"Bill Schwab" wrote in message
link.net...
Harold,

If you do any wood work on the machine (not all that uncommon), make
sure
you don't leave any damp chips behind. I've used my metal cutting
machines
for that purpose countless times with no problems, but I clean up well
afterwards.

The plan is for lots of woodwork in addition to simple electronics
fabrication and, over time, lots of Al plates with tab A one side and
slot B on the other.

Is there such a thing as a preferred end mill for mortising?

Chuckle! Mortising? If you could see my red face (embarrassment), maybe
you'd understand.

I hate wood work, and I know almost nothing about it. I'm not sure I know
what a mortise is. The wood work I've done is for pattern making, and I
work like a machinist, not a wood worker.

End mills are available in a huge array of configurations, starting with
stub models that are intended for slotting, right up to the long ones (dies
sinks) intended for milling large faces or deep pockets. I think the best
advice I could offer is to buy that which best serves your purpose, and
restrict their use to wood alone. Once you've run a metal cutting tool on
metal, that fine edge you need for machining wood without splintering is
gone. Carbide end mills are now cheaper to buy than HSS, something I am
still struggling with. It goes without saying, they'll serve you better
than HSS will in the long run. Choose 2 flute cutters for wood, not 3 or
more. Run them flat out---even if they're HSS. You won't be over driving
them.

If you have a choice, carbide should be a C2 grade, best for wear
resistance, and the choice for almost all non-ferrous use. If they're the
newer carbide (micrograin), you may not have a choice, but anything you get
will perform quite well, especially in wood. Look at machining wood much
the same as machining aluminum. Greater chip relief is desired, as well as
more generous cutting reliefs and rake angles. HSS end mills are available
with grinds for aluminum, and they are generally marked clearly on the
shanks if they are. They have greater relief angles, and often polished
flutes, so they are better suited for wood than would be steel cutting
tools.



Speaking of the table, most of it is quite clean. There are a couple of
small dings that I assume will be best honed or lapped away. What
should I _not_ do?


If you're familiar with draw filing, that's the way to remove dings on a
table. A single cut file (best not a new one, which is usually quite
aggressive) is placed on the table of the mill and drawn sort of
sideways
along the table with light palm pressure on the file. Given the proper
application, it glides over the table with no consequence, but removes
anything that stands above the table. Cast iron is very good about
cutting
away easily, unlike steel. If the file traverses the surface smoothly
and
doesn't hang up on anything, the table is clean. If anything stands up,
you'll feel it. Just repeat the process until you don't. You'll be
able to
see where it was, and how it was removed to flush with the balance of
the
table.

My first attempts will be on some test pieces vs. the table, but that
sounds like a plan. With some luck, my table saw might have a blemish
in a harmless location.

Key is the file, which must not cut aggressively. I've posted more comments
on this addressed to Karl. I really don't recommend a stone, although it
certainly can do the job, albeit with a caveat.


Before even checking prices, I knew about the tool change, head height,
registration woes of round column machines. I can live with it (670
pounds was quite sufficient for me and my engine hoist), but will
welcome ways to reduce the hassles.


Think ahead, and make sure that once you've established location and
have
your dials related to the part, make sure you don't have to move the
head.
Know what tools you're going to use, and make sure that the long ones
can be
installed and used, as well as the short ones. Where you get into
trouble is
using end mills in collets, then changing to a collet mounted drill
chuck
and using large, long drills and reamers. You run out of spindle,
which is
the chief reason I hate mill drills. On knee mill, you can move and
not
lose registration. (Not trying to be rude here)

No offense taken. The whole time I was wrestling the mill over the 30
ft from my driveway to its current location, I was feeling pretty good
that I did not go for the knee mill, at least not right away - not that
I would even attempt to move one myself.

Moving such things isn't a problem if you incorporate some pipe (and it's on
concrete). Once you have a machine on a few pieces of pipe, assuming you
have concrete as a floor, you can move it anywhere you desire, usually
without assistance. You have to keep juggling the pipe as it moves under
the rolling machine, so having extra hands can be useful, but not necessary.
You can move a machine that weighs tons by that method.


One of the more interesting suggestions was to use a collet chuck. My
problem is that google returned so many hits as to be useless. Can some
kind soul who knows what is going on provide a link to the right gizmo
(or refute the idea)?


Unless you intend to stay with the machine for the unforeseen future,
or if
you intend to use it for gain, where time is important, I think I'd
stick to
collets and not worry about it. One of the negatives of using any
kind of
quick change is that you generally add to the length of the spindle,
costing
you rigidity unnecessarily, but even worse, valuable space. You'll
have
limited height to begin with. I'd strongly recommend you not reduce it
any
unless you have good cause.

