"Jon Elson" wrote in message
rvers.com...
Jim B wrote:
Although I'm a novice to metalworking I recently decided to build a
project out of aluminum and bought a set of inexpensive adjustable
reamers when I found that I couldn't drill a hole accurate enough for
my needs.

I've never used one of these reamers or even seen someone else use one.
I found some good information and instruction in this group and
elsewhere on the net but I've been unable to find the answer to one
very basic question - Which way do you turn the reamer? Clockwise or
counter-clockwise.

What little I've found concerns chucking reamers and seems to indicate
that they turn in a clockwise direction. When I try this with the hand
reamer it chews into the work and I can't keep it straight.

On the other hand, if I turn it counter-clockwise, it stays straight
but it's very slow and I have to use alot of downward pressure on it to
get it to work. If I was working with steel I don't know if it would
work at all.

I guess counter-clockwise is correct but I'd sure like someone that
knows to confirm this for me.
No, clockwise, if you are standing behins the drill motor, looking at
the hole. But, you are probably taking too much material off in one
pass. Normally, you want to take off .007" on the diameter, at the
most, in one pass. If you take off too much material, you get tearing
instead of smooth cutting of a very thin shaving off the ID of the hole.
This can be a problem if the hole came out rough or not straight.

Also, these reamers are really best used in a drill press or milling
machine, so the spindle can keep the reamer straight. These machines
also make it easy to keep a steady slow infeed on the reamer. it is a
LOT harder to do this freehand with an electric drill, which you may
be trying to do.

It is not clear what you mean by drilling a hole accurate enough. A
reamer won't improve hole location, it will follow the existing hole.
If your problem is diameter, roundness or straightness, then the reamer
can clearly help.

Jon


Jon,
I get the idea he's talking about *hand reamers*, which do not respond well
to being machine driven. In the hands of a novice, it would surely spell
disaster.

Jim:

I can't help but think that you're talking about hand reamers (they have a
square drive, and are tapered). If so, you'd be well served to use them in
a drill press or mill, piece clamped in correct position under the chuck,
with a center following the hand reamer while it's being turned with an
adjustable wrench or T handle of sorts, manually, not under machine power.
Do *NOT* use an adjustable wrench if you don't have a center following the
reamer, keeping it in line and preventing tipping. Lubricate well with
kerosene, or a good tapping solution for aluminum. A light cut is
preferred. Don't try to take much out of the hole with the pass. Turn the
reamer(s) clockwise, as you stand behind the reamer. Turning it counter
clockwise will ruin the teeth, especially in steel. Could be even
aluminum has dulled it by turning it backwards. Look at the teeth where
they contact the work. If they have a tiny, shiny radius instead of a sharp
edge, the reamer(s) won't cut worth a damn. The edge is already gone. They
must be sharpened with a cutter grinder, they can't be done by hand.

Harold