There's a couple projects I'd like to make, but it's been 30 years
since I've done any serious metalwork (decent HS machine shop). I'd
like to do a little metalwork again, so here's the two projects, can
you tell me which machine I'll need to start out with? Any other good
advice also welcome.

1) Grinder shaft adapter: 3/4" coarse thread to 1/2" reducer/adapter
(I have a bench grinder w/ a 3/4" threaded shaft. I want to reduce
that shaft to a 1/2" shaft)

2) Stickler log splitting type of tool. This is basically a solid
metal cone: about 4-5" at wide diameter down to a sharp point, about
12" long, the whole thing coarse threaded. Threaded hole also in wide
dia. side to accept shaft. When powered, this is used to split logs

A lathe can make both of these, right? Are these really complex
projects? Can a mini lathe do the work? Are the inexpensive harbor
freight units OK?

Thanks,
H

On 06/16/2010 10:45 AM, hylourgos wrote:
There's a couple projects I'd like to make, but it's been 30 years
since I've done any serious metalwork (decent HS machine shop). I'd
like to do a little metalwork again, so here's the two projects, can
you tell me which machine I'll need to start out with? Any other good
advice also welcome.

1) Grinder shaft adapter: 3/4" coarse thread to 1/2" reducer/adapter
(I have a bench grinder w/ a 3/4" threaded shaft. I want to reduce
that shaft to a 1/2" shaft)

2) Stickler log splitting type of tool. This is basically a solid
metal cone: about 4-5" at wide diameter down to a sharp point, about
12" long, the whole thing coarse threaded. Threaded hole also in wide
dia. side to accept shaft. When powered, this is used to split logs

A lathe can make both of these, right?

Yes, although the log splitter will be an interesting challenge in work
holding and threading -- I'm envisioning turning it between centers that
are spherical instead of the usual conical, and wondering how you'll
hold the pointy end. Or perhaps making a taper turning attachment.

Are these really complex projects?

Threading is considered to be advanced machining to some. I like it,
but I still can't do it repeatably without go/no-go gauges or the part
that I'm trying to mate to.

Can a mini lathe do the work?

A mini lathe may have trouble with the log splitter -- that's pretty
big, particularly if it's steel or cast iron. You could probably coax a
bigger mini-lathe to do the job, but it'd be uncomfortable.

Are the inexpensive harbor freight units OK?

After getting an inexpensive import lathe, all I can say is that I wish
I'd been more patient and gotten a good used professional one. But I
think I could do it on my Smithy, so you could probably do it on
something equivalent.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

On 2010-06-16, hylourgos wrote:
There's a couple projects I'd like to make, but it's been 30 years
since I've done any serious metalwork (decent HS machine shop). I'd
like to do a little metalwork again, so here's the two projects, can
you tell me which machine I'll need to start out with? Any other good
advice also welcome.

1) Grinder shaft adapter: 3/4" coarse thread to 1/2" reducer/adapter
(I have a bench grinder w/ a 3/4" threaded shaft. I want to reduce
that shaft to a 1/2" shaft)

O.K. That sounds like a lathe -- with threading gearing for
inch threads.

2) Stickler log splitting type of tool. This is basically a solid
metal cone: about 4-5" at wide diameter down to a sharp point, about
12" long, the whole thing coarse threaded. Threaded hole also in wide
dia. side to accept shaft. When powered, this is used to split logs

Hmm ... a bit trickier.

A lathe can make both of these, right? Are these really complex
projects? Can a mini lathe do the work?

A bit more material to remove than a mini lathe would be happy
with.

and the thread is a bit more of a trick, since it requires both
threading capability (likely a coarser thread than the mini lathes are
likely to handle) and a taper attachment which can be used at the same
time.

Are the inexpensive harbor
freight units OK?

I don't think that they are available with taper attachments, so
I don't think that you can make the splitter with them. And I don't
think that they cut coarse enough thread pitches as well.

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 ---

"hylourgos" wrote in message
...
There's a couple projects I'd like to make, but it's been 30 years
since I've done any serious metalwork (decent HS machine shop). I'd
like to do a little metalwork again, so here's the two projects, can
you tell me which machine I'll need to start out with? Any other good
advice also welcome.

