I've been making some parts out of 1/2" aluminum rod which get turned down
to 0.200 for 3/8" of an inch, and the end chopped off.

they need to look pretty and the fillet has to not be gouged out.

What I've been doing is

throw a 1 foot rod in the sherline lathe, support the other end with a
steady rest with brass feet and lots of oil.

in 0.025 passes neck the rod down to almost 0.200. Deepr cuts seem to
cause the rod chatter and "walk" around working the steady rest loose.

move back over to the 1/2 side and face off the wavy shoulder off in a few
passes.

an uninterrupted finishing pass along the 0.200 side then out along the
faced off side

turn the rod OD to exactly 0.500

face off the 0.200 side so it's exactly 0.375 long

cut the part off with a parting blade, final length is about 7/8ths

slide steady rest towards chuck and repeat.

Is this what anybody else would do? I have no machinist pals to drop by
and chat about stuff like this with.

Cydrome Leader fired this volley in news:kiq0ns
:


slide steady rest towards chuck and repeat.

From this, can we assume that the spindle bore in the Sherline is too
small to pass the 1/2" material through?

If the bore is large enough, you'd be better off setting up a feed stop
you can swing out of the way when machining, and only have as much
overhang from the chuck as necessary to turn and part the work. Then
loosen the chuck, feed more out to the stop, and re-tighten.

If you didn't want to build a feed stop, you could still make a small
gauge that would allow you to measure the stickout from the chuck -- or
you could just eyeball it, if that's what you're doing now.

LLoyd


Lloyd

On Mar 25, 10:15*am, Cydrome Leader wrote:
I've been making some parts out of 1/2" aluminum rod which get turned down
to 0.200 for 3/8" of an inch, and the end chopped off.

they need to look pretty and the fillet has to not be gouged out.

What I've been doing is

throw a 1 foot rod in the sherline lathe, support the other end with a
steady rest with brass feet and lots of oil.

in 0.025 passes neck the rod down to almost 0.200. Deepr cuts seem to
cause the rod chatter and "walk" around working the steady rest loose.

move back over to the 1/2 side and face off the wavy shoulder off in a few
passes.

an uninterrupted finishing pass along the 0.200 side then out along the
faced off side

turn the rod OD to exactly 0.500

face off the 0.200 side so it's exactly 0.375 long

cut the part off with a parting blade, final length is about 7/8ths

slide steady rest towards chuck and repeat.

Is this what anybody else would do? I have no machinist pals to drop by
and chat about stuff like this with.

Do you have Adult Education for machining in your area? Do they have
night classes?

Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Cydrome Leader fired this volley in news:kiq0ns
:


slide steady rest towards chuck and repeat.

From this, can we assume that the spindle bore in the Sherline is too
small to pass the 1/2" material through?

the spindle bore is too small. It's something like 3/8".

If the bore is large enough, you'd be better off setting up a feed stop
you can swing out of the way when machining, and only have as much
overhang from the chuck as necessary to turn and part the work. Then
loosen the chuck, feed more out to the stop, and re-tighten.

Is there a sensible way to make a carriage stop for a sherline? It's
pretty easy to overshoot a cut and you can't undo that. Since mine
is fed by hand, I guess I'd feel the carriage slamming into metal block or
something clamped on the ways, but it just doesn't seem like it would be
all that accurate.

If you didn't want to build a feed stop, you could still make a small
gauge that would allow you to measure the stickout from the chuck -- or
you could just eyeball it, if that's what you're doing now.

Assuming the rod would fit though the spindle, I'd probably use the
toolpost as a depth stop of sorts. For right now, I'm just working towards
the chuck. I've been touching the cutting tool to the end of the rod with
a piece of aluminum foil as a feeler, resetting the DRO to 0 and working
from there. Since the the side that gets faced off has to be cut again and
again by eye until it's smooth, that then becomes 0 again and I face the
0.200" diameter part off at exactly 0.375". Changing the reference point
for measurements seem wrong to me, but I can't think of a better way to do
this.

Is the rest of the process I'm using sensible though?

Instead of doing a lot of cuts with a long rod, I'd start by making about-the-right-length
cylinders (maybe just with a hacksaw), and holding them in a collet
or (even better) soft jaws in a 3-jaw chuck. Finish one end square, so that
when you reverse it in the soft jaws, the soft jaws can act as the stop for a
second operation that makes the 3/8" nub and cuts to length.

