim is what gets scraped, not in the usual machine-tool scraping manner (I think, not ever having done that) but
with a heavy wood plane blade or a cabinet scraper. The reason it gets scraped is to smooth it for the contact with the
strings. The strings rest on the wheel, which is rosined and acts like a bow. To keep the tone even, the wheel must have
very little runout: if there's variation in the diameter, the string pressure on the wheel varies, and the sound changes.
Instead of getting a nice smooth "ummmmmmmmmmmmmmmmmmmmmmmmmmmmm", it sounds like "MMMMMM-mmmmmm-MMMMMMM-mmmmmm".

I would suggest that you consider simply mounting the phenolic
blanks in OD jaws and and profile both sides, then mount on your
shaft or mandrel and take a skim cut across the OD to clean it
up.

The shaft you are using is pretty thin and flexible, that may
be where some of your chatter is coming from.

Initially when making the wheel I put the sawn blank on a faceplate to turn it down to the basic diameter, and to drill and
tap it (5/16"-18). There is less chatter in this situation, but of course the shafts have a little runout, and the tapped
hole is never exactly perfectly square to the blank - so between these two, there's always some runout in the wheel when it's
on the shaft. Consequently I make up matched sets of wheels and shafts: once a set has been assigned to an instrument, it's
not interchangeable with another set.

LE phenolic can be somewhat abrasive so if you are using HSS
tooling it will get beaten up pretty fast. Carbide if used
instead should be *un*coated as the coatings require a honed
edge and the phenolic really wants a sharp tool and fairly
large postive rake. My personal favorite for this is polycrystaline
diamond inserts from Valenite. I run the tpg221 sized ones
for composites and they last forever and give real sharp
edge.

My past experience with carbide, at least with metal, is that the poor old 9" SB lathe wasn't rigid enough for it.
Suggestions (besides a bigger lathe)? I'm using an Aloris QC toolpost.

You will also find that much of the aroma from turning phenolic
goes away when cutting with a very very sharp tool. I think
most of it has to do with burning at the cutting edge.

That would be nice. ;-)

A beefier mandrel as suggested would be a good way to go.
This is how we used to make sheaves, three operations - profile
first side, profile second side, and mount on mandrel and
turn OD.

The sides are less important - just the OD (which is not square, but is cut at several degrees angle.)

Thank you,

Alden
--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."

In article , Alden Hackmann says...

Initially when making the wheel I put the sawn blank on a faceplate to turn it
down to the basic diameter, and to drill and
tap it (5/16"-18). There is less chatter in this situation, but of course the
shafts have a little runout, and the tapped
hole is never exactly perfectly square to the blank - so between these two,
there's always some runout in the wheel when it's
on the shaft. Consequently I make up matched sets of wheels and shafts: once a
set has been assigned to an instrument, it's
not interchangeable with another set.

Hmmm. I would stay away from a tapped hole to mount it to the
shaft, for the reason you say, this does not provide good
locational accuracy for the finished assembly. A better
design would be a straight bore in the phenolic, and a
round section on the shaft. The shaft could have a shoulder
at one side and threads on the other, a nut could compress
the phenolic up against the shoulder.

Tapped holes do *not* work well if you are trying to minimize
radial runout. Just taking the part off the shaft, and putting
it back on, will give you a few thousanths of error right there.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

jim rozen writes:

Hmmm. I would stay away from a tapped hole to mount it to the
shaft, for the reason you say, this does not provide good
locational accuracy for the finished assembly. A better
design would be a straight bore in the phenolic, and a
round section on the shaft. The shaft could have a shoulder
at one side and threads on the other, a nut could compress
the phenolic up against the shoulder.

This doesn't work with the system we're using, for esthetic reasons. ;-( However...

Tapped holes do *not* work well if you are trying to minimize
radial runout. Just taking the part off the shaft, and putting
it back on, will give you a few thousanths of error right there.

How about a wheel that is tapped (half) and reamed (half)? Would the phenolic threads hold up? I would think so. Would the
half that's bored straight be enough to stabilize it? That's the way we used to do it, with a nylon insert in a wood wheel,
until we had several incidents of the nylon threads being stripped.

Alden
--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."

In article , Alden Hackmann says...

How about a wheel that is tapped (half) and reamed (half)? Would the phenolic
threads hold up? I would think so. Would the
half that's bored straight be enough to stabilize it?

I would say that if the phenolic is about an inch thick now,
one half inch of threads would probably do fine. A half inch
of straight shaft would certainly center it up properly.

I would suggest putting the blank in a chuck, and profiling one
face, and then drilling and tapping the entire thickness. Then
go in with a boring bar and bore out to the shaft diameter.

The final step would be holding in a mandrel, *centered* on
the finished bore, with a center hub as I previously described,
and turn the OD. Then the OD will be exactly concentric
with the bore.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

The shaft diameter is 5/16", O-1 drill rod,
held between a 5/16" A3 collet and a live center. The wheel is about 5" from
the wide end (in the collet) mounted on a
threaded region, supported by a collar.

The drive rod is winding up.

Bore a 5/16 hole in a faceplate, and GLUE the disk to some blocks to make it
parallel to the faceplate. Put the blocks out near the edge to be machined. It
won't chatter that way because it's coupled to the large mass of the faceplate.



