I picked up a few brass candle sticks in garage sales. I wanted to use one
for a brass sundial. It has a long stem and a cup for the candle. The stem
is irregular with some patterns on it.

I cut the stem off where I thought it would be just about right length for
the gnomon. I tried to "turn" it in my old drill press. It turned out not so
bad, I put a 10-32 thread on one end and tried to re-profile the rest of
it. It is about 5 cm long so I thought I would use the live center I have
for my sanding drums.
like this one:

http://www.leevalley.com/wood/page.a...02&cat=1,42500

This is where I run into a bit of a problem - drilling the centre hole.

The candlestick was made in India, I am not sure how. Either way not very
well so the whole thing is a bit asymmetrical. I tried to determine the
centre of the end to drill a concentric hole but found it almost impossible.
In the end when hooked up to the live centre (which is loose on the drill
press table) the live centre was running around in a small circle whatever I
did.

Now I understand (I hope!) that on a lathe the live centre on the taistock
is lined up with the centre of the chuck on the head stock and the hole will
be drilled in the centre by default. Not having a lathe the best way I found
to drill centres in a round stock is to make a paper tube around it and use
a tight fitting transfer punch to mark the centre. This works fine if the
stock is cylindrical, not on a candle stick stem which is not.

I found a thread on this group from 2004 which provided several options of
which the only one viable in my situation would have been to use a 3-jaw
chuck to center under the drill press spindle and then substitute the centre
drill. And I am indeed looking for a cheap 3-jaw chuck.

Are there any other suggestions ("Buy a lathe!" does not count)?

The other thing that puzzles me (and please note that the nearest I have
been to a lathe is in the movies and picutres in books) is how do you start
turning something that is irregular in shape? Or even how do you turn a
round piece out of a square stock? Does it not do horrible things to the
cutting tool when it contacts only at the corners? Or is there a trick to
get the shape roughly round first somehow? I want to change the shape of the
brass cup but the initial attempt was somewhat discouraging.

Thanks for all your patience,

--
Michael Koblic,
Campbell River, BC

On Wed, 27 Aug 2008 19:16:27 -0700, "Michael Koblic"
wrote:



Are there any other suggestions ("Buy a lathe!" does not count)?

The other thing that puzzles me (and please note that the nearest I have
been to a lathe is in the movies and picutres in books) is how do you start
turning something that is irregular in shape? Or even how do you turn a
round piece out of a square stock? Does it not do horrible things to the
cutting tool when it contacts only at the corners? Or is there a trick to
get the shape roughly round first somehow? I want to change the shape of the
brass cup but the initial attempt was somewhat discouraging.

Thanks for all your patience,
A file works quite well, although slowly. For even slower metal
removal, use various forms of scraper (think single tooth file). For
coarser work, use hammer and chisel. If you want power assist, use
various grinders.
Gerry :-)}
London, Canada

On Aug 27, 10:16 pm, "Michael Koblic" wrote:

This is where I run into a bit of a problem - drilling the centre hole.

The candlestick was made in India, I am not sure how.

Probably cast. They had sophisticated metalworking skills when my
ancestors were still pounding rocks together. AFAIK it was all done in
small family shops with simple equipment and never grew into an
industry. Holtzapffel book IV, "Hand or Simple Turning" has the best
description I've seen of the traditional lathes of the Middle East and
Asia and the details of Western lathe development to 1880. You might
find the book very useful because the earlier versions were easier to
make than a modern lathe. "Simple" is relative; the Holtzapffels were
masters of the geometric or rose-engine lathe.

The Indian lathe pictured is made of two short stakes driven in the
ground with nails through them for centers. The tool rest is a stick
tied between them with extra supports as needed. The turner rests his
foot on the stick with the tool between his toes for coarse
positioning, and guides the end with his hand. A kid pulls the ends of
a string wrapped around the work to turn it back and forth. The Arab
lathe is only slightly fancier, a box close around the work. He has a
bow in one hand to turn the work with the string.

The lathe doesn't drive the work, it only supports it between centers.
You could turn the work directly with the motor and belt from an old
sewing machine, or a rubber caster wheel chucked in a hand drill. Be
creative, think of things as what they could do rather than what they
were meant for.

Your candlesticks may well be copied from a 2000 year old design cast
from a wooden pattern made this way. The manual skills of artisans
2000 years ago were easily equal to those today. Perhaps now those
people are surgeons rather than craftsmen.

As Watt quickly discovered, those artistic skills didn't apply to
making precision machinery.

Either way not very
well so the whole thing is a bit asymmetrical. I tried to determine the
centre of the end to drill a concentric hole but found it almost impossible.
In the end when hooked up to the live centre (which is loose on the drill
press table) the live centre was running around in a small circle whatever I
did.

Fix that. A large pointed setscrew held by nuts and washers might
work. If you make the head slide down as I suggested you can drill
another small hole in the base plate near the large one. You can align
them with a piece of wire in the chuck, bicycle spokes work well. Turn
it slowly by hand and try to make the circle the point describes small
by bending the wire. Move the head until that small circle is centered
on your center point. You can check it with a ruler.

Now I understand (I hope!) that on a lathe the live centre on the taistock
is lined up with the centre of the chuck on the head stock and the hole will
be drilled in the centre by default. Not having a lathe the best way I found
to drill centres in a round stock is to make a paper tube around it and use
a tight fitting transfer punch to mark the centre. This works fine if the
stock is cylindrical, not on a candle stick stem which is not.

Make a pair of upright Vee supports out of thin material. Rest the
candlestick on them at places you consider circular. Turn it while
holding a supported pencil against the end. The pencil will mark a
small circle around the rotational axis.

How well did you learn Euclidean geometry? It has methods for finding
the center of a circle or any other shape. One simple way is to guess
at the center, put one point of a compass there and see how far off it
is when you rotate it. Find where the compass is out furthest and
correct half the error by moving the center point, then readjust the
other point to the circle and recheck. For me this centers within
about 0.010".


I found a thread on this group from 2004 which provided several options of
which the only one viable in my situation would have been to use a 3-jaw
chuck to center under the drill press spindle and then substitute the centre
drill. And I am indeed looking for a cheap 3-jaw chuck.

Are there any other suggestions ("Buy a lathe!" does not count)?

The other thing that puzzles me (and please note that the nearest I have
been to a lathe is in the movies and picutres in books) is how do you start
turning something that is irregular in shape? Or even how do you turn a
round piece out of a square stock? Does it not do horrible things to the
cutting tool when it contacts only at the corners? Or is there a trick to
get the shape roughly round first somehow? I want to change the shape of the
brass cup but the initial attempt was somewhat discouraging.

Brass is a little tricky but it has been turned into exquisite shapes
like watch gears with hand-held tools for centuries. Heron of
Alexandria's ancient Greek gadget book used (brass?) sheet metal and
turned shafts as if they were common hardware items back then. His
book described a steam engine and also a vessel with a secret
compartment that appears to turn water into wine.

If you keep the tool's support close to the stock you avoid those
horrible things, otherwise the lathe may practice knife-throwing. I've
only done a little free-hand turning of aluminum and can't give you
much detailed help. Trying to work metal without machine tools is like
going everywhere on foot.

When I turn something from oak firewood I draw circles on the ends and
rough the blank close to them with a hatchet. On a real metal lathe
HSS bits stand up pretty well to interrupted cuts like turning a
square steel plate round, just take light cuts. This is one of the
jobs that makes a screw-on chuck hard to remove.

You can use that drill press center point to drill a centered hole
straight through a long piece.

Jim Wilkins
who -should- be out scraping paint.

On Aug 27, 10:16*pm, "Michael Koblic" wrote:
...And I am indeed looking for a cheap 3-jaw chuck....
Michael Koblic,

http://www.harborfreight.com/cpi/cta...temnumber=4486

The chuck mount is M12 x 1.0. It isn't too bad for the price.

On Wed, 27 Aug 2008 19:16:27 -0700, "Michael Koblic"
wrote:

The other thing that puzzles me (and please note that the nearest I have
been to a lathe is in the movies and picutres in books) is how do you start
turning something that is irregular in shape? Or even how do you turn a
round piece out of a square stock? Does it not do horrible things to the
cutting tool when it contacts only at the corners?

No, there is no trick, just that lathes are usually very heavy and
stiff (and have a lot of inertia) compared to the few thou of material
that will be removed on each hit..

What you're talking about is called an "interrupted cut" and it causes
vibration (and a sound that might be alarming the first time you hear
it) but it's not really a problem. You can turn a hex or square piece
of stock into round without problems, just don't feed too fast, and,
obviously, get the cutter outside for certain before starting or
you'll have a "crash" rather than an "interrupted cut").

Or is there a trick to
get the shape roughly round first somehow? I want to change the shape of the
brass cup but the initial attempt was somewhat discouraging.

