Air Drills

[Mike Rapoport]

I have read that the optimium speed for drilling small holes in thin
aluminium is something on the order of 30k rpm which is well beyond what any
of the drills that I have seen are capable of. There is a 15,000 rpm drill
made by US Industrial availible as well as 4500rpm models. If I get the
15,000 rpm model, will it have enough torque for my needs or will I want a
second air drill (I have numerous electric and cordless drills)? What do
you guys use and recommend? Which drills have the best trigger control? I
will be building a Moose.

Mike
MU-2

[Del Rawlins]

In .net> Mike
Rapoport wrote:
> I have read that the optimium speed for drilling small holes in thin
> aluminium is something on the order of 30k rpm which is well beyond
> what any of the drills that I have seen are capable of. There is a 15,
> 000 rpm drill made by US Industrial availible as well as 4500rpm
> models. If I get the 15,000 rpm model, will it have enough torque for
> my needs or will I want a second air drill (I have numerous electric
> and cordless drills)? What do you guys use and recommend? Which
> drills have the best trigger control? I will be building a Moose.

Sioux makes a 6000rpm model which I own and highly recommend for sheet
metal work.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

[Veeduber]

>I have read that the optimium speed for drilling small holes in thin
>aluminium is something on the order of 30k rpm

----------------------------------------------------

Dear Mike,

That may be true but the key is the definition of 'small' and 'thin.' (30k is
more in the realm of CNC, carbide cutters and so forth. If wer'e talking
rivets the smallest standard size is an AN2 -- 1/16" nominal diameter, in which
case the optimum drill bit rpm is about 6000, usually only obtainable with one
of those special 'needle drills.' (ie, in-line air-drill, generally used for
making the holes for data plates and the like)

AN3's need about 4000rpm, AN4's about 3000.

You can work all this out for yourself. The equation is: SFM / (.2618 x drill
diameter) = RPM.

SFM is 'Surface Feet per Minute;' a constant reflecting the type of material
being drilled. Aluminum is 100, cast iron 70, mild steel 60, alloy steel 40...
it's in all the manuals. (Or usta be :-)

---------------------------------------------------

With your drill-motor running at the proper tool speed (or close to it)
aluminum is virtually transparent to the tool bit -- it takes only an instant
to drill the hole, which comes out nice and round and with square sides because
you haven't stood there pushing on the thing for five minutes, which you DO if
you're using one of those 1200 rpm drills from K-mart or, heaven forbid, that
wunnerful 560 rpm, 12v portable drill from Harbor Freight.

You'll find all this poop and more in the 'RIVETING 101' folder, in the Basic
Sheet Metal folder, in the files archive over on the Fly5kfiles Group. That's
not a real Group, by the way -- nobody swapping stories -- it's just an
overflow archive they opened up after we filled the archival space of the other
common homebuilder Groups (AirVW and Fly5k).

-R.S.Hoover

[Mike Rapoport]

"Veeduber" > wrote in message
...
> >I have read that the optimium speed for drilling small holes in thin
> >aluminium is something on the order of 30k rpm
>
> ----------------------------------------------------
>
> Dear Mike,
>
> That may be true but the key is the definition of 'small' and 'thin.' (30k
is
> more in the realm of CNC, carbide cutters and so forth. If wer'e talking
> rivets the smallest standard size is an AN2 -- 1/16" nominal diameter, in
which
> case the optimum drill bit rpm is about 6000, usually only obtainable with
one
> of those special 'needle drills.' (ie, in-line air-drill, generally used
for
> making the holes for data plates and the like)
>
> AN3's need about 4000rpm, AN4's about 3000.
>
> You can work all this out for yourself. The equation is: SFM / (.2618 x
drill
> diameter) = RPM.
>
> SFM is 'Surface Feet per Minute;' a constant reflecting the type of
material
> being drilled. Aluminum is 100, cast iron 70, mild steel 60, alloy steel
40...
> it's in all the manuals. (Or usta be :-)
>
> ---------------------------------------------------
>
> With your drill-motor running at the proper tool speed (or close to it)
> aluminum is virtually transparent to the tool bit -- it takes only an
instant
> to drill the hole, which comes out nice and round and with square sides
because
> you haven't stood there pushing on the thing for five minutes, which you
DO if
> you're using one of those 1200 rpm drills from K-mart or, heaven forbid,
that
> wunnerful 560 rpm, 12v portable drill from Harbor Freight.
>
> You'll find all this poop and more in the 'RIVETING 101' folder, in the
Basic
> Sheet Metal folder, in the files archive over on the Fly5kfiles Group.
That's
> not a real Group, by the way -- nobody swapping stories -- it's just an
> overflow archive they opened up after we filled the archival space of the
other
> common homebuilder Groups (AirVW and Fly5k).
>
> -R.S.Hoover

Thanks! How do I get to "Fly5kfiles Group"?