Yours,

Doug Goncz, Replikon Research, Seven Corners, VA
Unequal distribution of apoptotic factors regulates
embryonic neuronal stem cell proliferation

In article ,
Alden Hackmann wrote:
jim rozen writes:

First off, what surface(s) are you hand-scraping, and to what
are they fitted?

The outer rim is what gets scraped, not in the usual machine-tool scraping manner (I think, not ever having done that) but
with a heavy wood plane blade or a cabinet scraper. The reason it gets scraped is to smooth it for the contact with the
strings. The strings rest on the wheel, which is rosined and acts like a bow. To keep the tone even, the wheel must have
very little runout: if there's variation in the diameter, the string pressure on the wheel varies, and the sound changes.
Instead of getting a nice smooth "ummmmmmmmmmmmmmmmmmmmmmmmmmmmm", it sounds like "MMMMMM-mmmmmm-MMMMMMM-mmmmmm".

I've heard that -- with a buzz added from wood end-grain
extending with humidity. :-)

[ ... ]

The shaft you are using is pretty thin and flexible, that may
be where some of your chatter is coming from.

Initially when making the wheel I put the sawn blank on a faceplate to
turn it down to the basic diameter, and to drill and tap it (5/16"-18).
There is less chatter in this situation, but of course the shafts have a
little runout, and the tapped hole is never exactly perfectly square to
the blank - so between these two, there's always some runout in the
wheel when it's on the shaft.

*Tapped* hole? You mean that the wheel threads onto the shaft?
How do you tap it? In the lathe, just after drilling, while still on
the faceplate? If you go to a drill press, you're introducing an
additional place where error can come in.

I would instead of tapping it, drill it slightly undersized, and
ream to size in the lathe (or bore before reaming, to make sure that
things are on-center), and make that size a light press fit on the
shaft. Then I would use a tiny end mill, or a reciprocating saw, to
make a short radial slot from the center hole, and drill the shaft for a
pin which would be pressed in and prevent the wheel from ever rotating on
the shaft. I would have a thread on the shaft just *after* the wheel,
and a screw-on nut (perhaps with pin spanner holes) to secure the wheel
to the shaft. The shaft *should* have a shoulder to assure that the
wheel is square to the shaft, and to resist the thrust of the nut.

Consequently I make up matched sets of
wheels and shafts: once a set has been assigned to an instrument, it's
not interchangeable with another set.

Is the wheel permanently mounted to the shaft from the time it
is machined to final installation? If it comes off for intermediate
operations, and there is no pin or other feature to assure alignment
between the shaft and the wheel, each removal and replacement can
introduce more error producing runout.

LE phenolic can be somewhat abrasive so if you are using HSS
tooling it will get beaten up pretty fast. Carbide if used
instead should be *un*coated as the coatings require a honed
edge and the phenolic really wants a sharp tool and fairly
large postive rake. My personal favorite for this is polycrystaline
diamond inserts from Valenite. I run the tpg221 sized ones
for composites and they last forever and give real sharp
edge.

My past experience with carbide, at least with metal, is that the poor
old 9" SB lathe wasn't rigid enough for it. Suggestions (besides a
bigger lathe)? I'm using an Aloris QC toolpost.

1) Tighten the gibs on the compound and the cross-slide to minimize
the give there.

2) Use the largest tool shank you can for the size of toolpost
and holders. With a 9" SB, you must be using an AXA Aloris, so
the maximum shank is probably 1/2". (BXA lets you use 5/8",
buying more rigidity, but I think that is too big for a 9" SB.

3) Minimize the extension of the tool from the holder. (There is
a fancy Aloris tool holder which offers support to allow you to
clear a live center while turning. The top view is somewhat
like this:

+------+
| \
| O \
| \
| O |
| |
| O |\|
| |
| O ( 0 )
| |
| O |/|
| |
| |
+----------+

This gives you a bit more rigidity if you can't crank the
toolpost any closer to the workpiece. I use one of these when
threading using carbide insert tools, and may get another
someday.

There is also a tool holder which has clamps for insert tooling
directly on the holder -- no extra shanks to deal with. More
rigid, but it limits your choice of inserts to whatever is
supported by that holder. There are two variants, one with
positive rake, and one with negative. I have the negative rake
one since it works with the inserts which I use elsewhere. (With
chipbreaker grooves which turn it into an actual positive rake,
but you get thick tool inserts with no undercut for relief, as
that is provided by the negative rake.) Unfortunately, these
are the triangular inserts, and I don't know whether the
suggested PCD (PolyCrystaline Diamond) inserts are available in
that format. They would be a good choice, in any case. These
holders are double-ended, offering one insert for turning, and
one for facing in the same tool, only requiring transferring to
the other dovetail on the toolpost.

4) Minimize overhang in the compound. Ideally, the toolpost should
be centered over the pivot/mount of the compound to the
cross-slide.

5) Don't use the inexpensive sets of five insert holders (parallel
left, angled left, neutral, angled right and parallel right), as
they tend to be rather wimpy, and to use thinner inserts,
without a proper Carbide anvil supporting them, so they break
much more easily, and otherwise lead to chatter.

You will also find that much of the aroma from turning phenolic
goes away when cutting with a very very sharp tool. I think
most of it has to do with burning at the cutting edge.

That would be nice. ;-)

A beefier mandrel as suggested would be a good way to go.
This is how we used to make sheaves, three operations - profile
first side, profile second side, and mount on mandrel and
turn OD.