Thanks for all your patience,
Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

"Michael Koblic" wrote in message
...
I picked up a few brass candle sticks in garage sales. I wanted to use one
for a brass sundial. It has a long stem and a cup for the candle. The stem
is irregular with some patterns on it.

I cut the stem off where I thought it would be just about right length for
the gnomon. I tried to "turn" it in my old drill press. It turned out not
so bad, I put a 10-32 thread on one end and tried to re-profile the rest
of it. It is about 5 cm long so I thought I would use the live center I
have for my sanding drums.
like this one:

http://www.leevalley.com/wood/page.a...02&cat=1,42500

This is where I run into a bit of a problem - drilling the centre hole.

The candlestick was made in India, I am not sure how. Either way not very
well so the whole thing is a bit asymmetrical. I tried to determine the
centre of the end to drill a concentric hole but found it almost
impossible. In the end when hooked up to the live centre (which is loose
on the drill press table) the live centre was running around in a small
circle whatever I did.

Now I understand (I hope!) that on a lathe the live centre on the taistock
is lined up with the centre of the chuck on the head stock and the hole
will be drilled in the centre by default. Not having a lathe the best way
I found to drill centres in a round stock is to make a paper tube around
it and use a tight fitting transfer punch to mark the centre. This works
fine if the stock is cylindrical, not on a candle stick stem which is not.

I found a thread on this group from 2004 which provided several options of
which the only one viable in my situation would have been to use a 3-jaw
chuck to center under the drill press spindle and then substitute the
centre drill. And I am indeed looking for a cheap 3-jaw chuck.

Are there any other suggestions ("Buy a lathe!" does not count)?

The other thing that puzzles me (and please note that the nearest I have
been to a lathe is in the movies and picutres in books) is how do you
start turning something that is irregular in shape? Or even how do you
turn a round piece out of a square stock? Does it not do horrible things
to the cutting tool when it contacts only at the corners? Or is there a
trick to get the shape roughly round first somehow? I want to change the
shape of the brass cup but the initial attempt was somewhat discouraging.

Thanks for all your patience,

--
Michael Koblic,
Campbell River, BC



An option to buyalathe is cobble together a facsimilie from surplus.

The surplus houses I've been to have mechanical components, or specif
purpose machines that have been retired.
We've bought lots of little machines for the components.

Sometimes you can get a huge pile of stuff for around $100us

also, scrounge your local scrap dealer for compnents.

For example, a front-wheel-drive auto spindle/bearing assembly is not far
removed from a lathe spindle.

Early metal turning was done on what were essentially wood lathes, with
similar turning tools.

Wood lathes are cheep, and/or easy to build.

On Aug 27, 8:16*pm, "Michael Koblic" wrote:
I picked up a few brass candle sticks in garage sales. I wanted to use one
for a brass sundial. It has a long stem and a cup for the candle. The stem
is irregular with some patterns on it.

I cut the stem off where I thought it would be just about right length for
the gnomon. I tried to "turn" it in my old drill press. It turned out not so
bad, I put a *10-32 thread on one end and tried to re-profile the rest of
it. It is about 5 cm long so I thought I would use the live center I have
for my sanding drums.
*like this one:

http://www.leevalley.com/wood/page.a...02&cat=1,42500

*This is where I run into a bit of a problem - drilling the centre hole..

The candlestick was made in India, I am not sure how. Either way not very
well so the whole thing is a bit asymmetrical. I tried to determine the
centre of the end to drill a concentric hole but found it almost impossible.
In the end when hooked up to the live centre (which is loose on the drill
press table) the live centre was running around in a small circle whatever I
did.

Now I understand (I hope!) that on a lathe the live centre on the taistock
is lined up with the centre of the chuck on the head stock and the hole will
be drilled in the centre by default. Not having a lathe the best way I found
to drill centres in a round stock is to make a paper tube around it and use
a tight fitting transfer punch to mark the centre. This works fine if the
stock is cylindrical, not on a candle stick stem which is not.

I found a thread on this group from 2004 which provided several options of
which the only one viable in my situation would have been to use a 3-jaw
chuck to center under the drill press spindle and then substitute the centre
drill. And I am indeed looking for a cheap 3-jaw chuck.

Are there any other suggestions ("Buy a lathe!" does not count)?

The other thing that puzzles me (and please note that the nearest I have
been to a lathe is in the movies and picutres in books) is how do you start
turning something that is irregular in shape? Or even how do you turn a
round piece out of a square stock? Does it not do horrible things to the
cutting tool when it contacts only at the corners? Or is there a trick to
get the shape roughly round first somehow? I want to change the shape of the
brass cup but the initial attempt was somewhat discouraging.

Thanks for all your patience,

--
Michael Koblic,
Campbell River, BC

Marking rough castings for centerdrilling used to be a must-have
skill. My 1905 Audel's shows one way. You use an oddleg caliper, one
leg is curved like normal outside calipers, the other is straight(and
sharp). Set the thing a little more than half-way to the other side
and draw an arc off the edge. Rotate about 90 degrees and repeat,
repeat 2 more times and and you'll have a rough box shape marked out.
Use a machinist's rule across the diagonal and scribe a line.
Repeat. Centerpunch the intersection and it should be close enough to
center. Drill using a center drill. Repeat on the other end.

As far as interrupted cuts, castings were snagged off using chisels
and grinders so they weren't really too far out. With iron castings,
you have to make sure you get under the hard skin on the first cut,
otherwise the tool edge disappears. With brass, you just have to make
sure you aren't cutting sponge with embedded sand. Slow speeds and
feeds help if the lathe isn't a 2 ton heavyweight. Once the
interrupted cut disappears, speed can be increased.

Stan

"Gerald Miller" wrote in message
...
A file works quite well, although slowly. For even slower metal
removal, use various forms of scraper (think single tooth file). For
coarser work, use hammer and chisel. If you want power assist, use
various grinders.

For this job symmetry was the main requirement. I find it very hard to file
irregular-shaped bars to make them into cylinders.
I tried the "reverse lathe" method using a bench sander. However, the part
is quite small and fingers are definitely an issue. I tried chucking it but
the set up was suboptimal and I nearly killed the part outright. Stopped
just in time.

I just took apart a very old Sears cordless drill and will try again
tomorrow with a better chucking arrangement.

"Jim Wilkins" wrote in message
...
The candlestick was made in India, I am not sure how.

Probably cast.

On close inspection I suspect you are right.

The lathe doesn't drive the work, it only supports it between centers.
You could turn the work directly with the motor and belt from an old
sewing machine, or a rubber caster wheel chucked in a hand drill. Be
creative, think of things as what they could do rather than what they
were meant for.

I do. Some "thoughts" would make your hair stand on end...:-)

I tried to determine the
centre of the end to drill a concentric hole but found it almost
impossible.
In the end when hooked up to the live centre (which is loose on the drill
press table) the live centre was running around in a small circle
whatever I
did.

Fix that. A large pointed setscrew held by nuts and washers might
work. If you make the head slide down as I suggested you can drill
another small hole in the base plate near the large one. You can align
them with a piece of wire in the chuck, bicycle spokes work well. Turn
it slowly by hand and try to make the circle the point describes small
by bending the wire. Move the head until that small circle is centered
on your center point. You can check it with a ruler.

I have re-read this about six times and I am not altogether sure that I
understood: I have no difficulty aligning the centre point of the live
centre with the centre of the spindle. However, when I chuck the gnomon and
put the opposite end on the live centre (using the supposedly centre hole I
drilled), the gnomon, being slightly out of alignment, moves the live centre
around.


Now I understand (I hope!) that on a lathe the live centre on the
taistock
is lined up with the centre of the chuck on the head stock and the hole
will
be drilled in the centre by default. Not having a lathe the best way I
found
to drill centres in a round stock is to make a paper tube around it and
use
a tight fitting transfer punch to mark the centre. This works fine if the
stock is cylindrical, not on a candle stick stem which is not.

Make a pair of upright Vee supports out of thin material. Rest the
candlestick on them at places you consider circular. Turn it while
holding a supported pencil against the end. The pencil will mark a
small circle around the rotational axis.

How well did you learn Euclidean geometry? It has methods for finding
the center of a circle or any other shape. One simple way is to guess
at the center, put one point of a compass there and see how far off it
is when you rotate it. Find where the compass is out furthest and
correct half the error by moving the center point, then readjust the
other point to the circle and recheck. For me this centers within
about 0.010".