Mike

[Aardvark]

Mike Rapoport wrote:

> "Veeduber" > wrote in message
> ...
>
>>>I have read that the optimium speed for drilling small holes in thin
>>>aluminium is something on the order of 30k rpm
>>
>>----------------------------------------------------
>>
>>Dear Mike,
>>
>>That may be true but the key is the definition of 'small' and 'thin.' (30k
>
> is
>
>>more in the realm of CNC, carbide cutters and so forth. If wer'e talking
>>rivets the smallest standard size is an AN2 -- 1/16" nominal diameter, in
>
> which
>
>>case the optimum drill bit rpm is about 6000, usually only obtainable with
>
> one
>
>>of those special 'needle drills.' (ie, in-line air-drill, generally used
>
> for
>
>>making the holes for data plates and the like)
>>
>>AN3's need about 4000rpm, AN4's about 3000.
>>
>>You can work all this out for yourself. The equation is: SFM / (.2618 x
>
> drill
>
>>diameter) = RPM.
>>
>>SFM is 'Surface Feet per Minute;' a constant reflecting the type of
>
> material
>
>>being drilled. Aluminum is 100, cast iron 70, mild steel 60, alloy steel
>
> 40...
>
>>it's in all the manuals. (Or usta be :-)
>>
>>---------------------------------------------------
>>
>>With your drill-motor running at the proper tool speed (or close to it)
>>aluminum is virtually transparent to the tool bit -- it takes only an
>
> instant
>
>>to drill the hole, which comes out nice and round and with square sides
>
> because
>
>>you haven't stood there pushing on the thing for five minutes, which you
>
> DO if
>
>>you're using one of those 1200 rpm drills from K-mart or, heaven forbid,
>
> that
>
>>wunnerful 560 rpm, 12v portable drill from Harbor Freight.
>>
>>You'll find all this poop and more in the 'RIVETING 101' folder, in the
>
> Basic
>
>>Sheet Metal folder, in the files archive over on the Fly5kfiles Group.
>
> That's
>
>>not a real Group, by the way -- nobody swapping stories -- it's just an
>>overflow archive they opened up after we filled the archival space of the
>
> other
>
>>common homebuilder Groups (AirVW and Fly5k).
>>
>>-R.S.Hoover
>
>
> Thanks! How do I get to "Fly5kfiles Group"?
>
> Mike
>
>
http://groups.yahoo.com/group/Fly5kfiles/

WW

[Del Rawlins]

In > Veeduber wrote:

> AN3's need about 4000rpm, AN4's about 3000.
>
> You can work all this out for yourself. The equation is: SFM / (.
> 2618 x drill diameter) = RPM.
>
> SFM is 'Surface Feet per Minute;' a constant reflecting the type of
> material being drilled. Aluminum is 100, cast iron 70, mild steel 60,
> alloy steel 40... it's in all the manuals. (Or usta be :-)

I don't claim to have anything close to your experience, but in A&P
school I was taught to use up to 300fpm for aluminum with hss bits,
depending on the alloy used. Out in the garage I have a copy of a speed
chart which seems to justify this. With a plain carbon steel bit your
numbers make a lot more sense so that is probably their basis, but I
think most builders are probably using hss bits if not something better
like cobalt. I do know that my 6000rpm air drill works slicker than
snot for drilling #30 and #40 holes in aluminum. Drilled around 1500 #
40 holes in my wing ribs last weekend using it. The standard 2700-
2800rpm air drills work OK for aluminum but that is the slowest I would
want to use. I'm thinking of picking up a 3600rpm motor for
countersinking, but that isn't a huge priority just yet.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

[Veeduber]

>in A&P
>school I was taught to use up to 300fpm for aluminum with hss bits,
>depending on the alloy used.