The sides are less important - just the OD (which is not square, but is
cut at several degrees angle.)

Isn't it crowned? That was how the ones which I made were
produced. (Back before I had such nice tooling and machines to work
with. :-)

Best of luck,
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 ---

In article ,
Alden Hackmann wrote:
jim rozen writes:

Hmmm. I would stay away from a tapped hole to mount it to the
shaft, for the reason you say, this does not provide good
locational accuracy for the finished assembly. A better
design would be a straight bore in the phenolic, and a
round section on the shaft. The shaft could have a shoulder
at one side and threads on the other, a nut could compress
the phenolic up against the shoulder.

This doesn't work with the system we're using, for esthetic reasons.
;-( However...

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.

Add that to an anti-rotation pin (as I just suggested in another
branch of this thread), and you assure that it goes back in the same
position.

Tapped holes do *not* work well if you are trying to minimize
radial runout. Just taking the part off the shaft, and putting
it back on, will give you a few thousanths of error right there.

How about a wheel that is tapped (half) and reamed (half)? Would the
phenolic threads hold up?

How thick is the wheel at the hub? What pitch are the 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.

Otherwise, this is similar to how a lathe's spindle centers its
chuck, with a register shoulder and threads for the force.

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?

I would think so. Would the half that's
bored straight be enough to stabilize it? That's the way we used to do
it, with a nylon insert in a wood wheel, until we had several incidents
of the nylon threads being stripped.

I think that this answers your question. :-) It just isn't long
enough to devote half of the thickness to threads and half to a reamed
hole for centering.

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.

BTW Have you looked into using Delrin (acetal) for your wheel? It
is available in both Balck and natural (a sort of light cream
colored white. and is a lot more durable than nylon.

Good luck,
DoN.


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
before they start to get folded. I've been having to re-format
your lines so the whole of the text is visible in my editor,
instead of part of it hiding beyond the right margin. Since
some are worse than others, I suspect that you are using a
proportional pitch font for posting (which means that ASCII
graphics will appear distorted -- including my earlier attempt
to show the shape of the special Aloris tool holder which would
be more rigid than what you are using. If it was
unintelligible, go back to look at it with a fixed pitch font
selected, such as Courier (always a safe choice. :-)
--
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--- Black Holes are where God is dividing by zero ---

In article , DoN. Nichols says...

How thick is the wheel at the hub? What pitch are the 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.

I would think that from an engineering perspective, even a
half inch thick wheel could be mounted on a small shaft this
way, with a threaded shaft with a 'register diameter' on it,
the same way that a lathe chuck fits on a threaded spindle.

I would propose a design with 0.200 of very snug register
diameter, and 0.3 inch of threads, proabably about 20 threads
per inch or so, maybe 24. LE phenolic is actually really
really strong and threads up nicely. Key to this design
is cutting the threads in the blank fairly loose, so that
the register diameter does the work of centering the shaft.

Another approach would be to eliminate the threads altogether.
I would suggest performing linear knurling (not cross hatched)
on the shaft in the central region where the wheel fits, and
then boring the hub to be a very tight press-up on the knurled
section. It sounds to me like the driving torque is pretty
modest and I could imagine that a properly done press-up
onto knurling like that could have the .313 shaft twist
up before the joint slips.

Otherwise, this is similar to how a lathe's spindle centers its
chuck, with a register shoulder and threads for the force.

Oh. Great minds think alike! :^)

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?

The knurled, pressed-up joint would solve that issue nicely....

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

(DoN. Nichols) writes:

*Tapped* hole? You mean that the wheel threads onto the shaft?
How do you tap it? In the lathe, just after drilling, while still on
the faceplate? If you go to a drill press, you're introducing an
additional place where error can come in.

The wheel is drilled and tapped on the lathe.

I would instead of tapping it, drill it slightly undersized, and
ream to size in the lathe (or bore before reaming, to make sure that
things are on-center), and make that size a light press fit on the
shaft. Then I would use a tiny end mill, or a reciprocating saw, to
make a short radial slot from the center hole, and drill the shaft for a
pin which would be pressed in and prevent the wheel from ever rotating on
the shaft. I would have a thread on the shaft just *after* the wheel,
and a screw-on nut (perhaps with pin spanner holes) to secure the wheel
to the shaft. The shaft *should* have a shoulder to assure that the
wheel is square to the shaft, and to resist the thrust of the nut.

There is a shoulder, 1/2" diameter.

The press fit/pin/nut are a cool idea, but the wheel needs to fit through a hole that has minimal clearance (1/32" - 1/16")
around the wheel. I don't think the body would stand up well to the shaft being pressed in.

Consequently I make up matched sets of
wheels and shafts: once a set has been assigned to an instrument, it's
not interchangeable with another set.

Is the wheel permanently mounted to the shaft from the time it
is machined to final installation? If it comes off for intermediate
operations, and there is no pin or other feature to assure alignment
between the shaft and the wheel, each removal and replacement can
introduce more error producing runout.

The shoulder does this, I assume. The wheel is removed from the shaft after machining.

[much useful advice deleted]

4) Minimize overhang in the compound. Ideally, the toolpost should
be centered over the pivot/mount of the compound to the
cross-slide.