The euclid works if the cross-section is truly circular. In the case of this
piece it is not. Furthermore, the smaller the diameter (in ,my case about
1/4") the more difficult the method, even if the cross-section is truly
circular. I have used this:

http://www.leevalley.com/wood/page.a...65&cat=1,42936
(the centre-finding head)

but the transfer punch/paper roll method beats it every time particularly
for small parts. There is this:

http://www.victornet.com/cgi-bin/vic...uares% 3A1242

but I have never used it and wonder if it improves accuracy over the other
one. The other issue with very small parts is to actually hit the right spot
with a centre punch: I have been using a lamp with a magnifying lens and
even that is not particularly great. I am thinking of getting this:

http://www.leevalley.com/wood/page.a...=1,42936,50298

Maybe with a centre drill you do not need to punch? Am I right in that?



I found a thread on this group from 2004 which provided several options
of
which the only one viable in my situation would have been to use a 3-jaw
chuck to center under the drill press spindle and then substitute the
centre
drill. And I am indeed looking for a cheap 3-jaw chuck.

Are there any other suggestions ("Buy a lathe!" does not count)?

The other thing that puzzles me (and please note that the nearest I have
been to a lathe is in the movies and picutres in books) is how do you
start
turning something that is irregular in shape? Or even how do you turn a
round piece out of a square stock? Does it not do horrible things to the
cutting tool when it contacts only at the corners? Or is there a trick to
get the shape roughly round first somehow? I want to change the shape of
the
brass cup but the initial attempt was somewhat discouraging.

Brass is a little tricky but it has been turned into exquisite shapes
like watch gears with hand-held tools for centuries. Heron of
Alexandria's ancient Greek gadget book used (brass?) sheet metal and
turned shafts as if they were common hardware items back then. His
book described a steam engine and also a vessel with a secret
compartment that appears to turn water into wine.

If you keep the tool's support close to the stock you avoid those
horrible things, otherwise the lathe may practice knife-throwing. I've
only done a little free-hand turning of aluminum and can't give you
much detailed help. Trying to work metal without machine tools is like
going everywhere on foot.

I was basically using files supported by a wooden block as close as possible
to the piece. I am not brave enough yet to try a proper cutting tool.

I gotta get more space on Flickr - it is so much easier to show pictures.
Anyway, thanks for the advice.

--
Michael Koblic,
Campbell River, BC

"Jim Wilkins" wrote in message
...
On Aug 27, 10:16 pm, "Michael Koblic" wrote:
...And I am indeed looking for a cheap 3-jaw chuck....
Michael Koblic,

http://www.harborfreight.com/cpi/cta...temnumber=4486

The chuck mount is M12 x 1.0. It isn't too bad for the price.

****Thanks, but AFAIK they do not ship to Canada. I have a few under
surveillance on EBay.

"Jon" wrote in message
news:u4ztk.949$p72.578@trnddc05...
An option to buyalathe is cobble together a facsimilie from surplus.

The surplus houses I've been to have mechanical components, or specif
purpose machines that have been retired.
We've bought lots of little machines for the components.

Sometimes you can get a huge pile of stuff for around $100us

also, scrounge your local scrap dealer for compnents.

For example, a front-wheel-drive auto spindle/bearing assembly is not far
removed from a lathe spindle.

Early metal turning was done on what were essentially wood lathes, with
similar turning tools.

Wood lathes are cheep, and/or easy to build.

I am slowly acquiring a pile of stuff. Right now the closest I am getting is
the old drill press. I am wondering if simply mounting it on its side and
improvising some sort of tailstock in the place of the base might be a good
idea...

wrote in message
...
Marking rough castings for centerdrilling used to be a must-have
skill. My 1905 Audel's shows one way. You use an oddleg caliper, one
leg is curved like normal outside calipers, the other is straight(and
sharp). Set the thing a little more than half-way to the other side
and draw an arc off the edge. Rotate about 90 degrees and repeat,
repeat 2 more times and and you'll have a rough box shape marked out.
Use a machinist's rule across the diagonal and scribe a line.
Repeat. Centerpunch the intersection and it should be close enough to
center. Drill using a center drill. Repeat on the other end.

***I believe it is called a hermaphrodite caliper. I have one of those but
on small parts it is quite useless. I have gone into this in my reply to Jim
Wilkins. I did like his idea of spinning the part and letting a pencil draw
a circle about the rotational axis the other end. I have not tried it yet.

As far as interrupted cuts, castings were snagged off using chisels
and grinders so they weren't really too far out. With iron castings,
you have to make sure you get under the hard skin on the first cut,
otherwise the tool edge disappears. With brass, you just have to make
sure you aren't cutting sponge with embedded sand.

***That would be the residue of casting?

Thanks

--
Michael Koblic,
Campbell River, BC

On Aug 28, 11:51 pm, "Michael Koblic" wrote:
"Jim Wilkins" wrote in message

Some "thoughts" would make your hair stand on end...:-)

What little hair is left... :-( (that's a beard, I grow it wherever
I still can)
I've run the model shop in electronics companies and thus dealt with
the creative misadventures of clever engineers with no practical
experience.

In the end when hooked up to the live centre (which is loose on the drill
press table) the live centre was running around in a small circle
whatever I did.

A large pointed setscrew held by nuts and washers might work.

Setscrew pointed upward for the center, nuts and washers to hold it
tight in the hole.

...You can align them with a piece of wire in the chuck,...

I have re-read this about six times and I am not altogether sure that I
understood: I have no difficulty aligning the centre point of the live
centre with the centre of the spindle. However, when I chuck the gnomon and
put the opposite end on the live centre (using the supposedly centre hole I
drilled), the gnomon, being slightly out of alignment, moves the live centre
around.

http://www.lindsaybks.com/bks/advmach/index.html

Don't be put off by its age. Production techniques may have improved
dramatically since then but manual lathe operations are still the
same.

If the chuck doesn't hold the part straight you mount it between
centers and drive it with a dog.
I think a 4-sided pyramidal point held in the drill chuck is enough to
drive brass without a dog if you take light cuts. You don't need to
make the point run perfectly true as long as you mark it so you can
remove and replace the work.

How well did you learn Euclidean geometry?
The euclid works if the cross-section is truly circular.

There are constructions for centering even a triangle.
A quick shortcut I often use is to center a thin 6" flex rule across
the work by equalizing the end readings.
For example one end is at 1-1/8", the other at 4-7/8".
Hold a scriber point against the work at the 3" mark, then turn the
rule 90 degrees and repeat.
I like the style of graduations called 3R for this.

but the transfer punch/paper roll method beats it every time particularly
for small parts.

That's a good idea I hadn't seen before. Then again I have a collet
lathe which is the perfect machine for making small round parts. Mine
would be a little more perfect if it hadn't been abused in trade
school. A small lathe with a 3-jaw chuck is close. http://www.mini-lathe.com/

Maybe with a centre drill you do not need to punch? Am I right in that?

See the center/spot/stub drill thread. With less rigid equipment like
your drill press and my 50-year-old milling machine you have to learn
what works and what doesn't. The punch mark is to align the drill bit
with your hand layout since it's very difficult to position the center
of the drill bit directly.

Jim Wilkins

"Jim Wilkins" wrote in message
...
On Aug 28, 11:51 pm, "Michael Koblic" wrote:
"Jim Wilkins" wrote in message

Some "thoughts" would make your hair stand on end...:-)

What little hair is left... :-( (that's a beard, I grow it wherever
I still can)
I've run the model shop in electronics companies and thus dealt with
the creative misadventures of clever engineers with no practical
experience.

Judging from your e-mail address you will understand how electronics were
done by amateurs before the advent of the black boxes. Except we did not
have black boxes: we had Wehrmacht surplus. And ingenuity. And fire
insurance...


In the end when hooked up to the live centre (which is loose on the
drill
press table) the live centre was running around in a small circle
whatever I did.

A large pointed setscrew held by nuts and washers might work.

Setscrew pointed upward for the center, nuts and washers to hold it
tight in the hole.

I see. I could actually clamp the "live center" in a drill press vise and
position it. I was just thinking what kind of rotation will happen to the
piece if its so bent that it moves the centre around when *not* clamped. I
guess it will find a way...

...You can align them with a piece of wire in the chuck,...

I have re-read this about six times and I am not altogether sure that I
understood: I have no difficulty aligning the centre point of the live
centre with the centre of the spindle. However, when I chuck the gnomon
and
put the opposite end on the live centre (using the supposedly centre hole
I
drilled), the gnomon, being slightly out of alignment, moves the live
centre
around.

http://www.lindsaybks.com/bks/advmach/index.html

Don't be put off by its age. Production techniques may have improved
dramatically since then but manual lathe operations are still the
same.

For that I thank you. In fact I have been actively looking for older texts
which are more in keeping with what I am doing. I think I mentioned the old
blacksmith book with wooden bearings etc. He goes into lathes a bit but not
in enough detail (where, as far as I am concerned, is where the God is).

