According to :
DoN. Nichols wrote:
According to :
[ ... ]
Actually most of the parts in question will be enclosed most of the
time but the device will be opened up frequently for adjustments.(I
just don't know if S.S. 316L would be over-kill).
I think that it is serious over-kill -- and it might not be the
best material for other reasons, such as difficulty hardening it by heat
treating..
I won't have to worrry about that. But since this is a unque kind of
videogame joystick, I'm more concerned with the sweaty hands of a gamer
who will have to open up the top to change certain settings.
Are these settings necessarily part of the joystick, or could
the controls be mounted somewhere else?
My
original concern was involved the ball bearings that would roll against
the S.S. plates, but I redesigned it so that there will be no friction
to worry about between the chrome steel bearings and the S.S. Wherever
there would have been friction between metal parts, Delrin was
substituted, so that now the only contact will be between Chrome
steel(bearings) and Delrin, Stainless steel and Delrin, and Delrin and
Delrin.
So -- just wipe the steel part down with a good thick lube like
Vactra No. 2 Waylube (which you'll need for your lathe or mill anyway).
[ ... ]
For this particular operation the work will be 4-1/2" x 4-1/2".
Hmm ... and the round depression is centered? This could be
nicely done by a lathe. Let's see -- 4.5" square means that the
diagonal would be 6.36" diagonal, so a 7" lathe could handle it, if it
had a 4-jaw chuck which could extend the reversed jaws out far enough.
Ok. A 4" diameter(1/16" thick) Delrin disk will be placed into that
hole.
O.K. Any reason why you can't use aluminum for the square
plate? Aluminum protects itself by quickly forming an oxide coating
which prevents oxygen from the air reaching it to continue the
oxidation.
Since you no longer need it to be a bearing surface (the Delrin
is doing that) you should be fine. And a good aluminum (say 6061-T6) is
quite nice to machine.
[ ... ]
An end mill in the lathe's spindle (in an end-mill holder) and a
milling adaptor replacing the compound to allow vertical adjustment of
the workpiece. The square could be accomplished with just this, but
what would make it easier would be one of those collet sets which holds
5C collets in either a square (for four sides) or a hex (for six,
obviously), which could be held in the vise on the milling attachment
and be rotated one flat per pass to produce the desired square end.
So I guess that one of the 7 x 10 or a 7 x 14 mini-lathes by
Micro-Mark, Central Machinery, ect. would work.
As long as you can get a milling adaptor for the cross-slide.
So it seems that
instead of entertaining what the shortcomings are of a drill for
conventional mill work, I should have been making comparisons between a
Mill and a lathe.
Yes -- with the understanding that it will be more convenient to
have both eventually.
(And that is just
one of several "square" parts involved in my first project). That is
why a mill-drill is my first choice at this time. It would seem easier
to use a mill as a lathe instead.
That latter depends on the mill. First off, you will need some
kind of workpiece holder (like a chuck) to fit the spindle (and a larger
spindle is better here), and a good way to hold a cutting tool.
Or -- you could mount the workpiece on a rotary table, and
*mill* the workpiece to shape as you rotate the table.
It looks like I'll be spending a lot of time on the lathe pages at the
website for Harbor Freight and Grizzly. :-)
O.K. Not exactly the best of machines, but probably closer to
your budget for the moment.
And -- make sure that you get a 4-jaw chuck for your square and
rectangular workpieces.
Remember that my size calculations were based on the assumption
that the circular depression (I would not really call it a "hole" at
that depth to diameter ratio) was centered. (Pretty much has to be,
given the size of the depression relative to the overall size of the
workpiece.)
It would be a lot easier to explain the limitations of each
route if you already had experience in using the basic tools, and you're
trying to decide which tools to get, so you don't have that experience
yet.
True. But You've taught me a lot. :-) I was just getting ready to get a
small mill, but now I will look harder at the lathes.
O.K. Understand that I have several of both lathes and mills,
in different sizes.
*** It seems to me that once I account for the 3-dimensional(LxWxH)
workspace(maximum size of the work piece),and all tooling, jigs,
tables, and adapters for both a mill and a comparable lathe, I should
just ask what *can't* be done by one machine that the other one can
do.(I'm not really worried about what is "easier").
O.K. Sometimes, the decider of whether it can be done or not on
the "wrong" machine is more whether the machine is large enough to be
"abused" in that way. Also -- what tooling you may have around to adapt
it is important.
Good Luck,
DoN.
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