The result would be a batch of parts, going from a rod, to rough cylinders,
to one-end-flat cylinders, to one-end-flat/one-end-stepped finished
length parts.

jon_banquer wrote:
On Mar 25, 10:15?am, Cydrome Leader wrote:
I've been making some parts out of 1/2" aluminum rod which get turned down
to 0.200 for 3/8" of an inch, and the end chopped off.

they need to look pretty and the fillet has to not be gouged out.

What I've been doing is

throw a 1 foot rod in the sherline lathe, support the other end with a
steady rest with brass feet and lots of oil.

in 0.025 passes neck the rod down to almost 0.200. Deepr cuts seem to
cause the rod chatter and "walk" around working the steady rest loose.

move back over to the 1/2 side and face off the wavy shoulder off in a few
passes.

an uninterrupted finishing pass along the 0.200 side then out along the
faced off side

turn the rod OD to exactly 0.500

face off the 0.200 side so it's exactly 0.375 long

cut the part off with a parting blade, final length is about 7/8ths

slide steady rest towards chuck and repeat.

Is this what anybody else would do? I have no machinist pals to drop by
and chat about stuff like this with.

Do you have Adult Education for machining in your area? Do they have
night classes?

I've not found any. Nobody seems interested in teaching any skills that
involve using your hands these days. It's pretty sad.

whit3rd wrote:
Instead of doing a lot of cuts with a long rod, I'd start by making about-the-right-length
cylinders (maybe just with a hacksaw), and holding them in a collet
or (even better) soft jaws in a 3-jaw chuck. Finish one end square, so that
when you reverse it in the soft jaws, the soft jaws can act as the stop for a
second operation that makes the 3/8" nub and cuts to length.

I though about chopping the parts up first, but there's no way to grab
them. The 0.500" side of things will be less than 1/8" deep- not enough to
securely clamp in the chuck and turn the other end down with. If I leave
the rough end of the rod longer, I end up with about 50% scrap cut offs.

The result would be a batch of parts, going from a rod, to rough cylinders,
to one-end-flat cylinders, to one-end-flat/one-end-stepped finished
length parts.

If I had or got a 1/2" collet, what would be the maximum "overhang" ratio
for clamped to unclamped material?

How would you cut the stepped part, by hand if you had to?

"Cydrome Leader" wrote in message
...
I've been making some parts out of 1/2" aluminum rod which get
turned down
to 0.200 for 3/8" of an inch, and the end chopped off.
...

Is this what anybody else would do? I have no machinist pals to drop
by
and chat about stuff like this with.

If I read you right they are shaped like a thick-brimmed top hat or a
rimmed bushing.
http://image.made-in-china.com/2f0j0...te-Bushing.jpg

I'd do about the same as you except that I rough nearly to size, then
make one or two finish cuts based on measuring the part and advancing
the bit almost half the oversize. This compensates for the wear in my
1965 lathe. If I'm careful I can hit the diameter within 0.0002", over
a short length that varies with shaft deflection.

For the shoulder position, if I didn't have a micrometer carriage stop
I'd face it square and a little long after finishing the diameter,
then locate the facing bit 0.375" from the shoulder with dial calipers
or some handy gauge and face off the end of the 0.200 diameter. I can
usually get within 0.005" with a ruler and magnifier headband.

I locate the cutoff bit from the shoulder with the depth rod end of a
dial caliper. The 4" size is handier for confined spaces, especially
when milling. Rocking the caliper slightly shows whether it is
contacting the shoulder or the cutoff bit. It's probably good to
0.001" but I may cut it long and face smoothly to length with the part
reversed in the chuck.

I had a company-property Sherline lathe and mill to play with for a
while. After using a bigger lathe it seems incredibly limiting. My 10"
lathe will do the same tiny work like threading custom #0-80 screws. I
kept my first small lathe after buying it because the small one spins
much faster and so is better for drilling small deep holes, and
polishing.