Ah, there's the rub - as it is, I've had to slide the toolpost back so ~1/2" is hanging out. I probably need to make the cool
flat cross-slide from Metal Lathe Accessories.

5) Don't use the inexpensive sets of five insert holders (parallel
left, angled left, neutral, angled right and parallel right), as
they tend to be rather wimpy, and to use thinner inserts,
without a proper Carbide anvil supporting them, so they break
much more easily, and otherwise lead to chatter.

Um - a little lost here. Could you point me to some MSC Big Book pages showing the wimpy stuff and some showing the good
stuff? I'm afraid that I wouldn't know a good insert holder if it fell on me... but in any case, I guess I know which inserts
I'm looking for, so I can let that choice help me to find good holders.

Isn't it crowned? That was how the ones which I made were
produced. (Back before I had such nice tooling and machines to work
with. :-)

The surface is flat, with a small radius at the edge to keep the string from being cut by a sharp edge. I've tried
instruments with crowned wheels - not a good sound. The surface is much better flat, like the hairs of a bow.

Thank you for your comments,

Alden
--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."

(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.

How thick is the wheel at the hub? What pitch are the threads?

3/4" thick wheel, 5/16-18 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.

Otherwise, this is similar to how a lathe's spindle centers its
chuck, with a register shoulder and threads for the force.

Cool - got it.

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. 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!)

I would think so. Would the half that's
bored straight be enough to stabilize it? That's the way we used to do
it, with a nylon insert in a wood wheel, until we had several incidents
of the nylon threads being stripped.

I think that this answers your question. :-) It just isn't long
enough to devote half of the thickness to threads and half to a reamed
hole for centering.

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.

BTW Have you looked into using Delrin (acetal) for your wheel? It
is available in both Balck 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.

Good luck,
DoN.


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.

Alden
--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."

jim rozen writes:


Respectfully disagree. The material you have chosen
(LE phenolic) is quite tough and would take a press
up of substantial proportions without failing.
Simply putting linear knurling on teh steel shaft
will make it drive quite well.

Sorry - I should have specified the body of the instrument, not the wheel.
I'm sure the wheel and shaft would do fine with this. The situation is
that we need to be able to install the shaft and wheel in the instrument
and remove it again fairly easily.

To give you a better idea of the instrument, here's one of our progress
pages: http://www.hurdygurdy.com/progress/021216.htm. A few photos down,
VG37 is being drilled and tapped for the bearings and shaft, and in the
next photo, VG37 is sitting with the wheel installed. Once the soundboard
is positioned, we'll take it out again, and glue on the soundboard. We'll
put it in again to position the bridge and the keybox, and we'll take it
out for finishing, and put it in again to string it up.

Thanks for your ideas,

Alden
--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."

SNIP

BTW Have you looked into using Delrin (acetal) for your wheel? It
is available in both Balck 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.

Greetings Alden,
I don't know about the rosin sticking, but acetal resin absorbs almost
no water. It is vey stable with changing humidity. In fact, I make
scuba parts out of it and the lack of water absorption was one of the
main reasons for choosing this material. It is a good engineering
plastic and can be used for bearings, knobs, etc.. Soon, I will be
sending out to several people small pieces of this plastic that are
just scrap to me. If you want some let me know. All you pay is the
postage marked on the box. About 4 dollars.
Cheers,
Eric

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 ---

In article ,
Alden Hackmann wrote:
(DoN. Nichols) writes:

*Tapped* hole? You mean that the wheel threads onto the shaft?
How do you tap it? In the lathe, just after drilling, while still on
the faceplate? If you go to a drill press, you're introducing an
additional place where error can come in.

The wheel is drilled and tapped on the lathe.

O.K. So it should be on-axis, then.

I would instead of tapping it, drill it slightly undersized, and
ream to size in the lathe (or bore before reaming, to make sure that

[ ... ]

to the shaft. The shaft *should* have a shoulder to assure that the
wheel is square to the shaft, and to resist the thrust of the nut.

There is a shoulder, 1/2" diameter.

The press fit/pin/nut are a cool idea, but the wheel needs to fit
through a hole that has minimal clearance (1/32" - 1/16") around the
wheel. I don't think the body would stand up well to the shaft being
pressed in.

O.K. I can see that. But a gentle press fit, not a firm one
might be do-able, with the pin dropped into a hole through about 2/3 of
the shaft's diameter at the last moment before entering the wheel. (I
presume that it would otherwise have problems feeding through the
bearing at the crank end.

Consequently I make up matched sets of
wheels and shafts: once a set has been assigned to an instrument, it's
not interchangeable with another set.

Is the wheel permanently mounted to the shaft from the time it
is machined to final installation? If it comes off for intermediate
operations, and there is no pin or other feature to assure alignment
between the shaft and the wheel, each removal and replacement can
introduce more error producing runout.

The shoulder does this, I assume. The wheel is removed from the shaft
after machining.

Thus a need to be able to assure the orientation of the wheel
relative to the shaft on re-assembly in the instrument.

[much useful advice deleted]

4) Minimize overhang in the compound. Ideally, the toolpost should
be centered over the pivot/mount of the compound to the
cross-slide.

Ah, there's the rub - as it is, I've had to slide the toolpost back so
~1/2" is hanging out. I probably need to make the cool flat cross-slide
from Metal Lathe Accessories.

That would probably make it a lot better for your purposes.