--------------------------------------------------------

Dear Del (and the Group),

I got most of my basic aviation metalsmith training from my uncle Sam between
1956 & 1960. You'll find the figures I've cited in any of the manuals from
that era for any of the services. I happened to be Navy but the basic stuff is
the same in the Air Force manuals (AF Manual 52-11, etc.) which were reprinted
by the EAA.

The figures are for carbon-steel drill bits having an included angle of 90
degrees (ie, standard issue 'aviation' drill bits, at that time) and used dry
(ie, no lubricant).

Drawing from the same sources (ie, military training manuals) you will find 300
SFM listed for lathe & milling operations using HSS bits and cutting fluid.

Other cutting tools (and drill bits) such as 5% Cobolt, carbide or steels
treated with titanium-nitride vapor depostion may be operated at speeds higher
than those listed but their use departs from the issue at hand about which I
think there are three points that need to be made.

The first point is that the typical homebuilder has no idea in the blue-eyed
world as to the relationship between tool-speed and producing an accurately
drilled hole. They are using tools inappropriate to the task and no one
bothers to explain why their eighth-inch drill bit turning only 1200rpm in
their K-mart 1/4" drill-motor keeps skittering across the surface, other than
to tell them they need an air-drill.

Secondly, offering them an equation or a printed table that links rpm to drill
diameter should give them some idea that the two are related, especially if
some stress is placed on the fact that skinny drills must spin faster than
fatter drills. The hope here is they'll pick up the idea that they are dealing
with a CUTTING TOOL rather than some kind of rotary punch, where
one-speed-suits-all and you simply have to PUSH HARDER when making a bigger
hole.

The third point has to do with the Conventional Wisdomites who, having learned
that Faster is Better, run around repeating the highest number they've heard
with regard to drilling, confusing airplanes with dentistry. (If 3000 rpm is
good then 30,000 rpm must be GREAT, right?)

The truth is, most homebuilders are using dull drills, having the wrong angle,
chucked into a K-Mart Blue-Light special turning maybe 1200rpm. I've no idea
if they are using plain carbon steel or nitrided cobalt -- and neither do they.
But I do know that if they are making bad holes the SFM formula I cited will
PROBABLY help them make better ones.

As for the rest of it, as in who has the biggest SFM equation or the longest
drill -- it's difficult to address the matter in a cogent fashion without
getting into the specifics of alloy, temper, drill-type production rate and so
forth. Fortunately, I don't think we have to. The SFM equation I cited may be
the lowest common denominator when it comes to riveting but it will at least
allow the builder to produce good holes, usually with better accuracy and less
effort than they're presently getting with their 1100 rpm Makita and a packet
of 1/8" double-enders from Harbor Freight. There's nothing in the rules that
sez you can't ADD to that by offering other equations specific to particular
alloys or drill bits.

-R.S.Hoover

[acepilot]

I love my Sioux drill. Great trigger. Mine only goes 2600 RPM. Seems
to do just fine at that speed.

Scott
RV-4 project


Mike Rapoport wrote:

> I have read that the optimium speed for drilling small holes in thin
> aluminium is something on the order of 30k rpm which is well beyond what any
> of the drills that I have seen are capable of. There is a 15,000 rpm drill
> made by US Industrial availible as well as 4500rpm models. If I get the
> 15,000 rpm model, will it have enough torque for my needs or will I want a
> second air drill (I have numerous electric and cordless drills)? What do
> you guys use and recommend? Which drills have the best trigger control? I
> will be building a Moose.
>
> Mike
> MU-2
>
>

[Veeduber]

>I love my Sioux drill. Great trigger. Mine only goes 2600 RPM. Seems
>to do just fine at that speed.

-------------------------------------------------

Dear Scott,

I don' t want to bust up your romance but I suggest you borrow a drill-motor
that turns at a higher speed and shoot a few holes. You really don't know what
you're missing.

I usta have a B&D 'aviation' drill motor, turned something like 4000 rpm. Wore
it out. Had it rebuilt. Twenty years later it needed another rebuild but the
bull-gear was not available at a price I could afford. Since then I've been
using those cheap Chinee imports that turn 3600 rpm, last just about long
enough for one airplane's-worth of holes, throw it away when it gets noisy.
Air tools are nice but compressing air to drive a drill puts you on the wrong
side of the economic equation here in southern California.