I am waiting for my first order from Smartflix so I can see these things
actually happening. They have some extensive courses on milling and lathing.
If it works out renting from them I should move forward more quickly. In any
case, I have ordered the book you recommended.

If the chuck doesn't hold the part straight you mount it between
centers and drive it with a dog.
I think a 4-sided pyramidal point held in the drill chuck is enough to
drive brass without a dog if you take light cuts. You don't need to
make the point run perfectly true as long as you mark it so you can
remove and replace the work.

Does the dog not object? Juvenile humour aside, now I have to study how to
use a dog! I thought a dog was a sort of bent thing which held parts to a
face plate if you did not have a chuck...

How well did you learn Euclidean geometry?
The euclid works if the cross-section is truly circular.

There are constructions for centering even a triangle.
A quick shortcut I often use is to center a thin 6" flex rule across
the work by equalizing the end readings.
For example one end is at 1-1/8", the other at 4-7/8".
Hold a scriber point against the work at the 3" mark, then turn the
rule 90 degrees and repeat.
I like the style of graduations called 3R for this.

3" yes. 0.3" no...

but the transfer punch/paper roll method beats it every time particularly
for small parts.

That's a good idea I hadn't seen before. Then again I have a collet
lathe which is the perfect machine for making small round parts. Mine
would be a little more perfect if it hadn't been abused in trade
school. A small lathe with a 3-jaw chuck is close.
http://www.mini-lathe.com/

Ha! You heard it here first! I have never seen it myself elsewhere, it just
came to me when I was trying to drill centre hole in the end of a 3/16"
copper rivet to stick on the end of my gnomon. I had to make another jig to
hold the rivet in the drill press vise but it works just fine.


Maybe with a centre drill you do not need to punch? Am I right in that?

See the center/spot/stub drill thread. With less rigid equipment like
your drill press and my 50-year-old milling machine you have to learn
what works and what doesn't. The punch mark is to align the drill bit
with your hand layout since it's very difficult to position the center
of the drill bit directly.

I have been following that thread - and I was not sure. I bought a centre
drill and promptly broke one end. The other end worked well, but I used a
punch. I believe you have to run them quite fast.

As an update: I bought a $17 Jacobs 1/2" chuck today and was able to chuck
one of the brass cups in it safely and tidied it up by the "reverse lathe"
method of holding it and rotating it by hand against a 220-grit belt sander.
I even found 3 1/2"-20 bolts of different lengths and am thinking of making
a jig to drill concentric holes along the lines recommended in the 2004
thread (there they used a wooden block on its side to drill a centre hole in
a long rod - rather ingenious I thought).

--
Michael Koblic,
Campbell River, BC
-ex OL1AGS
-ex G4GIU
-ex GW4GIU
-VE7EQG (QRT 7 years)

On 2008-08-30, Michael Koblic wrote:

"Jim Wilkins" wrote in message
...
On Aug 28, 11:51 pm, "Michael Koblic" wrote:
"Jim Wilkins" wrote in message

[ ... ]

A large pointed setscrew held by nuts and washers might work.

Setscrew pointed upward for the center, nuts and washers to hold it
tight in the hole.

I see. I could actually clamp the "live center" in a drill press vise and
position it.

If you add a V block to the vise to keep things from shifting.
upright round objects are difficult to clamp reliably in a vise, but add
a V-block and you can do a better job with a cylindrical item. However
a live center typicaly has a Morse taper shank, so you'll need some
extra tricks to make up for the taper itself.

I was just thinking what kind of rotation will happen to the
piece if its so bent that it moves the centre around when *not* clamped. I
guess it will find a way...

:-)

[ ... ]

http://www.lindsaybks.com/bks/advmach/index.html

Don't be put off by its age. Production techniques may have improved
dramatically since then but manual lathe operations are still the
same.

For that I thank you. In fact I have been actively looking for older texts
which are more in keeping with what I am doing. I think I mentioned the old
blacksmith book with wooden bearings etc. He goes into lathes a bit but not
in enough detail (where, as far as I am concerned, is where the God is).

I am waiting for my first order from Smartflix so I can see these things
actually happening. They have some extensive courses on milling and lathing.

Hopefully, they will also tell you that while you are using a
lahte, you are *not* "lathing", but rather "turning". :-)

If it works out renting from them I should move forward more quickly. In any
case, I have ordered the book you recommended.

If the chuck doesn't hold the part straight you mount it between
centers and drive it with a dog.
I think a 4-sided pyramidal point held in the drill chuck is enough to
drive brass without a dog if you take light cuts. You don't need to
make the point run perfectly true as long as you mark it so you can
remove and replace the work.

Does the dog not object? Juvenile humour aside, now I have to study how to
use a dog! I thought a dog was a sort of bent thing which held parts to a
face plate if you did not have a chuck...

It is used with a face plate, to impart rotation to a workpiece
suspended between centers. The one in the headstock spindle rotates,
but it does not have enough contact area to really drive the workpiece,
so the dog is clamped onto a part of the workpiece which you are not
(currently) changing, and its tail is driven by a slot in the faceplate
(if a bent-tail dog), or by a bolt through the faceplate (if a
straight tail dog). These do not wag. :-)

If you are trying to drive something with a drill chuck which
has a poor enough finish on the end so you can't clamp it and prevent it
from wobbling, then you clamp the drill chuck onto some steel rod, take
a file to it while it is rotating to form it to a point (60 degree
angle), and use this to hold the upper end of your workpiece. You will
then need to clamp a bent-tail dog onto the upper end of the workpiece,
and a collar of some sort around the drill chuck to drive the dog's
tail.

Another thing to worry about is that most drill presses don't go
slow enough, and if the workpiece, collar, and dog are not fairly well
balanced, the drill press will try to walk around the floor (or the
workbench, if it is a benchtop drill press).

[ ... ]

That's a good idea I hadn't seen before. Then again I have a collet
lathe which is the perfect machine for making small round parts. Mine
would be a little more perfect if it hadn't been abused in trade
school. A small lathe with a 3-jaw chuck is close.
http://www.mini-lathe.com/

Ha! You heard it here first! I have never seen it myself elsewhere, it just
came to me when I was trying to drill centre hole in the end of a 3/16"
copper rivet to stick on the end of my gnomon. I had to make another jig to
hold the rivet in the drill press vise but it works just fine.

The ability to make fixtures is an important one in any kind of
metalwork, and some woodwork as well.


Maybe with a centre drill you do not need to punch? Am I right in that?

See the center/spot/stub drill thread. With less rigid equipment like
your drill press and my 50-year-old milling machine you have to learn
what works and what doesn't. The punch mark is to align the drill bit
with your hand layout since it's very difficult to position the center
of the drill bit directly.

I have been following that thread - and I was not sure. I bought a centre
drill and promptly broke one end. The other end worked well, but I used a
punch. I believe you have to run them quite fast.

How large a diameter of center drill? The proper speed for one
is a function of its maximum diameter -- and the metal into which you
are drilling.

To avoid snapping off the point, you need a way to prevent the
workpiece from tilting in the drill press. Also, a proper
coolant/cutting fluid would help them to survive. But center drills
(like all drills) are "consumables" so keep spares on hand.

Good 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 ---

"DoN. Nichols" wrote in message
...
If you add a V block to the vise to keep things from shifting.
upright round objects are difficult to clamp reliably in a vise, but add
a V-block and you can do a better job with a cylindrical item. However
a live center typicaly has a Morse taper shank, so you'll need some
extra tricks to make up for the taper itself.

My vise has a sort of vertical v-block incorporated. My "live centre" really
only remotely resembles a proper lathe live centre.


I was just thinking what kind of rotation will happen to the
piece if its so bent that it moves the centre around when *not* clamped.
I
guess it will find a way...

It is used with a face plate, to impart rotation to a workpiece
suspended between centers. The one in the headstock spindle rotates,
but it does not have enough contact area to really drive the workpiece,
so the dog is clamped onto a part of the workpiece which you are not
(currently) changing, and its tail is driven by a slot in the faceplate
(if a bent-tail dog), or by a bolt through the faceplate (if a
straight tail dog). These do not wag. :-)

For that you need a wiggler?

If you are trying to drive something with a drill chuck which
has a poor enough finish on the end so you can't clamp it and prevent it
from wobbling, then you clamp the drill chuck onto some steel rod, take
a file to it while it is rotating to form it to a point (60 degree
angle), and use this to hold the upper end of your workpiece. You will
then need to clamp a bent-tail dog onto the upper end of the workpiece,
and a collar of some sort around the drill chuck to drive the dog's
tail.

OK, now I found some nice pictures and I understand it. Sort of.


Another thing to worry about is that most drill presses don't go
slow enough, and if the workpiece, collar, and dog are not fairly well
balanced, the drill press will try to walk around the floor (or the
workbench, if it is a benchtop drill press).

