"MinorMania" wrote in message
...
Hi All

I need to enlarge the mounting holes in a set of cast aluminium wheels
from
5/8 to 17.5mm. I have a new reduced shank drill that I am using in an air
drill (hand held) as I don't want to demount the tyres.

I'm finding the drill is grabbing quite badly in the soft aluminium. I
found
in a search that you can 'stone' the drill to stop this happening, or at
least make it better. I'm curious about which part of the drill should get
this treatment though. The cutting lips, or ???

Thanks, Trev.

My machinist's supply suggested doing that to the cutting lips on a new
2-3/8" drill bit we bought. The operation we were doing was in a drill press
and the workpiece was clamped. It still cut fine, not sure exactly how much
it grabbed, though.

"MinorMania" wrote in message
...
Hi All

I need to enlarge the mounting holes in a set of cast aluminium wheels
from
5/8 to 17.5mm. I have a new reduced shank drill that I am using in an air
drill (hand held) as I don't want to demount the tyres.

I'm finding the drill is grabbing quite badly in the soft aluminium. I
found
in a search that you can 'stone' the drill to stop this happening, or at
least make it better. I'm curious about which part of the drill should get
this treatment though. The cutting lips, or ???

Thanks, Trev.


The cutting face, or flute, which forms the cutting edge rake angle, is what
should be stoned. Stoning the edge to reduce the angle will reduce the
inclination to hog. If you're confused what should be stoned, you'd be
better off to seek assistance so you don't end up screwing up the drill. If
you feel you understand, don't go negative, and try to keep the alteration
of each side the same. You might have better luck with a wheel instead of
a stone, assuming you have good hand grinding skills.

It likely goes without saying that this job would be far better done under
controlled conditions (not by hand) to insure you don't wallow out the
holes, nor lose relative position. That being said, it can be done by
hand, it just offers more risks, as you've discovered.

Harold

"MinorMania" wrote in message
...
| Hi All
|
| I need to enlarge the mounting holes in a set of cast aluminium wheels
from
| 5/8 to 17.5mm. I have a new reduced shank drill that I am using in an air
| drill (hand held) as I don't want to demount the tyres.
|
| I'm finding the drill is grabbing quite badly in the soft aluminium. I
found
| in a search that you can 'stone' the drill to stop this happening, or at
| least make it better. I'm curious about which part of the drill should get
| this treatment though. The cutting lips, or ???
|
| Thanks, Trev.

First off, put some lube in there. Secondly, don't push. Keep a firm
grip on the drill so that it doesn't want to get ahead of you or away. Spin
it up fast before you enter the hole and don't push when it's in a spot
where it wants to bind up. Let the drill bit clip off the burr that comes
from getting too big a bite then go in easy.
If you can step up in size to where you want to be you'll get a good
clean hole with less binding as will happen from a single drill bit.

That's a pretty big hole to try and drill by hand because you are
feeling the torque caused by those tips as they cut the aluminum. Unless
you have 19" biceps and press 500 pounds, I doubt the result will be
very pretty. As for "stoning" the bit, IMO that sounds like advice from
someone who spends a lot of time stoned. Without some experience,
anything you do to the modify bit is likely to make it worse not better.

Forget the air drill. Take the wheels off and drill them on a drill
press with plenty of lube and some clamps.


MinorMania wrote:

Hi All

I need to enlarge the mounting holes in a set of cast aluminium wheels from
5/8 to 17.5mm. I have a new reduced shank drill that I am using in an air
drill (hand held) as I don't want to demount the tyres.

I'm finding the drill is grabbing quite badly in the soft aluminium. I found
in a search that you can 'stone' the drill to stop this happening, or at
least make it better. I'm curious about which part of the drill should get
this treatment though. The cutting lips, or ???

Thanks, Trev.

Stop!

Perhaps you should consider your options. If each wheel has 5 lug holes and
you bugger one up how much has this exercise in frugality cost you? Or
worse, consider if you have wheels that are buggered and you get into a
wreck?

Take the stinking wheels to a machine shop and let them drill out your
holes.

--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.


"MinorMania" wrote in message
...
Hi All

I need to enlarge the mounting holes in a set of cast aluminium wheels
from
5/8 to 17.5mm. I have a new reduced shank drill that I am using in an air
drill (hand held) as I don't want to demount the tyres.

I'm finding the drill is grabbing quite badly in the soft aluminium. I
found
in a search that you can 'stone' the drill to stop this happening, or at
least make it better. I'm curious about which part of the drill should get
this treatment though. The cutting lips, or ???

Thanks, Trev.

"Harold and Susan Vordos" wrote in message
...

"MinorMania" wrote in message
...
Hi All

I need to enlarge the mounting holes in a set of cast aluminium wheels
from
5/8 to 17.5mm. I have a new reduced shank drill that I am using in an
air
drill (hand held) as I don't want to demount the tyres.