That's a point a lot of newbies miss. Pneumatic drill is a real air hog; takes
a pretty good compresser to keep you working. (On the other hand, pneumatic
riveting hammers or squeezers don't use much air.) If a guy doesn't already
have a big compressor, when you add the acquisition cost to the operating cost
and divide by the number of holes, it represents a significant increase in cost
when compared to using throw-away electric drill motors.

-R.S.Hoover

[Blueskies]

What drill motors do you recommend?

--
Dan D.



..
"Veeduber" > wrote in message ...
> >I love my Sioux drill. Great trigger. Mine only goes 2600 RPM. Seems
> >to do just fine at that speed.
>
> -------------------------------------------------
>
> Dear Scott,
>
> I don' t want to bust up your romance but I suggest you borrow a drill-motor
> that turns at a higher speed and shoot a few holes. You really don't know what
> you're missing.
>
> I usta have a B&D 'aviation' drill motor, turned something like 4000 rpm. Wore
> it out. Had it rebuilt. Twenty years later it needed another rebuild but the
> bull-gear was not available at a price I could afford. Since then I've been
> using those cheap Chinee imports that turn 3600 rpm, last just about long
> enough for one airplane's-worth of holes, throw it away when it gets noisy.
> Air tools are nice but compressing air to drive a drill puts you on the wrong
> side of the economic equation here in southern California.
>
> That's a point a lot of newbies miss. Pneumatic drill is a real air hog; takes
> a pretty good compresser to keep you working. (On the other hand, pneumatic
> riveting hammers or squeezers don't use much air.) If a guy doesn't already
> have a big compressor, when you add the acquisition cost to the operating cost
> and divide by the number of holes, it represents a significant increase in cost
> when compared to using throw-away electric drill motors.
>
> -R.S.Hoover

[Del Rawlins]

In > Veeduber wrote:

> The truth is, most homebuilders are using dull drills, having the
> wrong angle, chucked into a K-Mart Blue-Light special turning maybe
> 1200rpm. I've no idea if they are using plain carbon steel or
> nitrided cobalt -- and neither do they. But I do know that if they
> are making bad holes the SFM formula I cited will PROBABLY help them
> make better ones.

I guess I just associate with a higher class of homebuilders over on the
Bearhawk list. 8^) We don't typically get into drill speed formulas
but for the most part we all use decent tools. Then again, there are
enough holes to drill in the BH wing that using the K-mart special would
almost certainly drive the user completely insane in short order.

----------------------------------------------------
Del Rawlins-
Remove _kills_spammers_ to reply via email.
Unofficial Bearhawk FAQ website:
http://www.rawlinsbrothers.org/bhfaq/

[B.H. Lazard]

"Blueskies" > wrote in message
.com...
> What drill motors do you recommend?

He does not recommend any. He just wants everyone to know they do not know
****.



> --
> Dan D.
>
>
>
> .
> "Veeduber" > wrote in message
...

[Morgans]

"B.H. Lazard" > wrote >
> He does not recommend any. He just wants everyone to know they do not know
> ****.

You are real off on that comment. He is one of the most worthwhile reads on
RAH.

I think you need to stick around for a while, before you snap to such
judgements.

For now, PLONK.
--
Jim in NC


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
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[Veeduber]

>What drill motors do you recommend?

----------------------------------------------------------

Dear Dan,

If you mean 'recommend' in the sense of endorsement, I don't. I don't have
enough experience with the stuff that's presently available. To offer an
opinion that isn't based on actual experience is little more than a lie. Most
of my tools are like me: Old. Most were inhereted or purchased used,
subsidized by WWII and most came from companies that no longer exist.

To drill a clean hole the motor must be capable of spinning the bit at the
proper speed. The chuck has spin reasonably true and the thing should be
durable enough to not break down half-way through the job. But a high
percentage of the mail I get is from guys building on a very tight budget, far
removed from the typical kit assembler. That puts me in something of a bind
with regard to recommending tools because I know a cheap tool is no bargain...
even through their use may be a NECESSITY for some builders.