At this point using the canine arrangement on my drill press fills me with a
sense of dread. Also, the parts I am turning are very small, so a really
small dog would be required. A chihuahua...

How large a diameter of center drill? The proper speed for one
is a function of its maximum diameter -- and the metal into which you
are drilling.

1/8"


To avoid snapping off the point, you need a way to prevent the
workpiece from tilting in the drill press. Also, a proper
coolant/cutting fluid would help them to survive. But center drills
(like all drills) are "consumables" so keep spares on hand.

I swear the first one snapped just by me looking at it...

I just took apart a very old Sears cordless drill and liberated a 12V motor
as well as a 3/8" chuck and a whole bunch of cool little gears. Also I found
an old 12V motor with some strange reduction gear which, many years ago was
going to be a pottery wheel for kids. Some of this stuff has got to be
useful even though 12V is not exactly ideal.

If it was straightforward it would not be fun...

--
Michael Koblic,
Campbell River, BC

On Aug 29, 10:06 pm, "Michael Koblic" wrote:
"Jim Wilkins" wrote in message
On Aug 28, 11:51 pm, "Michael Koblic" wrote:
"Jim Wilkins" wrote in message

Judging from your e-mail address you will understand how electronics were
done by amateurs before the advent of the black boxes. Except we did not
have black boxes: we had Wehrmacht surplus. And ingenuity. And fire
insurance...

We had plenty of US mil-surp gear to play with too. The aircraft stuff
often ran on 400 Hz AC and operated on 225-400 MHz which is military-
only here.

I used to have a working copy of a German aircraft-detection radar
transmitter from 1931(?) sitting on my Mac's monitor. It consisted of
a high-voltage transformer and a spark gap. The two spark gap
electrodes formed a dipole about 100mm long. There was enough lead
wire connected to it that I wouldn't predict the frequency and I
expect it was broadly tuned, but it could have been over 1 GHz. When I
rescued it from a lab I was closing down it was in an aquarium tank
because it was so dangerous. I removed the power cord. Spark gap
transmitters are illegal to operate now anyway.

As I understand it, the receiver was shielded from the transmitter and
only received the CW signal when it reflected off an airplane.
Detecting the audio-frequency Doppler shift in the return seems
unlikely for biplane speeds and spark-gap bandwidth and it goes away
as the plane approaches.

In "The Wizard War" Dr Jones wrote that early '40's German field radar
transmitters were as stable in frequency as the best British lab
standards, apparently because they could grind quartz crystals better.
He certainly had a lot of respect for German equipment. Then again,
the British chose to use American aircraft radios rather than their
own. As with Russia and Japan their theoretical and lab work was
excellent but they had trouble mass producing it.

but the transfer punch/paper roll method beats it every time particularly
for small parts.

That's a good idea I hadn't seen before.

Ha! You heard it here first!

The traditional center punching tool looks like a funnel with the
center punch sliding in the spout.

These are a gold mine of information;
http://www.amazon.com/Hand-Simple-Tu...s-Practice/dp/
0486264289/ref=sr_1_3?ie=UTF8&s=books&qid=1220099472&sr=1-3
If the link is broken, Google for "Holtzapffel"

The yellow one concentrates on turning and should answer your
questions very well, the red one is about hand tools and the history
of screw threads. I don't have the other books yet. They describe
Victorian-era technology in exquisite detail from a master toolmaker's
perspective and often give the inventor of our common tools, for
example Mr. Hale registered the centering square in 1862, Holtzapffel
and Deyerlein began making 3-jaw self-centering lathe chucks in 1811.

Like anything German they are ignored in most English-language history
books although they worked in London since 1787 and helped train
Whitworth. "English and American Tool Builders" gives them only a
paragraph. The Holtzappfel books complement that biographical one by
showing their work.

Jim Wilkins

On Aug 30, 10:48*am, Jim Wilkins wrote:
....
http://www.amazon.com/Hand-Simple-Tu...s-Practice/dp/
0486264289/ref=sr_1_3?ie=UTF8&s=books&qid=1220099472&sr=1-3

It worked when I copied both halves into the address bar separately.

On Sat, 30 Aug 2008 08:45:45 -0700, Jim Wilkins wrote:
On Aug 30, 10:48Â*am, Jim Wilkins wrote: ...
http://www.amazon.com/Hand-Simple-Tu...s-Practice/dp/
0486264289/ref=sr_1_3?ie=UTF8&s=books&qid=1220099472&sr=1-3

It worked when I copied both halves into the address bar separately.

I guess you are talking about how to deal with a URL that
is split across lines. The way I usually deal with URL's
like that is to ignore them and go on to the next post.

But if I actually want to see them I could highlight all
of the URL and paste it into firefox's address bar, then
delete extraneous characters. For example, if I highlighted
from "http:" through "=1-3" in the above and pasted it, the
address bar would look like it started off with " 048" (ie
the newline disappeared the first part) and I then could
put the cursor on the blank, press backspace 4 times, and
Enter to see the web page.

That's what I could do; what I actually do in such a case is
highlight all of the URL, then click a button for a script that
strips out newlines from selection and sends it off to firefox
to display. (In a case like the above I'd still have to delete
some extraneous characters in the address bar.)

-jiw

On 2008-08-30, Michael Koblic wrote:

"DoN. Nichols" wrote in message
...
If you add a V block to the vise to keep things from shifting.
upright round objects are difficult to clamp reliably in a vise, but add
a V-block and you can do a better job with a cylindrical item. However
a live center typically has a Morse taper shank, so you'll need some
extra tricks to make up for the taper itself.

My vise has a sort of vertical v-block incorporated. My "live centre" really
only remotely resembles a proper lathe live centre.

O.K. The v-groove in the vise (likely not a very deep one, but
something to help) is a start. Ideal depth of V-groove would be such
that the two sides of the 'V' are tangent to the diameter of the thing
being held. If it is shallow enough so the tops of the V touch the
circumference of the workpiece it will cut grooves into the workpiece
and will not be as good a grip. Of course, some vises (e.g. toolmakers
vises) have deeper grooves than others do.

As for your "live center" -- is it at least a pointed part held
in bearings so it is free to rotate? That is a start. If it is not
free to rotate, then it is just a center, not a *live* center.

Of course -- way back before bearing mounted centers in the
tailstock became common, the center in the headstock was called "live"
(because it rotated), and the one in the tailstock was called "dead"
because it did not. And the point of contact between the tailstock
center and the workpiece was lubricated with "white lead" (a lead oxide,
IIRC) -- something considered a hazardous material these days. :-) There
was typically a small well in the tailstock casting, and a plug which
would dip out some and could apply it to the center/hole interface.


I was just thinking what kind of rotation will happen to the
piece if its so bent that it moves the centre around when *not* clamped.
I
guess it will find a way...

It is used with a face plate, to impart rotation to a workpiece
suspended between centers. The one in the headstock spindle rotates,
but it does not have enough contact area to really drive the workpiece,
so the dog is clamped onto a part of the workpiece which you are not
(currently) changing, and its tail is driven by a slot in the faceplate
(if a bent-tail dog), or by a bolt through the faceplate (if a
straight tail dog). These do not wag. :-)

For that you need a wiggler?

Well ... actually a "wiggler" is an indicator used for moving
centers of the workpiece over/under the axis of the lathe, mill, or
drill press spindles.

If you are trying to drive something with a drill chuck which
has a poor enough finish on the end so you can't clamp it and prevent it
from wobbling, then you clamp the drill chuck onto some steel rod, take
a file to it while it is rotating to form it to a point (60 degree
angle), and use this to hold the upper end of your workpiece. You will
then need to clamp a bent-tail dog onto the upper end of the workpiece,
and a collar of some sort around the drill chuck to drive the dog's
tail.

OK, now I found some nice pictures and I understand it. Sort of.

Good -- pictures do help a lot. You know -- there are
downloadable PDF files of various old books (out of copyright) which are
very good things to have for what you are trying to do -- or for anyone
with an old manual lathe, mill, and other such tools.


Another thing to worry about is that most drill presses don't go
slow enough, and if the workpiece, collar, and dog are not fairly well
balanced, the drill press will try to walk around the floor (or the
workbench, if it is a benchtop drill press).

At this point using the canine arrangement on my drill press fills me with a
sense of dread. Also, the parts I am turning are very small, so a really
small dog would be required. A chihuahua...

I've got one of those -- a dog which came with my Unimat SL-1000
back around 1970 or so. Hmm ... a pity that Unimat of that vintage are
now being treated as collectors items on eBay. Otherwise, it could be a
reasonable lathe for making your gnomen, albeit a bit small for turning
the scale ring (whatever it is called).