I'm finding the drill is grabbing quite badly in the soft aluminium. I
found
in a search that you can 'stone' the drill to stop this happening, or at
least make it better. I'm curious about which part of the drill should
get
this treatment though. The cutting lips, or ???

Thanks, Trev.


The cutting face, or flute, which forms the cutting edge rake angle, is
what
should be stoned. Stoning the edge to reduce the angle will reduce the
inclination to hog. If you're confused what should be stoned, you'd be
better off to seek assistance so you don't end up screwing up the drill.
If
you feel you understand, don't go negative, and try to keep the alteration
of each side the same. You might have better luck with a wheel instead
of
a stone, assuming you have good hand grinding skills.

It likely goes without saying that this job would be far better done under
controlled conditions (not by hand) to insure you don't wallow out the
holes, nor lose relative position. That being said, it can be done by
hand, it just offers more risks, as you've discovered.


http://yarchive.net/metal/brass_drilling.html

--

SVL

In article ,
"MinorMania" wrote:

Hi All

I need to enlarge the mounting holes in a set of cast aluminium wheels from
5/8 to 17.5mm. I have a new reduced shank drill that I am using in an air
drill (hand held) as I don't want to demount the tyres.

I'm finding the drill is grabbing quite badly in the soft aluminium. I found
in a search that you can 'stone' the drill to stop this happening, or at
least make it better. I'm curious about which part of the drill should get
this treatment though. The cutting lips, or ???

About the only way I would attempt this with a hand drill is to make a
special bit with a 5/8" pilot and one cutting lip like a unibit. Also I
would think an air drill is too fast, an electric might be better.

--
Free men own guns, slaves don't
www.geocities.com/CapitolHill/5357/

....

http://yarchive.net/metal/brass_drilling.html


What a wonderful walk down memory lane. Went "up" to index and seen lots of
posts by "Teenut", Robert Bastow. May he rest in piece. I didn't see my
personal favorite "Teenut" post, the six million dollar bionic drill
sharpener, or how to hand sharpen a drill bit.

Karl

Dare I suggest using an expandable hand reamer? It will do a neat job
without the risk of 'bellmouthing' the holes.
Bugs

"Karl Townsend" remove .NOT to reply wrote
in message ink.net...

...

http://yarchive.net/metal/brass_drilling.html


What a wonderful walk down memory lane. Went "up" to index and seen lots
of
posts by "Teenut", Robert Bastow. May he rest in piece. I didn't see my
personal favorite "Teenut" post, the six million dollar bionic drill
sharpener, or how to hand sharpen a drill bit.


I didnt read it all-standard drill modification for drilling brass applies
in this kind of case is all.

When your hand drilling to enlarge a hole only a tad bit then your positive
rake due to the flute helix is mostly a hindrance...better method would be
to use a straight shank reamer or core drill.

--

SVL

The "stoning" is to reduce the angle of the tip of the drill so that when it
grabs (and it WILL) it won't screw itself so far into the hole that you
can't get it out easily. You also want to stone the edge off of the sides
past about the first tenth of an inch of the flutes so that they won't grab
in the bore.
It would be a lot better to put the wheel in a drillpress or, better yet, a
mill to do the drilling as you will be keeping the drill bit straight and
can control the cutting rate a lot better. Also, you can use a lower speed
which will help control things a lot better than a bouncy air drill which
will kick sideways as the drill bit sinks into the metal.
Considering the amount of material that you need to remove, you might also
want to consider using a reamer instead for this job as you're taking less
than 1mm of material off the wall of the hole.

--
Why isn't there an Ozone Hole at the NORTH Pole?

Hi All

I need to enlarge the mounting holes in a set of cast aluminium wheels from
5/8 to 17.5mm. I have a new reduced shank drill that I am using in an air
drill (hand held) as I don't want to demount the tyres.

I'm finding the drill is grabbing quite badly in the soft aluminium. I found
in a search that you can 'stone' the drill to stop this happening, or at
least make it better. I'm curious about which part of the drill should get
this treatment though. The cutting lips, or ???

Thanks, Trev.

I need to enlarge the mounting holes in a set of cast aluminium wheels
from
5/8 to 17.5mm. I have a new reduced shank drill that I am using in an air
drill (hand held) as I don't want to demount the tyres.

It sounds like might be trying to adapt a set a wheels to a different hub
type. Be careful here, the center hole of the wheel is what locates it
accurately on the hub, not the wheel studs, they just clamp the wheel to the
hub. You need to make sure that the hub center is the same diameter on both
the new hub and the old hub or these wheels will shake and vibrate and
eventually come off.

Paul T.

"PrecisionMachinisT" wrote in message
...

When your hand drilling to enlarge a hole only a tad bit then your
positive
rake due to the flute helix is mostly a hindrance...better method would be
to use a straight shank reamer or core drill.


Correction, I had meant to say "straight flute"...not "straight shank"...

--

SVL