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