In the past I've mentioned a high-speed 1/4" drill motor available from Harbor
Freight as being suitable. I did that after buying one and using it for a few
hundred holes. Of course, by the time I mentioned it, that particular
item-number was no longer available and we had to wait for the next boat from
China :-)

These aren't what I consider durable tools, although most will give you at
least one airplane's-worth of service. But if you're doing repair work or
bucking rivets at one of the local RV factories, their price is so low that if
you wait for a sale it makes good sense to buy a batch of them and simply use
the things up.

See if you can find the riveting article I wrote. Or the one on drilling ('The
Hole Story'). They may broaden your perspective on this task. Truth is, you
can use a manually-powered hand-drill if that's all you got (they made special
'high speed' hand-drills just for aircraft work) but there's a bit more to it
than simply turning the crank. Same is true when using an electric or
pneumatic drill-motor. ANY of them can save you some time but some are much
more appropriate for aviation metalsmithing than others.

-R.S.Hoover

[Blueskies]

Thanks, I was wondering what electric motor type is around. I have seen quite a few air drills for a reasonable cost
with the speed we need, but as stated earlier you need a good hi-flow compressor which I don't have. Hmmmm...

--
Dan D.



..
"Veeduber" > wrote in message ...
> >What drill motors do you recommend?
>
> ----------------------------------------------------------
>
> Dear Dan,
>
> If you mean 'recommend' in the sense of endorsement, I don't. I don't have
> enough experience with the stuff that's presently available. To offer an
> opinion that isn't based on actual experience is little more than a lie. Most
> of my tools are like me: Old. Most were inhereted or purchased used,
> subsidized by WWII and most came from companies that no longer exist.
>
> To drill a clean hole the motor must be capable of spinning the bit at the
> proper speed. The chuck has spin reasonably true and the thing should be
> durable enough to not break down half-way through the job. But a high
> percentage of the mail I get is from guys building on a very tight budget, far
> removed from the typical kit assembler. That puts me in something of a bind
> with regard to recommending tools because I know a cheap tool is no bargain...
> even through their use may be a NECESSITY for some builders.
>
> In the past I've mentioned a high-speed 1/4" drill motor available from Harbor
> Freight as being suitable. I did that after buying one and using it for a few
> hundred holes. Of course, by the time I mentioned it, that particular
> item-number was no longer available and we had to wait for the next boat from
> China :-)
>
> These aren't what I consider durable tools, although most will give you at
> least one airplane's-worth of service. But if you're doing repair work or
> bucking rivets at one of the local RV factories, their price is so low that if
> you wait for a sale it makes good sense to buy a batch of them and simply use
> the things up.
>
> See if you can find the riveting article I wrote. Or the one on drilling ('The
> Hole Story'). They may broaden your perspective on this task. Truth is, you
> can use a manually-powered hand-drill if that's all you got (they made special
> 'high speed' hand-drills just for aircraft work) but there's a bit more to it
> than simply turning the crank. Same is true when using an electric or
> pneumatic drill-motor. ANY of them can save you some time but some are much
> more appropriate for aviation metalsmithing than others.
>
> -R.S.Hoover

[Bushy]

> you need a good hi-flow compressor which I don't have.

I bought a cheap compressor so I could take it out to customer jobsites and
it would fit in the back of my wagon. The $99.00 GMC one from Bunnings, the
Australian hardware chain store. It works pretty well, but only has low
recharging flow from it's 1500 watt motor and a small 24 litre tank.

To improve it, I added a second one and hooked the two together with a
simple hose, WOW, it really roars now and will keep up to even my spray gun
happily for ages. They both have two outlets, one regulated and one straight
out of the tank and this is where I connected the hose. The two motors cut
in within a couple of pounds of each other and apart from wanting it to be a
bit quieter, it's more compressor than most of the $500.00 ones I've used.

Hope this helps,
Peter

[CW9371]

>He does not recommend any. He just wants everyone to know they do not know
>****.
>

Hmmm u bash someone but u cant sign it.
chris

[acepilot]

I have a 60 gallon upright air compressor and it seems to run the air
drill fine. I've never seen an electric drill that turned RPMs in the
thousands. My Makita cordless at work might do a few HUNDRED RPM. When
I bought my Sioux, it was the highest speed air drill I found at an
aviation tool supply. Oh well, that's life...

