On 2009-09-26, Michael Koblic wrote:

"DoN. Nichols" wrote in message
...

[ ... ]

Hmm ... 1.5" diameter is probably a pretty good size for some
projects -- especially lathe ones. You'll want to get as long a rod as
you can afford/(transport home) and have some way to cut it. The
typical 4x6" horizontal/vertical bandsaw works well for this.

[ ... ]

Hacksawing is one of the ways I get exercise.

Well ... with 1.5" diameter, you may get tired of that fairly
quickly. And the H/V bandsaw makes a cut closer to square than a
hacksaw typically does. You still have to face it to clean up the cut,
but there is less to remove after the bandsaw has done its job.

However, even with such exemplary lifestyle I doubt I shall live long enough
to machine anything out of a 1.5" bar on the Taig, 0.005" at a time. I made
further enquiries with that wonder of a company, Fastenal. Their catalog
shows only the 1.5" round in 12L14. A phone call to the branch here in town
revealed that they could get 3/8", "but 10 feet length would be below the
minimum order". The same company, branch 50 km away, can apparently sell
single 3 ft rods of 3/8" just under $8.Which in US sells under $3.

Hmm ... if they have to order it in, yes, they want to sell it
all at once to make it worth their while.

As for the 3' rods -- get *one* (if that branch does not also
have a minimum order) and see what it is like to use it. I think that
you'll find that your Taig can cut deeper than before. And also get
some 360L brass as well. It is lovely to cut too.

[ ... ]

O.K. Yes the finish varies with the intended function. Black
oxide is nice for some materials, Polished parabolic flutes nicer for
others, TiN coated for letting the chips flow out from yet others. My
usual bits (the 118 piece set of number/letter/fractional and the cobalt
steel set of number-size screw machine length bits are both polished,
though not parabolic flute. The two sets which make up my stock of
metric sizes are black oxide, and I don't use them often enough to have
an opinion for my usual materials. My metric tap-and-drill set has
everything TiN coated, but Cleveland brand bits and taps, so I know that
they are good.

[ ... ]

I got a black oxide set of 118 degree point stub drills specifically for the
Taig. They cut incomparably better in steel than the CT TiN. The chips come
out of the holes ever so easily even if the hole is quite deep. The TiN cut
for about 1/2" and then the chips stop flowing and the rubbing starts (I am
talking certified mild steel now). No amount of lubricant seems to change
that.

I think that this says that the Chinese bit is "certified mild
steel" as well. :-)

As for "lubricant" -- what are you using? You really don't want
to lubricate -- you want to cool (remove heat from the tool and the
workpiece), and to chemically aid the peeling of the metal away from the
workpiece. Things like Rigid high-sulfur pipe threading oil will work
sell for the purpose.

[ ... ]

Was the workpiece hollow or solid metal? If solid, check
whether your drill press vise has a horizontal V-groove, ideally with a
Vertical one meeting it in the fixed jaw. These give a good grip, and
the vertical V-groove gives access to the area which you want to
cross-drill. (For that matter, you can take a short piece of material the
same diameter, face off the ends and drill through the center just the
size to accept the drill bit which you intend to use, and drop it down
the vertical V-groove after inserting the workpiece in the horizontal
V-groove. Then Tighten the vise and drill guided by the existing center
hole. (If you're going to drill a lot of holes like this, make the
guide out of drill rod, and harden it after machining (facing and
drilling), so it will last longer. Probably a good idea to use a
countersink to chamfer the hole at the upper end at least -- and
probably both ends so you don't have to worry about which end is up.

It was solid. Yes, there is a horizontal v-grove but the 5/16 diameter
cylinder

Hmm ... the fact that you keep calling it a "cylinder" instead of
a "rod" is probably why others in this thread have assumed that what you
are drilling is hollow and commented on how the bit behaves as it breaks
through the inner walls. Try calling it "rod stock" and people won't
make that assumption.

all but disappears in it and the vertical groove is not large
enough to allow 3/16 drill through. Also, I am not sure how one would center
the drill if the piece were held this way. Can you be certain that the
vertical groove always centers automatically on the diameter of the piece
held in the cross-grove (which would be mandatory if one used the guide made
as you suggested)?

Well ... Both V ways were probably cut on the same machine, so
the depth should be the same. A quick check is whether both the
horizontal workpiece and the vertical guide (which for test purposes can
simply be another cutoff of the same stock) are firmly gripped by the
vise at the same time. It probably does not hurt to add paper between
the moving jaw and the workpiece and guide to make up for the jaw
tilting slightly as it is tightened.

I used to drill similar pieces held in the horizontal v-grove *before* I cut
them off. I tried to let them stick out to the side of the vise which
allowed for proper centering and center drilling. Even then, the problem was
that one had to let the piece stick out quite a bit to be able to get the
chuck down to the piece without the top of the vise interfering.

Two identical vises, clamping on either side of the area where
you intend to drill.

If you are supporting only at one end, consider that if the
distance from the clamp (vise) to the place where you are drilling is
over four times the diameter of the workpiece, then it will flex. (Same
rule should be used for work held in the chuck of the lathe. If it
extends beyond that length -- add support by a live center in the
tailstock to make it more rigid.

This was
all well and good for center drilling but when one came to use the twist
drill more chatter and rubbing resulted. I tried making an improvised
machinist jack to support the end sticking out but it did not seem to help
all that much. Mind you, it was a pretty miserable excuse for jack !

A chunk of round stock, drilled and tapped down the center to
accept a bolt. Turn a point on the head of the bolt, and make a piece
with a center hole in one side, and a V going across the center of the
center hole )look for it to break through there) can be used to support.
The greater the diameter of the base of the jack, the more stable it
will be.

With the advent of Taig I was hoping that these problems were a thing of the
past now that I could face off the opposite ends of the cylinder. Apparently
not so.

Use the cardboard for crush space to increase the grip.

[ ... ]

What you want for the Zen quality is a small shaper -- say a 7"
one. You sit there watching the ram move in and out, with the workpiece
moving sideways just a little during each backstroke. And the tool is a
simple HSS lathe bit which you can grind as you wish.

Due to recession I shall have to stay with the Taig and chanting a mantra.
BTW I wonder if one can make a mandala out of the steel wool and assorted
chips.

Well ... you are unlikely to be presented with the opportunity
to buy a new 7" shaper. You have to luck into a well used one. Nobody
seems to make them any more.

Enjoy,
DoN.

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