5) Don't use the inexpensive sets of five insert holders (parallel
left, angled left, neutral, angled right and parallel right), as
they tend to be rather wimpy, and to use thinner inserts,
without a proper Carbide anvil supporting them, so they break
much more easily, and otherwise lead to chatter.

Um - a little lost here. Could you point me to some MSC Big Book pages
showing the wimpy stuff and some showing the good stuff? I'm afraid
that I wouldn't know a good insert holder if it fell on me... but in any
case, I guess I know which inserts I'm looking for, so I can let that
choice help me to find good holders.

O.K. Let's see what I can find (but the first clue is that the
wimpy ones come in sets of five, sometimes boxed, sometimes in a wooden
stand with holes for the five cutters, two spare screws for attaching
the inserts, and one or two hex keys (Allen wrenches) for the screws.

Names like Valenite and Carbaloy are found on the good ones,
plus some from Israel (Iscar). Let's start on page 617, upper left-hand
corner, for the PCD tipped inserts. (These would last a lot longer and
do a cleaner cut on your composite wheels. (From those, you can select
holders to fit the inserts available. (*Don't* use these on iron or
steel, however, it will convert the diamond to extra carbon in the steel
alloy, which doesn't help you at all.

If you use carbide, don't use the TiN coated ones (or the other
coatings), as it results in a slight rounding (dulling) of the edge.
Good in working steel, but bad for composites.

You'll have to stick to 1/2" square shanks, thanks to your
toolholder. Look for ones with carbide anvils as separate replaceable
items. it gives better support to the inserts. Valenite holders start
on page 622. Some styles are not available in the 1/2" size, which is
another thing to control your choices. (Find a combination of inserts
and holders which will work with your lathe and your materials.

Valenite is only one good brand, and happens to be first in the
catalog. (Reverse alphabetical order by any chance?)

Page 633 includes a diagram of how at least one style of good
holder goes together.

The cheap sets are shown on page 553, and I've found them to be
inadequate even for a 5" Emco-Maier Compact-5/CNC. Once I found a good
supply of the diamond inserts which fit the tools which came with it, I
was quite happy, and have totally retired the cheap sets.

I hope this helps. I'm putting the catalog back on the shelf
while I've still got some circulation to my legs. :-)

Isn't it crowned? That was how the ones which I made were
produced. (Back before I had such nice tooling and machines to work
with. :-)

The surface is flat, with a small radius at the edge to keep the string
from being cut by a sharp edge. I've tried instruments with crowned
wheels - not a good sound. The surface is much better flat, like the
hairs of a bow.

O.K. But angled to match the angle of the strings?

Thank you for your comments,

You're welcome. I hope that they help.

Good Luck,
DoN.

P.S. My wife recognizes your name from some of her newsgroups (and/or
mailing lists).
--
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 ---

In article , DoN. Nichols says...

If you use carbide, don't use the TiN coated ones (or the other
coatings), as it results in a slight rounding (dulling) of the edge.
Good in working steel, but bad for composites.

He should purchase *one* tpg221 polycystaline diamond insert
from valenite. Unless he dings it accidentally, it will last
him literally forever turning phenolic.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

(DoN. Nichols) writes:

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.)

The trompette only sounds when (a) the wheel is being turned forward and
(b) the wheel is being turned faster. The player can silence the buzzing
of the trompette simply by turning the wheel more slowly.

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.

This isn't a connection I'm familiar with - can you describe it to me?

Thanks,

Alden

--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."

(DoN. Nichols) writes:

O.K. I can see that. But a gentle press fit, not a firm one
might be do-able, with the pin dropped into a hole through about 2/3 of
the shaft's diameter at the last moment before entering the wheel. (I
presume that it would otherwise have problems feeding through the
bearing at the crank end.

[more useful advice deleted]

I hope this helps. I'm putting the catalog back on the shelf
while I've still got some circulation to my legs. :-)

Yeah, I keep mine on the floor under the electronics bench, so that I can
put it DOWN after use. ;-)

O.K. But angled to match the angle of the strings?

Correct.

DoN.

P.S. My wife recognizes your name from some of her newsgroups (and/or
mailing lists).

Ah - either famous or infamous...

A
--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."

In article ,
Ned Simmons wrote:
In article ,
says...
(DoN. Nichols) writes:

*Tapped* hole? You mean that the wheel threads onto the shaft?
How do you tap it? In the lathe, just after drilling, while still on
the faceplate? If you go to a drill press, you're introducing an
additional place where error can come in.

The wheel is drilled and tapped on the lathe.

[ ... ]

I haven't read this whole thread, so may have missed some
important bit, but if I were doing this, I'd think about
making a shaft something like this:

http://www.suscom-maine.net/~nsimmons/HurdyShaft.jpg

*Nice* rendering!

The wheel would have a tapered socket (possibly in a piece
of steel or brass epoxied into the center of the disc) to
match that on the shaft. A nut on the thread would pull the
disc onto the taper. If the angle on the taper is steep
enough (depends on the coeff of friction between shaft and
socket), it will be self releasing or require only a light
tap to release.