Scott


Veeduber wrote:
>>I love my Sioux drill. Great trigger. Mine only goes 2600 RPM. Seems
>>to do just fine at that speed.
>
>
> -------------------------------------------------
>
> Dear Scott,
>
> I don' t want to bust up your romance but I suggest you borrow a drill-motor
> that turns at a higher speed and shoot a few holes. You really don't know what
> you're missing.
>
> I usta have a B&D 'aviation' drill motor, turned something like 4000 rpm. Wore
> it out. Had it rebuilt. Twenty years later it needed another rebuild but the
> bull-gear was not available at a price I could afford. Since then I've been
> using those cheap Chinee imports that turn 3600 rpm, last just about long
> enough for one airplane's-worth of holes, throw it away when it gets noisy.
> Air tools are nice but compressing air to drive a drill puts you on the wrong
> side of the economic equation here in southern California.
>
> That's a point a lot of newbies miss. Pneumatic drill is a real air hog; takes
> a pretty good compresser to keep you working. (On the other hand, pneumatic
> riveting hammers or squeezers don't use much air.) If a guy doesn't already
> have a big compressor, when you add the acquisition cost to the operating cost
> and divide by the number of holes, it represents a significant increase in cost
> when compared to using throw-away electric drill motors.
>
> -R.S.Hoover

[Blueskies]

A Dremel turns fast enough, but I don't think it has the oomph...

--
Dan D.



..
"acepilot" > wrote in message ...
> I have a 60 gallon upright air compressor and it seems to run the air
> drill fine. I've never seen an electric drill that turned RPMs in the
> thousands. My Makita cordless at work might do a few HUNDRED RPM. When
> I bought my Sioux, it was the highest speed air drill I found at an
> aviation tool supply. Oh well, that's life...
>
> Scott
>
>
> Veeduber wrote:
> >>I love my Sioux drill. Great trigger. Mine only goes 2600 RPM. Seems
> >>to do just fine at that speed.
> >
> >
> > -------------------------------------------------
> >
> > Dear Scott,
> >
> > I don' t want to bust up your romance but I suggest you borrow a drill-motor
> > that turns at a higher speed and shoot a few holes. You really don't know what
> > you're missing.
> >
> > I usta have a B&D 'aviation' drill motor, turned something like 4000 rpm. Wore
> > it out. Had it rebuilt. Twenty years later it needed another rebuild but the
> > bull-gear was not available at a price I could afford. Since then I've been
> > using those cheap Chinee imports that turn 3600 rpm, last just about long
> > enough for one airplane's-worth of holes, throw it away when it gets noisy.
> > Air tools are nice but compressing air to drive a drill puts you on the wrong
> > side of the economic equation here in southern California.
> >
> > That's a point a lot of newbies miss. Pneumatic drill is a real air hog; takes
> > a pretty good compresser to keep you working. (On the other hand, pneumatic
> > riveting hammers or squeezers don't use much air.) If a guy doesn't already
> > have a big compressor, when you add the acquisition cost to the operating cost
> > and divide by the number of holes, it represents a significant increase in cost
> > when compared to using throw-away electric drill motors.
> >
> > -R.S.Hoover
>

[Dan Thomas]

acepilot > wrote in message >...
> I have a 60 gallon upright air compressor and it seems to run the air
> drill fine. I've never seen an electric drill that turned RPMs in the
> thousands. My Makita cordless at work might do a few HUNDRED RPM. When
> I bought my Sioux, it was the highest speed air drill I found at an
> aviation tool supply. Oh well, that's life...
>
> Scott

I have an ancient direct-drive air drill I found at a Princess
Auto here in Canada. No gears in it, and it turns at some insane speed
like an air die-grinder, maybe 15 or 20,000 RPM. It sure does a nice
job on small holes in aluminum, very little tendency to skid.
I wonder if it might be worthwhile to make a threaded adapter for a
1/4" chuck and clamp it into the collet of a 90-degree die grinder? Or
are there any pistol-grip die grinders?

