On 2010-05-16, Searcher7 wrote:
On May 15, 8:07*pm, "DoN. Nichols" wrote:
On 2010-05-15, Searcher7 wrote:
[ ... ]
I don't know if it was known that most of what I work with will be
plastic, brass and aluminum, with some light(finish) turning and
*threading* on S.S. rods).
* * * * Note that the 16N and the 16 are useless for threading. *They
are for turning/facing only. *You'll need some other form of holder for
threading.
Yup. I do have the basic tool holders, but they are the cheap ones.
http://www.shars.com/products/view/1...Wedge_Type_111
O.K. Without an AXA holder I can't verify whether the dovetail
fits the AXA or not. You do have at least one genuine AXA (14N was
it?), so you can tell quickly.
At least it is a wedge style toolpost, so it should deliver a
bit more rigidity.
But the main trick is to crank the compound back so the cutting
force is pretty much over the point around which the compound pivots.
The more you crank it out past that point, the more rigidity you throw
away.
I have some tooling for this package, but have to dig them out and
check what they are. I do have some boring bars.(Indexable ones also).
O.K.
I've probably been concentrating too hard on the 16N because my goal
is more toward the "all-in-one" holders so a minimum of changing time
is needed.(And of course I want to get the most out of each
insert). :-)
* * * * It is *not* an all-in-one. *It is a good general purpose holder
for roughing in both turning and facing -- but not what you want for a
really nice finish.
My meaning was that I wanted to move *away* from the single operation
holder. (And that AXA22 looks really tempting). :-)
It might be nice for getting uncommon edge angles (in 15 degree
increments IIRC, not *all* possible angles), but if I had one, I would
set it up for one specific useful angle and leave it that way. Whenever
you change the angle of the cartridge, you lose the benefit of the
indexable inserts and quick-change toolpost, and are back to having to
re-measure and set up for proper position.
* * * * There are a lot of things which you will eventually want to do
which require other holders and inserts. *You'll need boring bars and
holders for them. *You'll need threading holders and inserts, or plain
holders and appropriately ground HSS bits. *I think that with the lack
of rigidity of your machine, you will not be able to use insets for
threading SS -- and you don't mention *which* SS alloy. *Some are pretty
easy to work (e.g. 416). *Others will fight you all the way home (e.g.
304), but I think that any of them will require too much rigidity to use
carbide inserts with your lathe.
As for stainless. 316 and 416. (I do have some Aquamet lying
around,but know nothing about it's machinability).
Hmm ... 316 IIRC is one of the fairly nasty ones, but it is very
nice for rust resistance -- if you properly passivate it after turning
it. Anywhere that it touches steel (e.g. the chuck jaws) will be a
place where rust will start. And I don't think that you can handle the
passivating chemicals in an apartment building.
And -- with 316, you are probably in one of the the serious
work-hardening alloys. If you don't have the rigidity and power to keep
it cutting, as soon as the tool starts to skate on the surface, it will
harden the material so it will be *very* difficult to re-start the cut.
* * * * I tend to use an extended holder with my insert tooling for
threading.
There are so many tool holders that it can be overwhelming. I'd hate
to get one only to find that there was a better option.So I'm looking
at the "Universal tool holders" to see what is possible.
http://www.aloris.com/catalog/aloris_p10-11.pdf
* * * * Those are nice when you need an edge at a particular angle and
don't want to have to shift the toolpost from its proper
square-to-the-axis position. *But for general use, you would spend so
much time adjusting the angle for different things that would be better
spent dropping another holder in place for the task.
But I figured it would be more difficult to get precise angles when
using the normal H.S.S. holder/bits.
How are you going to get a precise angle which does not fall on
the standard multiples of the detents of the cartridge? Re-checking the
PDF file which you pointed to, it moves in 15 degree increments.
If you want to *cut* a specific angle, you set the compound to
that angle and feed in along that angle. These could be some help in
that (fitting where you need to go), as long as you don't need an angle
below 60 degrees (the angle of a triangular insert). For narrower
angles, you'll probably need one of the diamond shaped inserts. One
common size has a 55 degree angle (not much better than the 60 degree
triangular). Another is a much sharper angle, but I would have to look
it up to see what it was.
Having lots of HSS bits on hand, and a bench grinder will allow
you to make tools to fit what you want to do. Bear in mind that your
lathe will not have enough rigidity or power to handle form tools under
most conditions.
* * * * The purpose of quick-change toolposts is to save you time, to
make you more productive -- *not* to save you money in buying tooling.
Well, if saving money were the *priority* then I'd stick with only
H.S.S. :-)
:-)
(Of course H.S.S will still predominate on this lathe). :-)
* * * * And it will probably be the only thing which you can use with
the SS above.
O.D. threading those 3/8" to 1/2" dia S.S. rods are just a single
"extreme" job for this lathe.
They will be "extreme" all right -- especially the 316.
How long a thread do you need to make? If it is any longer than
about four times the diameter (e.g. 1.5" for 3/8" diameter) you will
need to support the other end with a live center (which may get in the
way of the threading), and if it is more than about double that, you
will also need a traveling steady rest to keep it from bowing away from
the tool in the middle of the length. (Do you have a traveling steady
(also called a "follower") for your lathe?)
I was only thinking of insert tooling as
a *possibility* for when/if I couldn't get the H.S.S. bit angle right
for consistent threads. It basically comes down to what would be
easier and more efficient.
The angle will be right for the insert threading tools, but
unless your rigidity is greater than I expect, you may wind up breaking
lots of inserts. (And there are no positive rake threading inserts, so
three corners is all that you get per insert. :-)
Threading plastic should be fine. Threading a free machining
mild steel (e.g. 12L14) should go fairly well if you don't have too
coarse a thread. (Your main trouble with those small machines will be
getting the machine to go slow enough to let you disenage the threading
feed quickly enough as you approach the end of the thread.)
However -- threading Stainless steel is going to be tricky with
your machine. I've threaded 416 SS without problems. But I'm not at
all sure what would happen if I tried 316 SS. I don't have any, so it
does not matter at the moment.
What do you *need* to thread SS for anyway? I thought that you
were mostly talking about making parts for video games.
Good Luck,
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 ---