That sounds good to me. If fitted to something like that, it
should be very repeatable on any refitting. Of course, the making of
the shafts in reasonable quantities (e.g. onesey-twosey per setup) would
be a bit of a pain -- especially on a small machine. A bit of a runout
gap between the threads and the taper would be a bit easier to handle on
a non-CNC machine, and getting the taper just right might also be a
pain. (It looks short enough to do on the compound, so if you did a
wheel and a shaft with the same compound setup, that should work --
until the next batch which might be different if the compound setting
were to be changed for other work. (E,g, for cutting the thread. :-)

You could have both the taper and thread in the socket,
eliminating the need for the nut, and also supplying the
means to push off the taper, but then it seems the thread
may be more likely to influence the runout.

It also might be hard to start to unscrew, since you've got the
taper fighting you.

Might be worth
a try.

Surface grinder wheels are often mounted on arbors similar
to this.

Is that why you had the neatly rendered shaft image handy, or
did you do this just for the reply?

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
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--- Black Holes are where God is dividing by zero ---

In article ,
Ned Simmons wrote:
In article , dnichols@d-
and-d.com says...
In article ,
Ned Simmons wrote:

[ ... ]

The wheel would have a tapered socket (possibly in a piece
of steel or brass epoxied into the center of the disc) to
match that on the shaft. A nut on the thread would pull the
disc onto the taper. If the angle on the taper is steep
enough (depends on the coeff of friction between shaft and
socket), it will be self releasing or require only a light
tap to release.

That sounds good to me. If fitted to something like that, it
should be very repeatable on any refitting. Of course, the making of
the shafts in reasonable quantities (e.g. onesey-twosey per setup) would
be a bit of a pain -- especially on a small machine. A bit of a runout
gap between the threads and the taper would be a bit easier to handle on
a non-CNC machine, and getting the taper just right might also be a
pain. (It looks short enough to do on the compound, so if you did a
wheel and a shaft with the same compound setup, that should work --
until the next batch which might be different if the compound setting
were to be changed for other work.

Very true, but with a bit of care, the parts should be
interchangeable within a run.

What would be nice would be a reamer to produce the precise
taper in the wheel, so all you would need would be to set the compound
to match each time. Or, with a more gentle taper, you could leave it
set up on a taper attachment. I would suggest using a Morse taper as
the standard, so you could use relatively inexpensive reamers. Probably
a MT-1 (big end) or MT-2 (small end). Any larger would be too big, I
think.

You could have both the taper and thread in the socket,
eliminating the need for the nut, and also supplying the
means to push off the taper, but then it seems the thread
may be more likely to influence the runout.

It also might be hard to start to unscrew, since you've got the
taper fighting you.

Yes, you'd want to be careful about socking it down too
tight.

Bear in mind that the rim of the wheel is bowing strings, which
are vibrating tangent to the rim of the wheel, and the friction is
tailored with a coating of rosin (same as for a fiddle bow), so this is
acting a bit like a tiny impact wrench -- lots of repeated pressure
spikes which would probably tighten the wheel up during playing, and
thus make things difficult to start free afterwards. I would personally
feel happier with a nut -- but one whose gripping surfaces could be
disguised as a decorative feature. For example, start with a cylinder,
and drill eight or twelve holes parallel to the axis around the cylinder
from one end (not going all the way through). Then turn it to about a
20-30 degree taper, until you come out below the holes at the small end.
Then a matching female cone, with two or three inserted pins of drill
rod would give a nice grip on the cone, and it would all *look* like
decoration. The female cone could perhaps be an incomplete circle, like
a 'C', so it could be slipped on over the extension of the shaft to the
final bearing)

Of course, I am not the original poster, I just got mixed up in
this because I've helped build these things in the past (not nearly so
nice as his, though.)

[ ... ]

Surface grinder wheels are often mounted on arbors similar
to this.

Is that why you had the neatly rendered shaft image handy, or
did you do this just for the reply?

No, I did it to save time and avoid ambiguity in my
description. Slow typist, middling to fast CAD modeler
here. It probably took less than 5 minutes to model the
part, paste the screen capture into an image editor, crop
it, and upload it.

O.K. What software are you using? (I'll bet that it is one of
the Windows-based ones, so I can't run it. :-) And how long did it take
you to get that fast?

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 ---

In article , dnichols@d-
and-d.com says...
In article ,
Ned Simmons wrote:
In article , dnichols@d-
and-d.com says...
In article ,
Ned Simmons wrote:


What would be nice would be a reamer to produce the precise
taper in the wheel, so all you would need would be to set the compound
to match each time. Or, with a more gentle taper, you could leave it
set up on a taper attachment. I would suggest using a Morse taper as
the standard, so you could use relatively inexpensive reamers. Probably
a MT-1 (big end) or MT-2 (small end). Any larger would be too big, I
think.

I'd be concerned that a Morse taper would be too difficult
to release without anything to work against. I think you'd
want the taper to be just barely self locking.


You could have both the taper and thread in the socket,
eliminating the need for the nut, and also supplying the
means to push off the taper, but then it seems the thread
may be more likely to influence the runout.

It also might be hard to start to unscrew, since you've got the
taper fighting you.

Yes, you'd want to be careful about socking it down too
tight.

Bear in mind that the rim of the wheel is bowing strings, which
are vibrating tangent to the rim of the wheel, and the friction is
tailored with a coating of rosin (same as for a fiddle bow), so this is
acting a bit like a tiny impact wrench -- lots of repeated pressure
spikes which would probably tighten the wheel up during playing, and
thus make things difficult to start free afterwards.