Dan

[ken]

Actually there is a 3/32, 1/8, 1/4? set of collets available from
Princess Auto that seem to work fine with #30 and #40 bits in their
cheap 90 degree die grinder. It gets into tighter places that way than
it could with a chuck. I find that it turns too fast though and needs a
steady hand or it will cut sideways like a router ;( It will make a
hole real quick though if you don't have anything else that can get
access to where you are working ;)
Ken

> I have an ancient direct-drive air drill I found at a Princess
> Auto here in Canada. No gears in it, and it turns at some insane speed
> like an air die-grinder, maybe 15 or 20,000 RPM. It sure does a nice
> job on small holes in aluminum, very little tendency to skid.
> I wonder if it might be worthwhile to make a threaded adapter for a
> 1/4" chuck and clamp it into the collet of a 90-degree die grinder? Or
> are there any pistol-grip die grinders?
>
> Dan

[Model Flyer]

"acepilot" > wrote in message
...
> I have a 60 gallon upright air compressor and it seems to run the
air
> drill fine. I've never seen an electric drill that turned RPMs in
the
> thousands.

I have an electric drill that runs at 3000, great for drilling 1/8
but not that good for under that size. It's home made, used the motor
out of a B&D lawnmower, it used the same caseing as one of the small
B&D's but with a higher gear ratio.
--
---
Cheers,
Jonathan Lowe.
/
don't bother me with insignificiant nonsence such as spelling,
I don't care if it spelt properly
/
Sometimes I fly and sometimes I just dream about it.
:-)


> My Makita cordless at work might do a few HUNDRED RPM. When




> I bought my Sioux, it was the highest speed air drill I found at an
> aviation tool supply. Oh well, that's life...
>
> Scott
>
>
> Veeduber wrote:
> >>I love my Sioux drill. Great trigger. Mine only goes 2600 RPM.
Seems
> >>to do just fine at that speed.
> >
> >
> > -------------------------------------------------
> >
> > Dear Scott,
> >
> > I don' t want to bust up your romance but I suggest you borrow a
drill-motor
> > that turns at a higher speed and shoot a few holes. You really
don't know what
> > you're missing.
> >
> > I usta have a B&D 'aviation' drill motor, turned something like
4000 rpm. Wore
> > it out. Had it rebuilt. Twenty years later it needed another
rebuild but the
> > bull-gear was not available at a price I could afford. Since
then I've been
> > using those cheap Chinee imports that turn 3600 rpm, last just
about long
> > enough for one airplane's-worth of holes, throw it away when it
gets noisy.
> > Air tools are nice but compressing air to drive a drill puts you
on the wrong
> > side of the economic equation here in southern California.
> >
> > That's a point a lot of newbies miss. Pneumatic drill is a real
air hog; takes
> > a pretty good compresser to keep you working. (On the other
hand, pneumatic
> > riveting hammers or squeezers don't use much air.) If a guy
doesn't already
> > have a big compressor, when you add the acquisition cost to the
operating cost
> > and divide by the number of holes, it represents a significant
increase in cost
> > when compared to using throw-away electric drill motors.
> >
> > -R.S.Hoover
>

[Roger Halstead]

On Sun, 7 Mar 2004 00:18:18 -0000, "Model Flyer" >
wrote:

>
>"acepilot" > wrote in message
...
>> I have a 60 gallon upright air compressor and it seems to run the
>air
>> drill fine. I've never seen an electric drill that turned RPMs in
>the
>> thousands.
>
>I have an electric drill that runs at 3000, great for drilling 1/8
>but not that good for under that size. It's home made, used the motor

Why would you want to run a drill bit that fast?

I normally use less than half that speed even for the tiny ones.
Although I have a number of air tools, I learned to hate that sound
after working on an assembly line in my younger days.


Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
>out of a B&D lawnmower, it used the same caseing as one of the small
>B&D's but with a higher gear ratio.

[Del Rawlins]

In > Roger Halstead wrote:
> On Sun, 7 Mar 2004 00:18:18 -0000, "Model Flyer" >
> wrote:
>
>>I have an electric drill that runs at 3000, great for drilling 1/8
>>but not that good for under that size. It's home made, used the motor
>
> Why would you want to run a drill bit that fast?
>
> I normally use less than half that speed even for the tiny ones.
> Although I have a number of air tools, I learned to hate that sound
> after working on an assembly line in my younger days.

Because they work better at the higher speeds.

----------------------------------------------------
Del Rawlins-
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