I grind my HSS bits about like this:
http://www.iowa-industrial.com/Trist...image-No-2.jpg
but with a more acute angle at the tip so they both turn and face
cleanly. The shank has to be angled in the tool post, easy with a
Multifix or old-style lantern toolpost, harder with a square or
turret. If the junction of the diameter and face matter I grind the
point sharp or rounded to match, or use a triangular insert.
jsw

Cydrome Leader fired this volley in news:kiqamj
:

Is the rest of the process I'm using sensible though?

It works; it's not the best.

If you can afford to waste a little stock, you'll get better work by
parting it up into lengths you can manage in the chuck, and working with
little overhang.

If you can't pass it through the headstock, then cut it into lengths long
enough to make two pieces (plus the amount to part them and finish off
the 'cap' part).

Chuck, turn on end to the .2" dimension. Then flip it around and cut the
other end to .2". Finally, part, finish one, re-chuck the other and
finish it.

Even though it's more steps, you'll get better finishes with less
chatter.

LLoyd

Cydrome Leader fired this volley in
:

I though about chopping the parts up first, but there's no way to grab
them. The 0.500" side of things will be less than 1/8" deep- not
enough to securely clamp in the chuck and turn the other end down
with. If I leave the rough end of t

See my post about cutting them into "two-part lengths".

Lloyd

On Monday, March 25, 2013 2:17:27 PM UTC-7, Cydrome Leader wrote:
whit3rd wrote:

Instead of doing a lot of cuts with a long rod, I'd start by making about-the-right-length

cylinders (maybe just with a hacksaw), and holding them in a collet

or (even better) soft jaws in a 3-jaw chuck.

If I had or got a 1/2" collet, what would be the maximum "overhang" ratio
for clamped to unclamped material?

Less than one would think; holding a tack by the head while cutting
to make the pointy part... would work. Soft jaws in 3-jaw chuck is best.
Hard collets, not so grabby (but you can get soft collets to
custom-bore for this kind of task).

How would you cut the stepped part, by hand if you had to?

A live center in the tailstock can keep the work bottomed in a chuck
while you do the cut in conventional fashion. Many chucks (and collets)
can be fitted with a stop so the work bottoms at a repeatable depth.

I've actually done this kind of work with a file, chucking half
inch rod in a drill press. Not recommended, but it DID work.

whit3rd fired this volley in
:

Less than one would think; holding a tack by the head while cutting
to make the pointy part... would work. Soft jaws in 3-jaw chuck is
best. Hard collets, not so grabby (but you can get soft collets to
custom-bore for this kind of task).


It's just not necessary! Turn two parts on one piece. You'll have the
..2"o.d. 'stub' to chuck on while turning the second stub.

Like the sign says, "THIMK!"

Lloyd

On Mon, 25 Mar 2013 21:17:27 +0000 (UTC), Cydrome Leader
wrote:

whit3rd wrote:
Instead of doing a lot of cuts with a long rod, I'd start by making about-the-right-length
cylinders (maybe just with a hacksaw), and holding them in a collet
or (even better) soft jaws in a 3-jaw chuck. Finish one end square, so that
when you reverse it in the soft jaws, the soft jaws can act as the stop for a
second operation that makes the 3/8" nub and cuts to length.

I though about chopping the parts up first, but there's no way to grab
them. The 0.500" side of things will be less than 1/8" deep- not enough to
securely clamp in the chuck and turn the other end down with. If I leave
the rough end of the rod longer, I end up with about 50% scrap cut offs.

The result would be a batch of parts, going from a rod, to rough cylinders,
to one-end-flat cylinders, to one-end-flat/one-end-stepped finished
length parts.

If I had or got a 1/2" collet, what would be the maximum "overhang" ratio
for clamped to unclamped material?

That..depends on the quality of the collet and the fit. Ive done
stuff that only had 3/16" in the collet and was 3/4" long...on a
Hardinge DV-59

How would you cut the stepped part, by hand if you had to?

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
whit3rd fired this volley in
:

Less than one would think; holding a tack by the head while cutting
to make the pointy part... would work. Soft jaws in 3-jaw chuck
is
best. Hard collets, not so grabby (but you can get soft collets to
custom-bore for this kind of task).


It's just not necessary! Turn two parts on one piece. You'll have
the
.2"o.d. 'stub' to chuck on while turning the second stub.

Like the sign says, "THIMK!"