1) Grinder shaft adapter: 3/4" coarse thread to 1/2" reducer/adapter
(I have a bench grinder w/ a 3/4" threaded shaft. I want to reduce
that shaft to a 1/2" shaft)

Are you contemplating turning the 3/4" dia. shaft to 1/2"? If so I think I
would leave the grinder shaft as is and if you needed a smaller grinder just
buy one that is smaller. Cheap HF grinders with good wheels installed work
just fine.

If you are going to make a shaft extender to mound a grinding wheel this may
cause some problems as you will be extending the wheel farther from the
bearing. Probably OK for a buff wheel but not good for grinding due to
vibration problems and I mught be a little worried about a wheel coming
loose on you with such a set up.


2) Stickler log splitting type of tool. This is basically a solid
metal cone: about 4-5" at wide diameter down to a sharp point, about
12" long, the whole thing coarse threaded. Threaded hole also in wide
dia. side to accept shaft. When powered, this is used to split logs

A lathe can make both of these, right? Are these really complex
projects? Can a mini lathe do the work? Are the inexpensive harbor
freight units OK?

Neither a cheap HF lathe or a mini would be really good at this project.
You need a good size lathe with a taper attachment for such a project. I
would think and even with one of those it would be a real tricky setup.
Probably a lot cheaper and easier to get one prefab.

--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.

On Jun 16, 8:18*pm, "Roger Shoaf" wrote:
"hylourgos" wrote in message

...

There's a couple projects I'd like to make, but it's been 30 years
since I've done any serious metalwork (decent HS machine shop). I'd
like to do a little metalwork again, so here's the two projects, can
you tell me which machine I'll need to start out with? Any other good
advice also welcome.

1) Grinder shaft adapter: 3/4" coarse thread to 1/2" reducer/adapter
(I have a bench grinder w/ a 3/4" threaded shaft. I want to reduce
that shaft to a 1/2" shaft)

Are you contemplating turning the 3/4" dia. shaft to 1/2"? *If so I think I
would leave the grinder shaft as is and if you needed a smaller grinder just
buy one that is smaller. *Cheap HF grinders with good wheels installed work
just fine.

If you are going to make a shaft extender to mound a grinding wheel this may
cause some problems as you will be extending the wheel farther from the
bearing. *Probably OK for a buff wheel but not good for grinding due to
vibration problems and I mught be a little worried about a wheel coming
loose on you with such a set up.



2) Stickler log splitting type of tool. This is basically a solid
metal cone: about 4-5" at wide diameter down to a sharp point, about
12" long, the whole thing coarse threaded. Threaded hole also in wide
dia. side to accept shaft. When powered, this is used to split logs

A lathe can make both of these, right? Are these really complex
projects? Can a mini lathe do the work? Are the inexpensive harbor
freight units OK?

Neither a cheap HF lathe or a mini would be really good at this project.
You need a good size lathe with a taper attachment for such a project. I
would think and even with one of those it would be a real tricky setup.
Probably a lot cheaper and easier to get one prefab.
Roger Shoaf

The splitter wouldn't be too hard to make by offsetting the tailstock,
assuming it moves far enough or you can cobble up something. I made a
tapered mandrel to wind conical wire wood stove handles that way. This
job doesn't require a precision thread form or pitch, on my mandrel
it's just a semicircular groove cut at 4 threads per inch. When you
cut a thread this way the pitch will be wrong because it should be
measured straight down the central axis and the lathe lays it out
along the conical surface instead.

Roughing a 4-5" cylinder of steel down to a cone in any finite length
of time will take a reasonably powerful and rigid lathe. I'm not
familiar with the smaller imports but it would be a workout for my old
10" South Bend which is about equivalent to this in capacity:
http://www.grizzly.com/products/10-x...al-Lathe/G0602
And this in features:
http://www.grizzly.com/products/12-x...ed-Lathe/G9249

The spindle adapter shouldn't be too bad except for threading a blind
hole internally. That will go easier if the lathe has back gears or at
least a low speed around 60 RPM or less. You will want to cut both
threads without loosening the chuck jaws, which could make fitting the
thread snugly to the 3/4" shaft difficult. If you finish the thread
with a bottoming tap the adapter may not run true.

Personally I'd follow Roger's advice and get the right wheel.

These two jobs define a pretty reasonable hobby lathe, but not a cheap
one.

jsw

On Wed, 16 Jun 2010 10:45:10 -0700 (PDT), hylourgos
wrote:

There's a couple projects I'd like to make, but it's been 30 years
since I've done any serious metalwork (decent HS machine shop). I'd
like to do a little metalwork again, so here's the two projects, can
you tell me which machine I'll need to start out with? Any other good
advice also welcome.