Yeah, I was wondering about that when I replied before, but
have a hard time imagining it would get awfully tight, but
then my experience with hurdy-gurdys is limited to watching
"Captains Courageous". g


No, I did it to save time and avoid ambiguity in my
description. Slow typist, middling to fast CAD modeler
here. It probably took less than 5 minutes to model the
part, paste the screen capture into an image editor, crop
it, and upload it.

O.K. What software are you using? (I'll bet that it is one of
the Windows-based ones, so I can't run it. :-) And how long did it take
you to get that fast?


You'd win that bet, it's Autodesk Inventor, and Autodesk is
pretty much in bed with Microsoft. There were a lot of
unhappy folks when they dropped support for Apple several
years ago, and despite a lot of pressure to port to Linux,
I don't see it happening any time soon.

Someone here was trying out Alibre and seemed to be happy
with it. IIRC it was around $500 vs. around $4000 for
Inventor, Solidworks, Solid Edge, and the like.

Ned Simmons

In article ,
Ned Simmons wrote:
In article , dnichols@d-
and-d.com says...

[ ... ]

The alternative is to leave a shoulder so you can use a Jacobs
chuck fork on it,

You could put two thru holes in the face of the nut, 180
degrees apart, and two mating tapped holes in the disc hub.
Unscrew the nut a bit til the holes line up, insert a
couple machine screws, and pull the hub off the taper. In
that case, the MT might be practical.

That sounds good -- but you would need to be able to disguise
the holes as decoration (and I had a branch of the thread (or was it an
e-mail branch?) in which I had a circle of holes in the nut parallel to
the axis, and then the nut is turned to a cone, leaving the holes as
decorative ribbing -- but something which could be gripped by a special
design wrench. Perhaps *all* of those holes could go all the way
through, reducing the amount you need to rotate the nut before you line
up. But you would need a piece to fit on the cone and provide a square
surface for the screw head to operate against.

Or -- there could be a shoulder *behind* the wheel (which is
where we were before we got to the taper idea) against which the tips of
the screws could bear for extraction.

[ ... ]

Manuel(Spencer Tracy), the Portugese sailor who befriends
Mickey Rooney plays one, the kind we're talking about here,
a couple times in the movie. It's a good movie, though I'm
not sure how Manuel was able to keep that hurdy-gurdy in
good tune on a Gloucester fishing schooner out on the Grand
Banks.g

Kind of like the sailors keeping a concertina in good condition
at sea. :-) The expensive English system concertinas were really out of
the reach of the sailors price-wise anyway. And what was far more
likely to be used at see were cheap (e.g. $1.00-$3.00, depending on the
period) one-row button accordions. Dead simple to play -- at least to
sort of accompany your singing when relaxing off-duty. Cheap enough to
replace after every voyage. (There were also cheap German-made
concertinas, which might have been within reach, but like the
accordions, they would die by the end of the voyage -- probably even
when given extraordinary care.)

Note that there are at least two things which go by that name,
both crank-operated. The earlier is the instrument which we are

[ ... ]

The older style (which has a French name which I would misspell
if I tried to type it) takes more skill, and I have heard the difference
between a skilled player and an unskilled one, and it is amazing.

Sort of like the bagpipes, eh?

Similar sound, except that the bagpipes (at least the Scottish
warpipes) are *loud*, while this is a more polite indoor instrument.
There are "polite" bagpipes in several cultures.

[ ... ]

fine tuning of a scale. Sometimes, there are two rows of the keys, with
longer flags sticking up between the other keys, so you can have a row
of "white notes" and one of "black notes".

I've only seen one in person once. Someone had several in
progress and a finished hurdy-gurdy at a folk craft show
here in Maine a few years ago. I found them fascinating.

They are -- and I've examined an antique one once, part of the
display collection in a rather good music store in Washington D.C.

[ ... ]

I could probably use VNC to get some of that with a Windows box
displayed on a unix box, but it is slow. I do use that for running the

[ ... ]

I wouldn't even want to attempt it. The 3d parametric
modelers are much more graphics and compute intensive than
typical wireframe CAD or 3d CAD. Every time I need to put
together a new box I thank the gamers for making the
required hardware affordable.

:-)

My Sun Ultra-2 has a Creator-3D card in it, which should be
quite nice, if I can get the programs to use it. It is things like this
that make me use the Sun as the keyboard/display and leave the program
(which was written for Intel-based linux) on a linux box across the net.
It might be worthwhile boosting that link to 100BaseT instead of
10BaseT.

It's ironic that so little is available for linux/unix
since the predecessors(ProE, for example) of the current
batch of mid-range modelers were all unix programs.

They want to *sell* them, and linux users are a notoriously
poor market. :-)

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 ---

Take a look at CadKey ...

I am about 1/4 down the page taking out a "printed" stereolithograpy part
that I designed in CadKey.

http://www.cadkey.com/resources/educorner/page1.asp

http://www.cadkey.com

and
their educational distributor
http://www.tecedu.com

If you are a student or staff/teacher, k - college, you can get the latest
version for very little. It is a very good program for about $190. This is
the full program. The only restriction is that you do not use it for
commercial projects.

It does 3D, Parametric, Skinning, and much more. It will import: IGES, DFX,
DWG, IGES (one pass), STEP, ACIS SAT, Parasolid, and STL files.
It will export: all of the above plus GIF, WMF, Uniplot, VRML (Picture it),
and SLA (Picture it).

