In article ,
"DoN. Nichols" wrote:

I had to fold the "References: " header again. It got too long for
jove to accept on a single line. :-) Then I had to create my own
} Message-Id: because that was where jove was snipping things off
when following-up.

Perhaps we should start trimming the end of the References
header every reply if we're going to keep this long a thread going. Of
course, it will mess up threading, but at least it won't hit the 1024
byte line length limit on jove -- or force me to move to emacs. :-)

I never delved into how the threading mechanism works, and the nesting
gets pretty deep and sometimes complex, but perhaps there is a clever
way to prune.

Perhaps it's best to start a daughter thread of the same title.


On 2008-05-09, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:

[ ... ]

O.K. And if the tip has a shallow 'V' in the top, it will make
the chip narrower than the slot, to reduce the chances of catching.

Yes, although I have not had that problem if I can prevent self-feeding
and overly thick chips.

O.K.

Most of the stuff I would cut off are not that large, so a narrower
blade is also useful, and it reduces the force causing all the problems.


I've been looking for a cutoff tool that can be used in front, but with
reverse rotation. The BXA7R doesn't actually work for this, instead
being intended for use on the back side of a forward rotating workpiece.
What is needed is the mirror image of a BXA-7, versus an upside-down
BXA-7.

So -- make your own using the design of the Aloris one. The
main trick is getting the dovetail width and depth right. The trick for
measuring the width is to measure between two pieces of drill rod pushed
into the 'V's.

Hmm. The BXA-7R would be a lot of trouble to duplicate in full, but it
is certainly practical to duplicate the BXA dovetail, allowing me to
make special BXA toolholders.


I've also been looking at the Aloris holder for SGIH blades, BXA-77.
However, it isn't clear that one can use upsidedown blades in this
holder, as the bevels on the blade are not symmetrical.

Perhaps the best solution is to install a cutoff tool bar with
rectangular shank upsidedown in a regular tool holder.

Perhaps. Or make something which you can clamp in the regular
holder but which will hold the blade of your choice upside down.

I received a somewhat beat up Hardinge C31 cutoff blade holder with the
lathe. The C31 is designed to be clamped in the slot of a toolholder in
their CHNC line. Google for "HARDINGE CHNC TOOLING.PDF".

Nor would it be difficult to make one's own mirror image C31. The only
problem with this approach is the large overhang, 3.5" versus 2" from
the center of the 5/8-20 bolt clamping the toolpost to the slide.

One could make a mirror-image C31 with a BXA dovetail, but the two
designs are pulling in different directions. The C31 has a very deep
horizontal slit which closes slightly when two hex socket cap screws are
tightened, thus bringing the top and bottom of the blade groove
together, clamping the blade. The bending caused by clamping would tend
to distort the dovetail, unless a second slit were provided. The second
slit would orphan part of the dovetail. This needs some design analysis.

I think I'll also troll in the catalogs of BXA-compatible toolpost
vendors for ideas and/or products.


[ ... ]

Thumbscrew? Mine came with hex socket cap machine screws riding on
brass slugs. Hmm. The 5914 manual shows knurled thumbscrews, also
riding on brass slugs. So both thumbscrews were lost and replaced.
The
cap screws are clumsy to use.

Mine had one thumbscrew and one cap screw, so I ordered a
thumbscrew along with the leadscrew and T-nut for the cross-slide.

I may do the same. I'm close to ordering a T-nut for the cross-slide
screw.

They were pretty cheap when I got mine -- at least by comparison
with everything else which I ordered. (Oh yes -- the felts for the
carriage-to-ways interface were pretty cheap, too.

Felts. The left front carriage wiper always leaves a black dirty-oil
trail in the bed way. Solvent cleaning didn't help, although continuous
flushing by over-oiling with Vactra #2 is helping.

I should see if the black is coming from the carriage versus the felt,
as I have not yet disassembled and cleaned this part of the lathe.


[ ... ]

Yes. I guess that more of the Logan lathes were sold in the
hobbist size range, so we don't see the larger ones coming up on the
used market very often.

Actually, one did go by, at Gold Machinery in Rhode Island, but before I
was ready to buy anything. So did a Clausing 5914 for that matter.

Gold's reputation around Boston is that they are expensive, but have
good stuff. http://goldmachinery.com/machinery/index.htm

O.K. I'm retired too long to have the money to buy more large
tools, so that will simply be filed in memory somewhere in case I win a
*real* lottery instead of all the fake ones I get e-mails about. :-)

Who knows. Maybe that nice man from West Africa will arrive with the
$20 million he promised. Maybe.

More seriously, I'm wondering if the more expensive machine might prove
cheaper, as I will probably end up spending the difference on new parts.
Although it has certainly been educational.


[ ... ]

Mine was $200.00 on eBay -- and cost more to ship down to the DC
area from the Boston area. :-)

That's a bit of a drive. How much did the shipping cost, and what year
was this? Perhaps I should have considered non-local sources.

I don't remember for sure, but I think about $240.00. And this
was back around 2000 I think.

Even with eight years of inflation, not such a bad price. One problem I
had with getting stuff from Gold Machinery was the distance. Perhaps it
was not as big a problem as feared.

Perhaps. But the prices will probably change on a day-to-day
basis with the fuel costs.

True enough, but probably not the biggest cost.

Joe Gwinn