1) Grinder shaft adapter: 3/4" coarse thread to 1/2" reducer/adapter
(I have a bench grinder w/ a 3/4" threaded shaft. I want to reduce
that shaft to a 1/2" shaft)

2) Stickler log splitting type of tool. This is basically a solid
metal cone: about 4-5" at wide diameter down to a sharp point, about
12" long, the whole thing coarse threaded. Threaded hole also in wide
dia. side to accept shaft. When powered, this is used to split logs

A lathe can make both of these, right? Are these really complex
projects? Can a mini lathe do the work? Are the inexpensive harbor
freight units OK?

Thanks,
H


Yes a lathe. And no..a mini lathe wont be turning a metal cone 4-5" in
diameter down to a point.

Lots of good surplus lathes out there. Id try to find a decent Logan 11"
lathe if I were you.

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

DoN. Nichols wrote:
On 2010-06-16, hylourgos wrote:
There's a couple projects I'd like to make, but it's been 30 years
since I've done any serious metalwork (decent HS machine shop). I'd
like to do a little metalwork again, so here's the two projects, can
you tell me which machine I'll need to start out with? Any other good
advice also welcome.

1) Grinder shaft adapter: 3/4" coarse thread to 1/2" reducer/adapter
(I have a bench grinder w/ a 3/4" threaded shaft. I want to reduce
that shaft to a 1/2" shaft)

If you just need to reduce it, and not thread it, let the motor be it's
own lathe. You just need to mount it securely, then fashion a cutter
mount that is rigid and can move parallel to the shaft with some
accuracy. You should be able to cobble something together from scrap on
hand.

"Jim Wilkins" wrote in message
...
On Jun 16, 8:18 pm, "Roger Shoaf" wrote:

The splitter wouldn't be too hard to make by offsetting the tailstock,
assuming it moves far enough or you can cobble up something.

Asuming you could offset the center 2-21/2 inches, and mount a 12 inch long
steel bar between them, you would only be able to get to about a 1" diameter
on the small end before you had to stop cutting the taper between centers as
you would have no more center on the tail stock side.

This would mead that you would then have to truncate the cone and make the
tip seperatly and then attach it.

Making the cone tip would not be too dificult until you consider the
threading. To thread, you need to use the carriage rather than the cross
slide which is going to mean a taper attachment or a CNC, and this is going
to get real dicey near the tip.

Now consider the fat end of the cone. You need to face, drill and thread
this end. Whne do you do this? The only way I can thingk to do it would be
to do it first and then screw in something like a trailer hitch ball and
then fabricate some sort center with a concave tip to accept the ball. This
would also require some sort of clever dogging pin to spin the cone on the
lathe.

In total it would take a whole lot of time to make all of the tooling, and
then you are going to need a whole lot of skill and a really good tool to be
able to do this.

Not sure how much one of these things cost to by one from a manufacturer but
it has to be a whole lot cheaper than trung to make one by turning cranks on
a lathe.

I am wondering how a blacksmith might approach making one of these. Those
guys can be really clever and they might be able to forge some sort of auger
to split firewood

Another way would be to invesment cast it. It would probabily be much easier
to deal with wax or foam to get the shape you wanted, but then it would
still be more costly than buying one off the shelf

--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.

On Jun 17, 5:07*pm, "Roger Shoaf" wrote:
"Jim Wilkins" wrote in message
On Jun 16, 8:18 pm, "Roger Shoaf" wrote:

The splitter wouldn't be too hard to make by offsetting the tailstock,
assuming it moves far enough or you can cobble up something.

Asuming you could offset the center 2-21/2 inches, and mount a 12 inch long
steel bar between them, you would only be able to get to about a 1" diameter
on the small end before you had to stop cutting the taper between centers as
you would have no more center on the tail stock side.

This would mead that you would then have to truncate the cone and make the
tip seperatly and then attach it.

Making the cone tip would not be too dificult until you consider the
threading. To thread, you need to use the carriage rather than the cross
slide which is going to mean a taper attachment or a CNC, and this is going
to get real dicey near the tip.