Lloyd

An alternative is turning parts on both ends of the full-length stock,
so you have to reset the steady rest half as often.
jsw

"Jim Wilkins" wrote in message
...
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
whit3rd fired this volley in
:

Less than one would think; holding a tack by the head while cutting
to make the pointy part... would work. Soft jaws in 3-jaw chuck is
best. Hard collets, not so grabby (but you can get soft collets to
custom-bore for this kind of task).


It's just not necessary! Turn two parts on one piece. You'll have the
.2"o.d. 'stub' to chuck on while turning the second stub.

Like the sign says, "THIMK!"

Lloyd

An alternative is turning parts on both ends of the full-length stock, so
you have to reset the steady rest half as often.
jsw

Use a follower rest and you won't have to reset it at all.

Lloyd E. Sponenburgh lloydspinsidemindspring.com wrote:
Cydrome Leader fired this volley in news:kiqamj
:

Is the rest of the process I'm using sensible though?

It works; it's not the best.

If you can afford to waste a little stock, you'll get better work by
parting it up into lengths you can manage in the chuck, and working with
little overhang.

If you can't pass it through the headstock, then cut it into lengths long
enough to make two pieces (plus the amount to part them and finish off
the 'cap' part).

Chuck, turn on end to the .2" dimension. Then flip it around and cut the
other end to .2". Finally, part, finish one, re-chuck the other and
finish it.

Even though it's more steps, you'll get better finishes with less
chatter.

LLoyd

Super.

I'll try this. The first parts didn't work anyways for other reasons, so
it's time for try 2.

Jim Wilkins wrote:
"Cydrome Leader" wrote in message
...
I've been making some parts out of 1/2" aluminum rod which get
turned down
to 0.200 for 3/8" of an inch, and the end chopped off.
...

Is this what anybody else would do? I have no machinist pals to drop
by
and chat about stuff like this with.

If I read you right they are shaped like a thick-brimmed top hat or a
rimmed bushing.
http://image.made-in-china.com/2f0j0...te-Bushing.jpg

pretty much, but the top of the hat is much tinner. If a hershey's kiss
had a bone, that's what I'm making.

I'd do about the same as you except that I rough nearly to size, then
make one or two finish cuts based on measuring the part and advancing
the bit almost half the oversize. This compensates for the wear in my
1965 lathe. If I'm careful I can hit the diameter within 0.0002", over
a short length that varies with shaft deflection.

For the shoulder position, if I didn't have a micrometer carriage stop
I'd face it square and a little long after finishing the diameter,
then locate the facing bit 0.375" from the shoulder with dial calipers
or some handy gauge and face off the end of the 0.200 diameter. I can
usually get within 0.005" with a ruler and magnifier headband.

I locate the cutoff bit from the shoulder with the depth rod end of a
dial caliper. The 4" size is handier for confined spaces, especially
when milling. Rocking the caliper slightly shows whether it is
contacting the shoulder or the cutoff bit. It's probably good to
0.001" but I may cut it long and face smoothly to length with the part
reversed in the chuck.

I had a company-property Sherline lathe and mill to play with for a
while. After using a bigger lathe it seems incredibly limiting. My 10"
lathe will do the same tiny work like threading custom #0-80 screws. I
kept my first small lathe after buying it because the small one spins
much faster and so is better for drilling small deep holes, and
polishing.

I grind my HSS bits about like this:
http://www.iowa-industrial.com/Trist...image-No-2.jpg
but with a more acute angle at the tip so they both turn and face
cleanly. The shank has to be angled in the tool post, easy with a
Multifix or old-style lantern toolpost, harder with a square or
turret. If the junction of the diameter and face matter I grind the
point sharp or rounded to match, or use a triangular insert.
jsw

I've been using a HSS cutter (right hand? it cuts the same way as the ones
in your photos) on a tool post angled to the left so there's clearance
when facing from the 0.200 peg to the full OD of the rod.

On Tue, 26 Mar 2013 18:28:19 +0000 (UTC), Cydrome Leader
wrote:


pretty much, but the top of the hat is much tinner. If a hershey's kiss
had a bone, that's what I'm making.


Ah...er...ahum. Neve mind.

Gunner, who had a momentary flash about an erectile disfunction
assistance device for a Hersheys kiss and need to go flush out his
brain...