In article ,
"DoN. Nichols" wrote:

On 2008-02-22, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

On 2008-02-21, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

On 2008-02-21, Joseph Gwinn wrote:

FWIW, I just measured the thickness of the original T-nut for the DuMore
toolpost grinder, and it was 0.187". I would have simply left
the one which I made for the Clausing on it, except that it does
not fit under the bridge which supports the toolpost mount in
the case. This is not one of the cases with the hinged front
panel, but rather one with a single hinge at the back.

To take the grinder out you have to:

1) Loosen the nut on the mount rod.

2) Tilt the motor towards the toolpost column against the
spring which keeps the drive belt tight.

3) Slide the original T-nut out from under the bridge.

4) Swap the supplied T-nut for the one made for the
Clausing.

5) Tighten the nut to hold the toolpost column down.

6) Loosen the clamp bolt and slide the grinder off the
column.

7) Slide on the height spacer, and replace the grinder
on the toolpost column.

8) Fit a belt.

9-66 or so) fit the stone, dress it, and do the actual work,
including cleaning the ways of whatever snuck past the
protective covering.

I've already had the grinder partly apart, but have not yet tried to
mount it on the lathe. I have to fix the overheating-spindle problem
first.



Wouldn't a bridge crane be more useful?

Not without a place to mount it. I have a folding engine hoist,
which lives out in /dev/barn01 when I don't need it, because I don't
have enough floor space in the garage^H^H^H^H^H^Hshop.

I looked at portable bridge cranes, such as sold by HF, but my ceiling
is too low. Nor do I have a place to store an engine hoist, so I rent
one from Taylor Rentals when needed, for ~$45 per day. The rental unit
is far heavier than the $170 HF units.

The height problem is another point. The lathe is under a garage
door which bends in sections and stores above the lathe. :-)

Right. My reason to investigate the bridge crane is that the legs on
the typical shop crane can very much get in the way. A bridge crane
doesn't get in its own way nearly as badly.

O.K. I can see that -- but there are too many tools, and too
few square inches of bare floor left. :-)

Ditto.


And can pick things up directly off the floor and raise them to full
height in one operation. The rental shop crane could only lift things
about 3 feet at a time, so one needed to rest the thing on something and
reattach it to the crane with a shorter chain.

O.K. If I tried to lift more than three feet, I would have to
make a hole in the ceiling, and my wife would be quite displeased, as it
would also be a hole in the floor of the room which both of use spend
most of our time in. :-)

And most bridge cranes are big enough that one can use them to move
machines to and from the bed of a flatbed or pickup truck.

Again -- not an option in my shop, with so little clear floor
space -- even if I had the height for the bridge crane.

The other advantage of the engine-hoist style is that one can lift
closer to the ceiling. With bridge cranes, the highest one can lift the
hook is something like 15" or 18" below the top of the crossbeam, while
a hoist can put the hook about 6" below the ceiling. This is a big
difference in a shop with a low ceiling.


Some of these days, I've got to get a couple of friends and
spend a day rearranging the tools to get the mills closer together, and
move the grinders away from such precision tools. :-)

I'm already somewhat separated, with grinders in one room and the lathe
plus mill in the other. This was dictated more by space than by smarts.


O.K. It was helpful to have the surface grinder for making the
Acme tools with precisely the proper relief angles for the pitch and
diameter I needed to cut. Also a sine plate and a sine bar contributed
too.

That's pretty ambitious. I think I'll just buy Acme thread inserts and
holders if the need arises.

That's what I normally do -- but I've got the largest insert
holder available to fit into my Aloris tool holders, and the inserts
which fit stop short of the acme thread which I had to cut to make a
replacement nut for a friend's leadscrew-driven log splitter. He
ordered a good bronze for the nut, and I made both a dummy external
thread to duplicate the one in the spitter, and then the internal thread
in the nut. For that -- it was a choice of grinding freehand, or using
the surface grinder, and the latter gave me more control of the
clearance angles to match them to the thread which I was cutting. The
external thread was cut with a standard 1/4" HSS bit held in the Aloris
holder, while the internal was a 3/16" bit held in an old boring bar
which fit one of the boring bar holders for the Aloris toolpost.

OK. What acme thread were you cutting? Given the delicate nature of
the application, one assumes that this leadscrew is quite dainty.

Shouldn't this been the excuse to buy a larger insert holder and insert?

Joe Gwinn