Now consider the fat end of the cone. You need to face, drill and thread
this end. Whne do you do this? The only way I can thingk to do it would be
to do it first and then screw in something like a trailer hitch ball and
then fabricate some sort center with a concave tip to accept the ball. This
would also require some sort of clever dogging pin to spin the cone on the
lathe......
Roger Shoaf

I don't follow your objections.
Why would there be no more center on the tailstock side when the small
end diameter is at 1"?

My wood stove handle winding mandrel tapers to 1/4" to form the ring
that goes around the mounting screw on the stove. I could have cut it
smaller, maybe down to 1/8", by using a half center:
http://www.industrydepot.com/DorianDeadCenters.htm
Scroll down to the "half moon" dead centers.

The nut sorting gauge here was turned between centers to 1/4" OD at
the ends and then threaded starting at the tailstock center:
http://picasaweb.google.com/KB1DAL/T...65927027495682
There was nothing dicey about it, just normal threading to a shoulder.
I've cut an 0-80 thread on a shaft that was supported by the tailstock
center.

When the work is angled by offsetting the tailstock, the tool bit side
will be cut parallel to the ways. You thread it the same way you
thread a cylinder. The tool bit alignment is a little different but
the operation isn't.

I don't think you need to thread all the way to a pointed tip. I might
grind a spade drill bit form on the end and press the log against it
to drill a pilot hole. A half-round gouge-chisel shape that tapers to
a point also makes an effective wood drill. The reamer blade on a
Swiss army knife is a good example.

If you want you could chuck the big end and file the point sharp, then
cut the threads with a triangular file the same way you fix the
mangled lead screw on an old wood augur bit, hold a constant angle and
let the existing thread groove guide the file as you rock it over the
work to trace out the next segment. Once you have the starting groove
you could run the lathe slowly. This is how threading used to be done
and it isn't really all that difficult.

WARNING: File left-handed on a lathe to keep your arms away from the
chuck.

On the big end I'd drill and tap whatever thread it mounts on in use,
then make a plug with a standard 60 degree recess for the headstock
center. It definitely doesn't have to be a ball and socket joint, the
traditional 60 degree point and hole work fine at an angle if kept
greased. This is a good use for a beat-up center from the second-hand
store, or an Enco cheapie, or even a home-made one held in a collet.

You can use a collet and a faceplate at the same time if the spindle
adapter clears. Unscrew the faceplate to pop the adapter loose. This
is why I like old lathes with threaded spindles, they are so adaptable
to odd setups.

The driver is simply an offset tapped hole for some bolt that will
ride in a slot in the faceplate. Yes it slides back and forth in the
slot, but cast iron is forgiving and you can discard the bolt
afterwards.

If this splitter is for a car axle you could torch out the lug hole
section of an old wheel and weld it to the cone. Then you need only a
small center hole in the cone and a drive bolt in one lug hole.

To reduce center wear I would cut away most of the steel in steps
while it's running straight and only finish and thread it at the
angle. When I turned cast iron spheres I made a spreadsheet giving
infeed from the maximum diameter versus distance from the right end
and used it to turn the blanks (dumbbells) down in steps. The
increment between rows was a formula variable so I could rough in
large steps and finish in small ones.

jsw

On Wed, 16 Jun 2010 10:45:10 -0700 (PDT), hylourgos
wrote:

There's a couple projects I'd like to make, but it's been 30 years
since I've done any serious metalwork (decent HS machine shop). I'd
like to do a little metalwork again, so here's the two projects, can
you tell me which machine I'll need to start out with? Any other good
advice also welcome.

1) Grinder shaft adapter: 3/4" coarse thread to 1/2" reducer/adapter
(I have a bench grinder w/ a 3/4" threaded shaft. I want to reduce
that shaft to a 1/2" shaft)

2) Stickler log splitting type of tool. This is basically a solid
metal cone: about 4-5" at wide diameter down to a sharp point, about
12" long, the whole thing coarse threaded. Threaded hole also in wide
dia. side to accept shaft. When powered, this is used to split logs

A lathe can make both of these, right? Are these really complex
projects? Can a mini lathe do the work? Are the inexpensive harbor
freight units OK?

Thanks,
H

The log splitter would be an interesting and challenging project, but
I wouldn't classify it as a "novice" project unless a 9" or bigger
lathe with taper attachment was available.

It isn't a precision thread nor does it need to fit anything, so it
could be made with very primitive methods. Such things were made by
machinists and artificers before there were engine lathes or electric
motors. It just took a while.