Yes. If you had a lathe, you could make a disc shaped dog, with
a disc to hold the "tail" and a setscrew from the other end, and you
could add bolts to the side opposite the dog to balance the tail.

You could also make something which would clamp on the bottom
section of the chuck (after it was tightened) which had two or three
evenly spaced slots to engage the dog tail -- and not need to worry
about its balance. This would leave only the workpiece itself, and if
it is as small as you say, it probably would not have any significant
problems with balance.

*But* -- if you had a lathe, you would not need to do all of
this anyway. :-)

How large a diameter of center drill? The proper speed for one
is a function of its maximum diameter -- and the metal into which you
are drilling.

1/8"

O.K. Yes, that would want to run fairly fast. 2000 RPM would
be only slightly over 65 SFM (Surface Feet per Minute -- the measure
used for determining the speed of the workpiece/tool interface. (take
the diameter in inches, multiply by Pi, divide by 12 to give the
circumference in feet, and divide that into the RPM. That is a fairly
conservative speed for HSS (High Speed Steel) in brass.

To avoid snapping off the point, you need a way to prevent the
workpiece from tilting in the drill press. Also, a proper
coolant/cutting fluid would help them to survive. But center drills
(like all drills) are "consumables" so keep spares on hand.

I swear the first one snapped just by me looking at it...

It feels like that sometimes. Were you using it in a drill
press, or in a hand drill? The drill press is the better bet. And
don't just keep pushing it in -- go a little way in, then back the
spindle up to let chips clear, then in again, etc. Normally you don't
need cutting fluids on a free-machining brass, but I don't know what the
characteristics of the cast brass which you are working with might be.
I wonder whether it could be a bronze? Not likely, as those are more
expensive, but they are tougher alloys.

I just took apart a very old Sears cordless drill and liberated a 12V motor
as well as a 3/8" chuck and a whole bunch of cool little gears. Also I found
an old 12V motor with some strange reduction gear which, many years ago was
going to be a pottery wheel for kids. Some of this stuff has got to be
useful even though 12V is not exactly ideal.

An old automobile battery and a battery charger to keep it near
full charge and you should be fine. And that would be a lot cheaper
than a lab power supply of sufficient capacity to handle your tools.
(Hmm ... if it is small enough, perhaps a motorcycle battery would be
sufficient.

If it was straightforward it would not be fun...

:-)

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 ---

----- Original Message -----
From: "DoN. Nichols"
Newsgroups: rec.crafts.metalworking
Sent: Saturday, August 30, 2008 1:47 PM
Subject: Red-neck lathe v2.0


O.K. The v-groove in the vise (likely not a very deep one, but
something to help) is a start. Ideal depth of V-groove would be such
that the two sides of the 'V' are tangent to the diameter of the thing
being held. If it is shallow enough so the tops of the V touch the
circumference of the workpiece it will cut grooves into the workpiece
and will not be as good a grip. Of course, some vises (e.g. toolmakers
vises) have deeper grooves than others do.

So far so good, but I have also a couple of bigger v-blocks if need be.


As for your "live center" -- is it at least a pointed part held
in bearings so it is free to rotate? That is a start. If it is not
free to rotate, then it is just a center, not a *live* center.

It does that.

For that you need a wiggler?

Well ... actually a "wiggler" is an indicator used for moving
centers of the workpiece over/under the axis of the lathe, mill, or
drill press spindles.

That was supposed to be a joke...

Good -- pictures do help a lot. You know -- there are
downloadable PDF files of various old books (out of copyright) which are
very good things to have for what you are trying to do -- or for anyone
with an old manual lathe, mill, and other such tools.

I am beginning to find them. It seems tricky. You do the search one way and
nothing happens, you do it another and out they pop..


*But* -- if you had a lathe, you would not need to do all of
this anyway. :-)

And there is the nub of the matter...

O.K. Yes, that would want to run fairly fast. 2000 RPM would
be only slightly over 65 SFM (Surface Feet per Minute -- the measure
used for determining the speed of the workpiece/tool interface. (take
the diameter in inches, multiply by Pi, divide by 12 to give the
circumference in feet, and divide that into the RPM. That is a fairly
conservative speed for HSS (High Speed Steel) in brass.

I run most of my drills slower than the book speed. I have not find a
convincing argument that it is harmful to the tools. The centre drills seem
to be an exception - they snap at lower speeds.

I swear the first one snapped just by me looking at it...

It feels like that sometimes. Were you using it in a drill
press, or in a hand drill? The drill press is the better bet. And
don't just keep pushing it in -- go a little way in, then back the
spindle up to let chips clear, then in again, etc. Normally you don't
need cutting fluids on a free-machining brass, but I don't know what the
characteristics of the cast brass which you are working with might be.
I wonder whether it could be a bronze? Not likely, as those are more
expensive, but they are tougher alloys.

Garage sale candlesticks - generic brass all the way. Very soft.


I just took apart a very old Sears cordless drill and liberated a 12V
motor
as well as a 3/8" chuck and a whole bunch of cool little gears. Also I
found
an old 12V motor with some strange reduction gear which, many years ago
was
going to be a pottery wheel for kids. Some of this stuff has got to be
useful even though 12V is not exactly ideal.

An old automobile battery and a battery charger to keep it near
full charge and you should be fine. And that would be a lot cheaper
than a lab power supply of sufficient capacity to handle your tools.
(Hmm ... if it is small enough, perhaps a motorcycle battery would be
sufficient.

I have a couple of power supplies - one should give steady 5 amps which as
it turns out may not be enough. The other one should give 20 amps. I have
not tried that one yet.

Note to self: Do not take motors apart without securing the brushes first! A
good way to avoid doing anything productive for an hour...

Michael Koblic,
Campbell River, BC

"Jim Wilkins" wrote in message
...
....

We had plenty of US mil-surp gear to play with too. The aircraft stuff
often ran on 400 Hz AC and operated on 225-400 MHz which is military-
only here.

I used to have a working copy of a German aircraft-detection radar
transmitter from 1931(?) sitting on my Mac's monitor. It consisted of
a high-voltage transformer and a spark gap. The two spark gap
electrodes formed a dipole about 100mm long. There was enough lead
wire connected to it that I wouldn't predict the frequency and I
expect it was broadly tuned, but it could have been over 1 GHz. When I
rescued it from a lab I was closing down it was in an aquarium tank
because it was so dangerous. I removed the power cord. Spark gap
transmitters are illegal to operate now anyway.

As I understand it, the receiver was shielded from the transmitter and
only received the CW signal when it reflected off an airplane.
Detecting the audio-frequency Doppler shift in the return seems
unlikely for biplane speeds and spark-gap bandwidth and it goes away
as the plane approaches.

In "The Wizard War" Dr Jones wrote that early '40's German field radar
transmitters were as stable in frequency as the best British lab
standards, apparently because they could grind quartz crystals better.
He certainly had a lot of respect for German equipment. Then again,
the British chose to use American aircraft radios rather than their
own. As with Russia and Japan their theoretical and lab work was
excellent but they had trouble mass producing it.

Those were the good days...


but the transfer punch/paper roll method beats it every time
particularly
for small parts.

That's a good idea I hadn't seen before.

Ha! You heard it here first!

The traditional center punching tool looks like a funnel with the
center punch sliding in the spout.

Funny, I thought I could not have been *that* original. I went looking for
something like that on the net but could not find it.


These are a gold mine of information;
http://www.amazon.com/Hand-Simple-Tu...s-Practice/dp/
0486264289/ref=sr_1_3?ie=UTF8&s=books&qid=1220099472&sr=1-3
If the link is broken, Google for "Holtzapffel"

Nah, someone else sends me links this way. I just link the first half and
paste in the second line. Got it just fine, thanks.


The yellow one concentrates on turning and should answer your
questions very well, the red one is about hand tools and the history
of screw threads. I don't have the other books yet. They describe
Victorian-era technology in exquisite detail from a master toolmaker's
perspective and often give the inventor of our common tools, for
example Mr. Hale registered the centering square in 1862, Holtzapffel
and Deyerlein began making 3-jaw self-centering lathe chucks in 1811.

Like anything German they are ignored in most English-language history
books although they worked in London since 1787 and helped train
Whitworth. "English and American Tool Builders" gives them only a
paragraph. The Holtzappfel books complement that biographical one by
showing their work.

Solch' is das Leben...

--
Michael Koblic,
Campbell River, BC

On 2008-08-31, Michael Koblic wrote:

----- Original Message -----
From: "DoN. Nichols"
Newsgroups: rec.crafts.metalworking
Sent: Saturday, August 30, 2008 1:47 PM
Subject: Red-neck lathe v2.0


O.K. The v-groove in the vise (likely not a very deep one, but
something to help) is a start. Ideal depth of V-groove would be such
that the two sides of the 'V' are tangent to the diameter of the thing
being held. If it is shallow enough so the tops of the V touch the
circumference of the workpiece it will cut grooves into the workpiece
and will not be as good a grip. Of course, some vises (e.g. toolmakers
vises) have deeper grooves than others do.