I suspect that where it matters, I will have height to burn because the
parts will be small. But I could be in for a surpise.

Yep. All depends on the work at hand. I don't care how large one's
machine may be, a job always comes along that won't fit. Murphy's law!
Still, in general, I understand your comments and agree. Sounds like
you've given this some good thought before jumping.



An edge/center finder is on its way. For most things, layout lines will
probably be more than sufficient. Otherwise, I am thinking of
drilling a reference hole for "when" I get lost, and then working
relative to it.


Not in your table! Good machinists don't drill holes in
machines------especially not by choice.

I've never knowingly drilled a hole in a machine (I once discovered one
in a shared vice and had to wonder) and have no plans to do so. Rest
assured I mean a reference hole in the work piece.

Cool! You do understand! g

You don't really need that reference hole, not as long as you have some
fixed datum points as I suggested. If you had to make parts to print,
you'd understand that you're not always at liberty to stab in a tooling
hole, so you learn to work from surfaces that are available to you. In
keeping with that thought, when you do multiple pieces, it's really nice to
hold them identical in size (deduct from that, *on size*, not from one end
of the tolerance to the other), even when it doesn't matter. That way you
can use any edge as a reference point, a situation that often arises.
That's all a part of the things you learn as you progress in the trade.
Might not make much sense to a beginner, but it will the first time you
encounter a problem that can't be otherwise solved. I have the T shirt on
that one.




As long as you have a method of
locating your part as it relates to the spindle, just make it a habit of
always doing it a particular way. Should you get lost, you can go back
and
start over. You'll use your edge finder or a wiggler, or even an
indicator, depending on the setup. That's no different from a hole,
which
you'd have to relate to in the same way. Lost in this? Did I not
understand the hole concept? Maybe you have a thought that got past
me.

Only the bit about drilling a hole in the table I'm following fairly
well, but am not sure about using a dial indicator to locate relative to
the part. It sounds like a good way to go. In studying the mill, I
have been getting ideas of making some kind of clamp to grab the
head/spindle/quill/column to hold an indicator. Is it easier than that?

Oh yeah! An indicator held by anything but the spindle won't help you make
setups as they relate to the spindle. You can find center of anything that
you can span using an indicator. Even square or irregular stuff. Hex,
octagon, etc. You can locate dead center of a shaft, or your vise, and do
it reliably. Using the drill chuck, as you've already suggested, you
sweep sides of items, locating the low point, then make them identical @ 180
degree intervals---which often necessitates moving the indicator off the
part by raising the quill so you can index to the opposite side. It's like
sweeping a bore, but working on the opposite face. Get creative. There's
really no rules on how you can use your DTI---and it doesn't matter if you
introduce error by offsetting the probe-----not as long as you're making
comparative readings, one against the other. You don't care if the reading
has any particular value, you're just trying to get surfaces to read the
same. Center.


The indicator could be on the table, but how would I create or find a
good target on the spindle? There are very few flat surfaces up there,
and I fear the curvature would make for large errors.

See above. You work *from* the spindle.

So far, I'm even a little nervous about even having room to change
collets over a work piece. That might complicate using an edge finder.
Milling with the spindle significantly extended probably has a role
in the solution.

In wood, or aluminum, that's likely to be fine, but keep your quill as short
as possible at all times. That keeps the machine in the most rigid
posture. Being a mill/drill, you'll have to compromise on that, but it's
not likely to be a big deal unless you use some large cutters, or take some
unreasonable cuts. Non issue in wood.



Lets talk about it. If you aren't familiar with typical shop practice,
maybe you can find someone locally that is a machinist, or at least has
some
experience so he/she can guide you. Otherwise, it's best to ask for more
information here. Ask specific questions if you're stumped. There's
way
too much information to dispense to give answers that you have. It
won't
take you long to figure things out with a little guidance from this
group of
people. Many are machinists by trade.

I'm starting to figure out the latter. Actually, I am overdue to visit
the gentleman who taught me the little I know.

Thanks!!!!

Bill

Welcome! Hope some of my ravings help. Do rely on others, especially if
they're skilled. Learning from self taught people can have its own set of
problems, depending on where they got their information. Learning how to
do something stupid from someone that does it that way doesn't make it
right, or good. At first, it might be hard to differentiate those that know
from those that don't, but your experiences will help you sort them out.

Harold