I teach at a middle school and am piloting a class in CAD at the middle
school (7th and 8th grade) level this year. I used it last year as part of a
6th grade class.

I went to the TecEdu "summer camp" and got the latest program for going to
the class. Next year I intend to take the classes offered in SurfCam and
Chief Architect.


"DoN. Nichols" wrote in message
...
In article ,
Ned Simmons wrote:
In article , dnichols@d-
and-d.com says...

[ ... ]

The alternative is to leave a shoulder so you can use a Jacobs
chuck fork on it,

You could put two thru holes in the face of the nut, 180
degrees apart, and two mating tapped holes in the disc hub.
Unscrew the nut a bit til the holes line up, insert a
couple machine screws, and pull the hub off the taper. In
that case, the MT might be practical.

That sounds good -- but you would need to be able to disguise
the holes as decoration (and I had a branch of the thread (or was it an
e-mail branch?) in which I had a circle of holes in the nut parallel to
the axis, and then the nut is turned to a cone, leaving the holes as
decorative ribbing -- but something which could be gripped by a special
design wrench. Perhaps *all* of those holes could go all the way
through, reducing the amount you need to rotate the nut before you line
up. But you would need a piece to fit on the cone and provide a square
surface for the screw head to operate against.

Or -- there could be a shoulder *behind* the wheel (which is
where we were before we got to the taper idea) against which the tips of
the screws could bear for extraction.

[ ... ]

Manuel(Spencer Tracy), the Portugese sailor who befriends
Mickey Rooney plays one, the kind we're talking about here,
a couple times in the movie. It's a good movie, though I'm
not sure how Manuel was able to keep that hurdy-gurdy in
good tune on a Gloucester fishing schooner out on the Grand
Banks.g

Kind of like the sailors keeping a concertina in good condition
at sea. :-) The expensive English system concertinas were really out of
the reach of the sailors price-wise anyway. And what was far more
likely to be used at see were cheap (e.g. $1.00-$3.00, depending on the
period) one-row button accordions. Dead simple to play -- at least to
sort of accompany your singing when relaxing off-duty. Cheap enough to
replace after every voyage. (There were also cheap German-made
concertinas, which might have been within reach, but like the
accordions, they would die by the end of the voyage -- probably even
when given extraordinary care.)

Note that there are at least two things which go by that name,
both crank-operated. The earlier is the instrument which we are

[ ... ]

The older style (which has a French name which I would misspell
if I tried to type it) takes more skill, and I have heard the
difference
between a skilled player and an unskilled one, and it is amazing.

Sort of like the bagpipes, eh?

Similar sound, except that the bagpipes (at least the Scottish
warpipes) are *loud*, while this is a more polite indoor instrument.
There are "polite" bagpipes in several cultures.

[ ... ]

fine tuning of a scale. Sometimes, there are two rows of the keys,
with
longer flags sticking up between the other keys, so you can have a row
of "white notes" and one of "black notes".

I've only seen one in person once. Someone had several in
progress and a finished hurdy-gurdy at a folk craft show
here in Maine a few years ago. I found them fascinating.

They are -- and I've examined an antique one once, part of the
display collection in a rather good music store in Washington D.C.

[ ... ]

I could probably use VNC to get some of that with a Windows box
displayed on a unix box, but it is slow. I do use that for running the

[ ... ]

I wouldn't even want to attempt it. The 3d parametric
modelers are much more graphics and compute intensive than
typical wireframe CAD or 3d CAD. Every time I need to put
together a new box I thank the gamers for making the
required hardware affordable.

:-)

My Sun Ultra-2 has a Creator-3D card in it, which should be
quite nice, if I can get the programs to use it. It is things like this
that make me use the Sun as the keyboard/display and leave the program
(which was written for Intel-based linux) on a linux box across the net.
It might be worthwhile boosting that link to 100BaseT instead of
10BaseT.

It's ironic that so little is available for linux/unix
since the predecessors(ProE, for example) of the current
batch of mid-range modelers were all unix programs.

They want to *sell* them, and linux users are a notoriously
poor market. :-)

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 ---

Ned Simmons writes:


Manuel(Spencer Tracy), the Portugese sailor who befriends
Mickey Rooney plays one, the kind we're talking about here,
a couple times in the movie. It's a good movie, though I'm
not sure how Manuel was able to keep that hurdy-gurdy in
good tune on a Gloucester fishing schooner out on the Grand
Banks.g

Good question, easy answer: you never hear him play it. The sound is
dubbed in, and it's not even a hurdy-gurdy playing, it's an orchestra
sounding not even remotely like a HG. The most you hear from the
instrument itself is a heart-rending "thump" when Manuel puts it down a
bit too hard.

Sort of like the bagpipes, eh?

Almost exactly like bagpipes, but with a rhythmic buzzing.

I've only seen one in person once. Someone had several in
progress and a finished hurdy-gurdy at a folk craft show
here in Maine a few years ago. I found them fascinating.

We probably know the guy: Matt Szostak lives in Camden, and is one of the
few professional HG makers in the US. (The other ones all live in our
house.)

Alden
--
Alden F.M. Hackmann
Web: http://www.hurdygurdy.com/hg/hghome.html
"Beati illi qui in circulum circumeunt, fient enim magnae rotae."