So far so good, but I have also a couple of bigger v-blocks if need be.

Good.

[ ... ]

For that you need a wiggler?

Well ... actually a "wiggler" is an indicator used for moving
centers of the workpiece over/under the axis of the lathe, mill, or
drill press spindles.

That was supposed to be a joke...

O.K. No smiley, so I wasn't sure.

Good -- pictures do help a lot. You know -- there are
downloadable PDF files of various old books (out of copyright) which are
very good things to have for what you are trying to do -- or for anyone
with an old manual lathe, mill, and other such tools.

I am beginning to find them. It seems tricky. You do the search one way and
nothing happens, you do it another and out they pop..

Try to find "Modern Machine Shop Practice" (I forget whether
that last word should have an 's' on the end. :-) Don't confuse it with
"Machine Shop Practice" by Moultrecht which is a two-volume set. It is
a good book set to have, but you won't find it for free.

[ ... ]

O.K. Yes, that would want to run fairly fast. 2000 RPM would
be only slightly over 65 SFM (Surface Feet per Minute -- the measure
used for determining the speed of the workpiece/tool interface. (take
the diameter in inches, multiply by Pi, divide by 12 to give the
circumference in feet, and divide that into the RPM. That is a fairly
conservative speed for HSS (High Speed Steel) in brass.

I run most of my drills slower than the book speed. I have not find a
convincing argument that it is harmful to the tools.

It typically puts more stress on the flutes of bits.

The centre drills seem
to be an exception - they snap at lower speeds.

Hmm ... check your drill press. Put a round tip piece of stock
in the drill chuck, put a flat piece of metal on the table, and bring
the round end of the rod down on the piece of metal. Look carefully at
the point of contact as you apply pressure. A lot of relatively
inexpensive drill presses flex -- both the arm supporting the table and
the head. This results in the contact point skidding towards you. This
applies lateral force to the point -- and with the skinny point of a
1/8" center drill and it *will* break. A higher speed means that you
are less likely to apply as much force to the spindle feed levers.

I swear the first one snapped just by me looking at it...

It feels like that sometimes. Were you using it in a drill
press, or in a hand drill? The drill press is the better bet. And
don't just keep pushing it in -- go a little way in, then back the
spindle up to let chips clear, then in again, etc. Normally you don't
need cutting fluids on a free-machining brass, but I don't know what the
characteristics of the cast brass which you are working with might be.
I wonder whether it could be a bronze? Not likely, as those are more
expensive, but they are tougher alloys.

Garage sale candlesticks - generic brass all the way. Very soft.

Very soft can be a problem -- it gums up the flutes of the bit.
360L brass has lead in it and is a bit harder than normal brass, but the
lead lubricates the cuts, so it is a very nice machining material. Cast
brass is more likely to be too soft to machine well.


I just took apart a very old Sears cordless drill and liberated a 12V
motor
as well as a 3/8" chuck and a whole bunch of cool little gears. Also I
found
an old 12V motor with some strange reduction gear which, many years ago
was
going to be a pottery wheel for kids. Some of this stuff has got to be
useful even though 12V is not exactly ideal.

An old automobile battery and a battery charger to keep it near
full charge and you should be fine. And that would be a lot cheaper
than a lab power supply of sufficient capacity to handle your tools.
(Hmm ... if it is small enough, perhaps a motorcycle battery would be
sufficient.

I have a couple of power supplies - one should give steady 5 amps which as
it turns out may not be enough. The other one should give 20 amps. I have
not tried that one yet.

But with an automotive battery, it would keep the battery
charged, and the battery would handle the current to start the motor.
(Of course, it really needs to be something like 14.4V to fully charge
the battery.

Note to self: Do not take motors apart without securing the brushes first! A
good way to avoid doing anything productive for an hour...

:-)

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 ---

"DoN. Nichols" wrote in message
...
Try to find "Modern Machine Shop Practice" (I forget whether
that last word should have an 's' on the end. :-) Don't confuse it with
"Machine Shop Practice" by Moultrecht which is a two-volume set. It is
a good book set to have, but you won't find it for free.

Who is the author?


Hmm ... check your drill press. Put a round tip piece of stock
in the drill chuck, put a flat piece of metal on the table, and bring
the round end of the rod down on the piece of metal. Look carefully at
the point of contact as you apply pressure. A lot of relatively
inexpensive drill presses flex -- both the arm supporting the table and
the head. This results in the contact point skidding towards you. This
applies lateral force to the point -- and with the skinny point of a
1/8" center drill and it *will* break. A higher speed means that you
are less likely to apply as much force to the spindle feed levers.

I did not know that test. Will do.

Very soft can be a problem -- it gums up the flutes of the bit.
360L brass has lead in it and is a bit harder than normal brass, but the
lead lubricates the cuts, so it is a very nice machining material. Cast
brass is more likely to be too soft to machine well.

But its overwhelming redeeming quality is that it is cheap.

I have a couple of power supplies - one should give steady 5 amps which
as
it turns out may not be enough. The other one should give 20 amps. I have
not tried that one yet.

But with an automotive battery, it would keep the battery
charged, and the battery would handle the current to start the motor.
(Of course, it really needs to be something like 14.4V to fully charge
the battery.

13.7 V both of them. And a charger somewhere in the garage. In the end this
is the way I may have to go: The first PS shuts down at start-up. I haven't
worked out if it is the normal protection kicking itn at 7 Amps or a fault.
I am measuring the current with a clamp meter and it does not even get up to
1 Amp. However, the protection is probably faster than the meter response...

Anyway, that part has been put off for the moment: Today was the day to try
applying a green patina to brass and soldering a brass ball to a candlestick
cup.
It is so easy to get distracted by things that are not immediately relevant
but fun to play with...

--
Michael Koblic,
Campbell River, BC

On 2008-09-01, Michael Koblic wrote:

"DoN. Nichols" wrote in message
...
Try to find "Modern Machine Shop Practice" (I forget whether
that last word should have an 's' on the end. :-) Don't confuse it with
"Machine Shop Practice" by Moultrecht which is a two-volume set. It is
a good book set to have, but you won't find it for free.

Who is the author?

Johshua Rose.

A Google search on just the book title found this as the first hit:

http://digital.lib.msu.edu/collections/index.cfm?TitleID=274

The publication date was: 1887-88

I know that there is a scanned and re-typeset version of it out
there somewhere, because I have a copy here. It was at some
university's project IIRC. "Project Gutenberg" Nope -- not there, it
must have been some other scanning project. But I do know that the book
is out there somewhere -- unless it has been shut down by the "copyright
police".

Hmm ... check your drill press. Put a round tip piece of stock
in the drill chuck, put a flat piece of metal on the table, and bring
the round end of the rod down on the piece of metal. Look carefully at
the point of contact as you apply pressure. A lot of relatively
inexpensive drill presses flex -- both the arm supporting the table and
the head. This results in the contact point skidding towards you. This
applies lateral force to the point -- and with the skinny point of a
1/8" center drill and it *will* break. A higher speed means that you
are less likely to apply as much force to the spindle feed levers.

I did not know that test. Will do.

I've never heard of the test before. But I tried to come up
with something which would demonstrate the problem if you have it.

Very soft can be a problem -- it gums up the flutes of the bit.
360L brass has lead in it and is a bit harder than normal brass, but the
lead lubricates the cuts, so it is a very nice machining material. Cast
brass is more likely to be too soft to machine well.

But its overwhelming redeeming quality is that it is cheap.

Hmm ... depending on how much you need, you might look at the
price for a 6' length of 360 brass 3/4" diameter. I get it from MSC
from time to time. Last time I bought that it cost me $29.02 per bar,
and I bought three of them for future needs. Hmm ... that was back in
2003, so it certainly will cost more now. But still, compare that with
the cost of enough of those candlesticks to make up six feet -- and this
is a free machining brass.

I have a couple of power supplies - one should give steady 5 amps which
as
it turns out may not be enough. The other one should give 20 amps. I have
not tried that one yet.

But with an automotive battery, it would keep the battery
charged, and the battery would handle the current to start the motor.
(Of course, it really needs to be something like 14.4V to fully charge
the battery.

13.7 V both of them.

A bit low to reach a full charge in a lead-acid battery, though
close to what a fully charged one will measure with no charging current
and no load.

And a charger somewhere in the garage. In the end this
is the way I may have to go: The first PS shuts down at start-up. I haven't
worked out if it is the normal protection kicking itn at 7 Amps or a fault.

