On Mon, 05 Mar 2012 18:22:27 -0500, Bob S
wrote:

On 5 Mar 2012 05:17:22 GMT, DoN. Nichols wrote:

On 2012-03-05, Bob S wrote:
Thank you for the very comprehensive suggestions!

Comments interspersed below:

Best way to do it. Thanks!

OK, I will do it again :-)


On 4 Mar 2012 06:24:57 GMT, DoN. Nichols wrote:

On 2012-03-04, Bob S wrote:
Background:

I have been messing with camera lenses and was talking about getting a
lathe to make some adapters and maybe learn something and have fun.
(If I just wanted adapters it would be far less expensive to just pay
someone to make them.)

[ ... ]

Hmm ... if you are going to make bayonet mounts (which many
cameras use for their lenses), you will want the milling capability, and
the rotary table down from the milling section. I don't see a rotary
table listed, so you would have to get one from the Sherline folks to
have one of reasonable size.

I would probably take bayonet mounts from junk lenses and bodies. But
I can see that milling and a rotary table might come in handy for many
things. My father donated an old Unimat II (not threading, but it will
convert to a mill), and amazingly I have a very small rotary table
from a yard sale!

Great! I've never had my hands on a Unimat II, but the even
older Unimat SL-1000 and DB-200 have problems with rigidity, since the
bed is only steel rods supported only at the ends. If the Unimat II has
a cast bed, then it should be significantly more rigid, like my
Emco-Maier Compact-5/CNC. (Still not up to my 12x24" Clausing, of
course. :-)

The Unimat II is from the 60's and has rods supported at the ends, so
it will never be a great mill, but it may be good enough for some
learning.

It is an excellent little machine. Like all well-designed and
well-made lathes, it has a lot of capability within its designed
limits.

Bob Hatschek, a former Senior Editor of American Machinist and a
world-class model glider builder (who has flown all over the world in
competition), for decades made a little device known as the "Hatschek
Hook," a tow-release hook for competition gliders, on his Unimat II of
'60s vintage, sold them through the model magazines, and made plenty
of hobby bux with it. He used it for making all kinds of model parts.

So don't diminish its value and capability. It was a clever machine,
well-made, and it has a lot of capability.

If you're into this as a hobby, my suggestion is to focus on what you
*can* do with the machine(s) you have, rather than always pining for
another machine. You can get a lot of pleasure out of learning to get
the most out of basic machines. I decided years ago that I would
define my hobby interest in terms of learning old methods and doing
what I could with them. CNC was my business. It was not my hobby.

I can have a lot of fun with my 1945 South Bend 10L, with rocker
toolpost and all. I could have a lot of fun with a Unimat 2.

BTW, Hatschek uses music wire for a lot of his tools, including the
"production" tools used to make the Hatschek Hook from aluminum and
brass.

--
Ed Huntress





[ ... ]

And in addition to the listed things on that site, you will also
need:

[ ... ]

1) Micrometers in mm (since the lathe is calibrated in mm). At
the least 0-25 mm and 25-50 mm. The maximum capacity of the
lathe barely goes over 50 mm, so probably not the 50-75 mm one.

Yes, I only have an inch micrometer so far...

The 52mm specification is European style, giving the radius not the
diameter of the swing over bed.

That makes the range of sizes you can handle better. I was
thinking that it might be a bit tight for some sizes of camera, even if
you stick to 35mm ones. I'm used to "Centre height" being used for the
European style, and "swing" for the US style of dimensioning of a lathe.

Interstingly enough, the Compact-5/CNC is specified in Inches of
swing over the bead (diameter) even though it came from Austria.

Make that a four-micrometer set. :-) There are pretty good ones
(except perhaps for long term wear and retaining the accuracy) made by
the Chinese and sold at various places. The ones which I have seen
(four mic sets and 6 mic sets) have been inch mode ones, but presumably
they also make and import metric ones.

For one micrometer, a digital is nice for the ability to switch
back and forth between inch and metric. (But somewhat expensive.) I've
got two 0-1" ones, and one 1-2" one (each of the 1" micrometers is kept
near a different lathe, the 1-2" one near the Clausing. (The
Compact-5/CNC is a 5" swing (diameter, not center height). For beyond
that, I have a 0-6" set of Brown & Sharpe mics to cover to the max size
of the old Atlas/Craftsman 6" lathe I started with, and a collection of
Starrett ones of various sizes to fill things up to the 12" size.
(Though to be honest, *most* of the time, the 0-12" digital caliper
(Mitutoyo) is accurate enough. But if I did not have those micrometers,
then is when a job would come up where the extra accuracy would be
mandatory. :-)

Yes, I suspect that for most lens threads and such I could survive
with even 0.1mm accuracy, which should be easy even with a calipers.
For many other things "make it fit" is probably the order of the day,
and absolute measurements are not relevant. But I suppose that it is
inevitable that something will come along requiring a real number...


[ ... ]

4) A scissors style knurling tool to allow knurling parts for grip.
A "bump" style knurling tool needs a much heavier and more rigid
lathe to drive it.

Great idea; I hadn't thought of that.

I got my first one to use with the Compact-5/CNC -- way too
small for bump knurling -- and I really don't like it on any system. I
found a really nice one by Aloris to fit my BXA sized quick-change
toolpost . It has the two knurls on two arms which move in a vertical
dovetailed slide, each moving in the opposite direction with a leadscrew
with left-hand threads on one end and right-hand ones on the other.
Once it is set to the proper center height, I can just drop it on to
knurl any size within its range without having to re-adjust the height.

I did a little casual looking on the web and it looks like casual
looking is not going to do it.

There are many tools that will do up to about one inch, which is fine
for knobs but not so good for an 82mm filter ring.

Tools with large capacity probably don't fit on the small lathe.

Maybe a hand knurling tool is what I need.

However, it may be that no knurling tool is going to work well as the
last step on a filter ring because the ring is thin and will bend
under the load. Maybe I need to knurl first and then bore out the
center.

Bob



Enjoy,
DoN.