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Default Trepanning and Parting Off -- part 2

On 2008-05-10, Joseph Gwinn wrote:
In article ,
"DoN. Nichols" wrote:


[ ... ]

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.


Well ... my approach -- pre-folding the header and starting
every extra one with a tab at the left margin was too successful. The
system accepted it as a properly folded header, and straightened it out
again. I've folded again, and after the first few, I've introduced an
"X-References: " header

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


We would have to edit out the existing "References: " to make it
be accepted as a new thread.

Essentially, the newsreader takes the "References: " header's
contents which represents a long string of messages, gets older messages
by "Message-Id: ", and finds all of the articles which reference those
to build up the full thread tree.


This sounds like far too much effort compared to spawning daughter
threads as needed.


Editing out the "References: " headers is easy (at least in my
newsreader), and I've modified the "Subject: " header too to start from
scratch with this one (if you spot it by "Subject: " header, at least. :-)


Of course, Windows newsreaders (like OE) and some others simply
use the "Subject: " header contents and ignore the "References: "
totally. And -- they also Take any two-character start to the Subject
header which is followed by a ':' and delete it, replacing all of them
it finds with a single "". It assumes that anything of that format
is "" in some language or other, which results in attempts to mark a
thread as off-topic by prepending "OT: " to the "Subject: " header
results in it being stripped off the first time it passes through OE. :-(


Another bit of evidence of MS's deep respect for standards.


Of course -- if people would stop using the ':', it would work
as desired.


Of course, in English syntax anyway, the colon is the correct
punctuation mark to use.


Right -- but in Subject line syntax, as implemented by
Microsoft, it is unfortunately not. :-)

[ ... ]

So -- make your own [blade holder] 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.


Yes -- and you could make a rear-mounted toolpost whose sole
purpose is to mount a parting tool, so it does not have the two
dovetails, just the one, and can be locked by pulling in the rear
dovetail (the one away from the centerline of the spindle) with a
through bolt and a nut, since it does not need to be quick change. This
could get the blade a lot closer to the bolt which holds it down. You
could even pass that bolt partially through the dovetail -- and give the
rear post a foot which extends under the actual parting tool to make it
less likely to tilt under cutting forces.


I can visualize a number of ways to do this, but they all sound a bit
over-extended and floppy. I think that if I make anything, it will a
for front-mounting an upsidedown blade, to be used with lathe in reverse.


The design that I had in mind would neither be over-extended nor
floppy -- but it requires a cross-slide with back T-slots. (Such were
made for the Clausing lathes, and were often supplied with the
turret-equipped ones -- but would be unlikely to be used in reverse with
the original threaded spindle on my machine. (It came as 2-1/4x8
threaded, and is now L-00 thanks to a spindle transplant.


Of course -- you would want a cross-slide which had rear
T-slots to do it properly.


That's the problem. I have the ordinary one-slot tool slide, and it
does not have the reach to allow use of rear parting tools.


By "tool slide" I'm used to reading that as the slide on the
compound, not the cross-slide. The compound is not involved here --
just a cross-slide with an extra T-slot or two along its length,
including at least one at the back. And the standard cross-slide (or at
least mine) does not have a straight T-slot at all -- just a circular
one around the stud on which the compound pivots.

[ ... ]

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".


O.K. A starting point. It will go in the slot of a BXA-1 won't
it?


It will. The attachment stub plate is 0.438" thick (the clamping
dimension) by 0.5" deep (into the BXA-1 slot) by 1.25" long.


O.K. That gets you started.

[ ... ]

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


O.K. Though I'll bet that you won't find much in the others
which is not in the Aloris catalog.


Yes and no. Phase II and DTM seem to have only a subset of the Aloris
range, but Dorian Tool in particular seems to have their own ideas and
products.

I'm looking at the Dorian D30BXA-7-71C, which looks capable of full
reversal and is it's own mirror image, looks like the best bet.

The Dorian D30BXA-771, which is billed as "universal" but not
reversible, seems less suited to use with upsidedown blades.


O.K. I'll take your word for it. Hmm ... I wonder how many
Dorian toolposts and holders show up in eBay?

[ ... ]

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.


What happens if you remove the felt from under the cover and
just squish it in a vise or in pliers? Does it squirt out black goo
then? If so, then it is time to purchase or make replacements. Start
with an arch punch to cut out circles of the right diameter, then a
guillotine to cut the flat on the bottom and a leather punch to punch
the screw hole, and you can make new ones from high density felt (which
you can get from MSC or McMaster Carr in lifetime supply quantities (and
only in such quantities. :-)


The felt is very hard, and does not squish. I think it is solidified
with hardened cutting oil. I bet I have the original felts all around.


Ouch! New felts needed for sure. If it is hard, it could pick
up abrasives and abrade the flame-hardened ways.

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 -- you should. If it is coming from under the carriage,
then it suggests that the carriage ways are worn into a shallow arc,
which could contribute to your chatter problems. Then it would be time
to look for a replacement on eBay, or to explore the special compounds
used to make replacement ways. Ah yes -- "Moglice" is the name, I was
struggling for it for a bit. :-)


Hmm. I don't think that this is a significant problem, but I'll test
for this. The simplest approach is to mount a dial indicator on the
carriage with the indicator probe tip riding the the flat tailstock way,
and crank the carriage back and forth (to test the bed ways) and torque
the carriage for-and-aft with a bar in a boring bar holder (to see if
the bottom of the carriage is shaped like a boat hull).

I would think that the rocking would be constrained by the hold-down
plates.


It doesn't take much -- and given enough time, the hold-down
plates would wear in a matching pattern, which would control straight
lift, but which would allow the rocking towards the headstock and
tailstock.


[ ... ]

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.


Have you noticed that the recent ones (or at least some of them)
*admit* that the previous ones were scams, and purport to be the
government of Nigeria trying to set things right. :-)


I've seen those. And the ones that purport to come from other than
Nigeria, but have the same story and sure sound like Nigerian English.
And often use all caps.


It is usually Nigerian citizens resident in other countries,
even the Scandanavian ones, and certainly in the UK. (This all based on
the IP addresses from which they are delivered. Unlike other spams,
these 419 scams need to give you a way to contact them. :-)


Retirement is a few years away for me.


Good luck with that.

[ ... machine transporting ... ]

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.


It may well be just that at today's fuel prices -- especially
bearing in mind that diesel now costs more than gasoline.


Well, it will be at least a year before I contemplate buying another
machine, and we will have a different set of problems by then.


O.K. It would be nice if fuel costs fell back down a bit.
(Actually, I would *love* for them to go to where they were when I first
started driving -- $0.25/Gallon. Three dollars' worth would fill the
tank on my MGA. :-)

Enjoy,
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 ---
 
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