The starting current will be a lot higher than the current to
keep it running. Hmm ... can you hook a large electrolytic capacitor
across the supply to take that first surge? Something like 2000 to
10000 uF?

I am measuring the current with a clamp meter and it does not even get up to
1 Amp. However, the protection is probably faster than the meter response...

Which clamp-on meter? Many of them will only measure AC
currents, not DC.

Anyway, that part has been put off for the moment: Today was the day to try
applying a green patina to brass and soldering a brass ball to a candlestick
cup.

Hmm ... back when he was still around, "Teenut" would answer the
question of how to get a patina on brass by saying "Cat pee!". In
particular, bury it in the cat's litter box for a few days.

It is so easy to get distracted by things that are not immediately relevant
but fun to play with...

Why do you think that we are all here?

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 ---

----- Original Message -----
From: "DoN. Nichols"
Newsgroups: rec.crafts.metalworking
Sent: Sunday, August 31, 2008 7:07 PM
Subject: Red-neck lathe v2.0


Johshua Rose.

A Google search on just the book title found this as the first hit:

http://digital.lib.msu.edu/collections/index.cfm?TitleID=274

I will put it on the list. I have just printed out over 100 pages on "How to
use a lathe". That should keep me going for a day or two.

Hmm ... depending on how much you need, you might look at the
price for a 6' length of 360 brass 3/4" diameter. I get it from MSC
from time to time. Last time I bought that it cost me $29.02 per bar,
and I bought three of them for future needs. Hmm ... that was back in
2003, so it certainly will cost more now. But still, compare that with
the cost of enough of those candlesticks to make up six feet -- and this
is a free machining brass.

At about 25 cents a candle stick it is hard to beat.


The starting current will be a lot higher than the current to
keep it running. Hmm ... can you hook a large electrolytic capacitor
across the supply to take that first surge? Something like 2000 to
10000 uF?

I think it has one already. They are pretty standard on these regulated
supplies. I shall look into it in a few days in more detail.

I am measuring the current with a clamp meter and it does not even get up
to
1 Amp. However, the protection is probably faster than the meter
response...

Which clamp-on meter? Many of them will only measure AC
currents, not DC.

This one does. Sears 82369.


Hmm ... back when he was still around, "Teenut" would answer the
question of how to get a patina on brass by saying "Cat pee!". In
particular, bury it in the cat's litter box for a few days.

Ah, but was it green, blue, red, brown or black? My guess is green is
probably right as I am doing nearly the same. Without the cat. Today I was
trying two different methods. I shall know tomorrow which one works better.

I used to be able to do blue but I have not tried for some time.

Michael Koblic,
Campbell River, BC

On Sep 1, 1:23*am, "Michael Koblic" wrote:
----- Original Message -----
From: "DoN. Nichols"
....
Which clamp-on meter? *Many of them will only measure AC
currents, not DC.
This one does. Sears 82369.
Michael Koblic,

I took a serious look at one of those, bought it and tried it on a
lightbulb wire on my car in the parking lot. The reading was unstable
because the zero drifted too quickly. I returned it.

On 2008-09-01, Michael Koblic wrote:

----- Original Message -----
From: "DoN. Nichols"
Newsgroups: rec.crafts.metalworking
Sent: Sunday, August 31, 2008 7:07 PM
Subject: Red-neck lathe v2.0


Johshua Rose.

A Google search on just the book title found this as the first hit:

http://digital.lib.msu.edu/collections/index.cfm?TitleID=274

I will put it on the list. I have just printed out over 100 pages on "How to
use a lathe". That should keep me going for a day or two.

O.K. That is a good start. Which one -- the South Bend or the
Atlas version? Each is somewhat focused on its own lathes, but most of
what they say is truly general.

Hmm ... depending on how much you need, you might look at the
price for a 6' length of 360 brass 3/4" diameter. I get it from MSC
from time to time. Last time I bought that it cost me $29.02 per bar,
and I bought three of them for future needs. Hmm ... that was back in
2003, so it certainly will cost more now. But still, compare that with
the cost of enough of those candlesticks to make up six feet -- and this
is a free machining brass.

At about 25 cents a candle stick it is hard to beat.

O.K. How many vs how many you actually need? What about when
you need more? If you try some 360 brass you will find it really nice
to work.

The starting current will be a lot higher than the current to
keep it running. Hmm ... can you hook a large electrolytic capacitor
across the supply to take that first surge? Something like 2000 to
10000 uF?

I think it has one already. They are pretty standard on these regulated
supplies. I shall look into it in a few days in more detail.

Those with current limiting usually have the capacitor before
the current sense, so it will be shut down by the starting spike. One
connected to the external terminals will help a log for starting surges.

I am measuring the current with a clamp meter and it does not even get up
to
1 Amp. However, the protection is probably faster than the meter
response...

Which clamp-on meter? Many of them will only measure AC
currents, not DC.

This one does. Sears 82369.

O.K.

Hmm ... back when he was still around, "Teenut" would answer the
question of how to get a patina on brass by saying "Cat pee!". In
particular, bury it in the cat's litter box for a few days.

Ah, but was it green, blue, red, brown or black?

Green, IIRC.

My guess is green is
probably right as I am doing nearly the same. Without the cat. Today I was
trying two different methods. I shall know tomorrow which one works better.

O.K.

I used to be able to do blue but I have not tried for some time.

It will be interesting to hear what the results of the various
methods are.

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 ---

"Jim Wilkins" wrote in message
...
On Sep 1, 1:23 am, "Michael Koblic" wrote:
----- Original Message -----
From: "DoN. Nichols"
....
Which clamp-on meter? Many of them will only measure AC
currents, not DC.
This one does. Sears 82369.
Michael Koblic,

I took a serious look at one of those, bought it and tried it on a
lightbulb wire on my car in the parking lot. The reading was unstable
because the zero drifted too quickly. I returned it.

***I bought mine on EBay for a very low sum so I am more tolerant. However,
having said that, I was quite impressed with it. I tested it across various
ranges using fixed resistors and one of my power supplies. I tried to
multiply the readings by coiling the lead and it showed the multiples just
fine. Yes, you have to zero it before you start measuring. However, for
measuring high currents it is better than almost anything else I have had
before which had to be connected into a broken circuit. The internal
resistances usually played havoc with the voltage, however small they were.

There are quite a few more expensive ones but for someone who is happy with
the current reading within 10% this one works for me. I bought it initially
with a view to do some electroplating and found it useful incidentally when
part of the house heating died.
YMMV :-)

--
Michael Koblic,
Campbell River, BC

"DoN. Nichols" wrote in message
...

O.K. That is a good start. Which one -- the South Bend or the
Atlas version? Each is somewhat focused on its own lathes, but most of
what they say is truly general.

Birmingham (?)

At about 25 cents a candle stick it is hard to beat.

O.K. How many vs how many you actually need? What about when
you need more? If you try some 360 brass you will find it really nice
to work.

I am sure you are right. However, with me it works almost the other way
round: When I see something I ask myslef "Could it be useful?" and if the
answer is yes, I offer the distressed widow a quarter to take that junk
away...

I will not be going to heaven.

The starting current will be a lot higher than the current to
keep it running. Hmm ... can you hook a large electrolytic capacitor
across the supply to take that first surge? Something like 2000 to
10000 uF?

I think it has one already. They are pretty standard on these regulated
supplies. I shall look into it in a few days in more detail.

Those with current limiting usually have the capacitor before
the current sense, so it will be shut down by the starting spike. One
connected to the external terminals will help a log for starting surges.

Right. I need to establish first if there is a surge. A 2.5 ohm resistor
should tell me. If it shuts down with that I have other problems.

Green, IIRC.

My guess is green is
probably right as I am doing nearly the same. Without the cat. Today I
was
trying two different methods. I shall know tomorrow which one works
better.

O.K.

I used to be able to do blue but I have not tried for some time.

It will be interesting to hear what the results of the various
methods are.

Well, both sucked. Leaving it out in the open and respraying it produced a
sort of spotty ugly rash. The big surprise was the "smothered" piece - not a
tiny spot of anything! I cranked up the strength of the cat's pee and am
repeating it just now with both pieces left out - they are two different
kinds of brass. The one that refused to take any patina I *know* did so 10
years ago - but then it was blue patina:

http://www.flickr.com/photos/2768312...7605638700703/

This is the green one I only did once:

http://www.flickr.com/photos/2768312...7605638700703/

I was sloppy in those days, did not keep records and for the love of me
cannot remember how I did it.

I must photograph the various bits I am doing now. I do not think I am
describing them very well.

--
Michael Koblic,
Campbell River, BC

"DoN. Nichols" wrote in message
...

snip

OK, see if you can view these:

http://www.flickr.com/photos/2768312...7607066256337/


--
Michael Koblic,
Campbell River, BC