air drill question

Thanks for posts. Just starting out . Have some manuals but none with
this information. What would be the gold standard of reference manuals
for this information. Had wanted to buy a drill for mostly #30 and 40
drill bits but was at a loss with all the rpm ranges. Sounds like for
aluminum I should be looking at a higher rpm range than I originally
thought.
I had thought this group was amoung other things to use members as a
resource. I suppose I shouldn't be suprised that someone should
criticize me for asking what to some might be obvious, but I don't
think this is a community that eats its young. I might need some more
help in the future. KM

..
"Ded Dog" wrote in message om...
Thanks for posts. Just starting out . Have some manuals but none with
this information. What would be the gold standard of reference manuals
for this information. Had wanted to buy a drill for mostly #30 and 40
drill bits but was at a loss with all the rpm ranges. Sounds like for
aluminum I should be looking at a higher rpm range than I originally
thought.
I had thought this group was amoung other things to use members as a
resource. I suppose I shouldn't be suprised that someone should
criticize me for asking what to some might be obvious, but I don't
think this is a community that eats its young. I might need some more
help in the future. KM

They don't seem to eat the young, they just chew on them for a while....

On 21 Nov 2003 03:04 PM, Ded Dog posted the following:
Thanks for posts. Just starting out . Have some manuals but none with
this information. What would be the gold standard of reference manuals
for this information. Had wanted to buy a drill for mostly #30 and 40
drill bits but was at a loss with all the rpm ranges. Sounds like for
aluminum I should be looking at a higher rpm range than I originally
thought.
I had thought this group was amoung other things to use members as a
resource. I suppose I shouldn't be suprised that someone should
criticize me for asking what to some might be obvious, but I don't
think this is a community that eats its young. I might need some more
help in the future. KM

A brief Google search came up with the following info related to drill
speeds:

http://www.micoks.net/~dbennett/dpsc.html
A Palm application

http://www.collinsclubs.com/woodwork...speedchart.pdf
A PDF chart, not totally useful since it only goes as high as 3000 rpm (
meant for drill presses)

http://www.auto-ware.com/techref/drillspeed.htm
A simple chart which only has fractional sizes by sixteenths.

http://209.92.149.105/keo/faq.asp
Scroll down to the bottom for information which will allow you to
calculate RPM and feed rates for amy material and any bit size.

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

"Ded Dog" wrote in message
I don't think this is a community that eats its young. I might need
some more help in the future. KM

Eat its young? Heavens no! That would imply some finality... around here the
fun just keeps going and going and going! =D

Eric

I don't know which project you are working on, is there a group on line
like wise interested? If so that would probably be an excellent resoure to
take advantage or.

"Morgans" wrote:

There is a wealth of knowledge here, and even more people who don't know
jack, who purport that they do.
+++++++++++++++++++++++++++++++++++++++

No problem.

It's all here....
http://home.pacbell.net/diana_do/knowjack.htm



Barnyard BOb -- knows his Schitt

"Ded Dog" wrote in message
om...
Thanks for posts. Just starting out . Have some manuals but none with
this information. What would be the gold standard of reference manuals
for this information. Had wanted to buy a drill for mostly #30 and 40
drill bits but was at a loss with all the rpm ranges. Sounds like for
aluminum I should be looking at a higher rpm range than I originally
thought.
I had thought this group was amoung other things to use members as a
resource. I suppose I shouldn't be suprised that someone should
criticize me for asking what to some might be obvious, but I don't
think this is a community that eats its young. I might need some more
help in the future. KM

Get a thick skin, if you want to stick around here. We do eat our young
sometimes, and almost always eat newcomers. :-)

There is a wealth of knowledge here, and even more people who don't know
jack, who purport that they do. The trick is telling them apart.

The best things to do, are to get some good books, and read them. Others
are better at giving these lists than me. Also get with an EAA tec adviser,
and get together often.
--
Jim in NC

On 20 Nov 2003 20:47:30 GMT, (Lpmcatee356)
wrote:


Wow. I'm glad I just started reading this group. What a helpful bunch here!
I'll the the original poster would never have thought about looking it up.

Not everything that you and I might take for granted is common knowledge among
some of the new builders - or even somewhat experienced ones. And sometimes
those of us that have been doing "it" for a score+ years forget that not
everybody knows the basics.

To answer the original post - the smaller the drill bit the faster you
can/should turn it.

In my experience:

for sheet metal work (drilling #30 holes) the fastest air drill you can buy is
none too fast.

A sharp split point bit and an accurate center-punch help too.

our experiences differ.
my experience is that most drills spin too fast, particualrly for
aluminium.
the speed of your average cordless battery drill is about right and
allows far better control for freehand drilling.
Stealth Pilot

On 23 Nov 2003 04:26 AM, Stealth Pilot posted the following:
On 20 Nov 2003 20:47:30 GMT, (Lpmcatee356)
wrote:


Wow. I'm glad I just started reading this group. What a helpful bunch
here! I'll the the original poster would never have thought about
looking it up.

Not everything that you and I might take for granted is common
knowledge among some of the new builders - or even somewhat
experienced ones. And sometimes those of us that have been doing "it"
for a score+ years forget that not everybody knows the basics. To
answer the original post - the smaller the drill bit the faster you
can/should turn it.
In my experience:

for sheet metal work (drilling #30 holes) the fastest air drill you
can buy is none too fast. A sharp split point bit and an accurate
center-punch help too.

our experiences differ.
my experience is that most drills spin too fast, particualrly for
aluminium.
the speed of your average cordless battery drill is about right and
allows far better control for freehand drilling.
Stealth Pilot

I agree with the other guy, the faster the better. I don't see how
using a heavy electric drill with a heavy attached battery makes it
easier to control. My Sioux with a lightweight air hose is much easier
to work with than any cordless I have tried, for rivet hole sizes,
anyway. If I'm going to be using my unibit or a larger twist drill I
agree that an electric might be easier to work with.

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

(Ded Dog) wrote:

what rpm range best for aluminum sheet metal? 2600? 3600? less? more?
thanks KM

Let's widen the scope to include other materials.

RPM = 3.8*CS/Dia

where CS is the cutting speed in ft/min and Dia is drill diameter in
inches.

Page 8 of this Cooper Power Tools catalog http://tinyurl.com/w8wi (a
pdf file) lists recommended cutting speeds for various materials.
There is also an RPM table based on those cutting speeds for high
speed drill bits from 1/16 to 3/4 inch. Here are the recommended
cutting speeds,

Material Cutting Speed (ft/min)

Stainless Steel 30-40
Forged Steel 40-50
High Nickel Steel or Monel 40-50
Titanium Alloy Sheet 50-60
High Carbon Steel 70-80
Malleable Iron 80-90
Mild Steel 80-110
Mild Steel Sheet 80-110
Medium Hard Cast Iron 70-100
Soft Cast Iron 100-150
Plastic and Bakelite 100-150
High Tensile Bronze 70-150
Commercial Brass or Bronze 200-300
Aluminum 200-300
Aluminum Sheet 200-300
Magnesium 250-400
Wood 300-400

At a cutting speed of 200 ft/min for aluminum,

Drill bit dia (in) RPM = 3.8*CS/Dia
0.1 7,600
0.125 6,100
0.15 5,100
0.175 4,300
0.2 3,800
0.225 3,400
0.25 3,000
0.275 2,800
0.3 2,500
0.325 2,300
0.35 2,200
0.375 2,000
0.4 1,900
0.425 1,800
0.45 1,700
0.475 1,600
0.5 1,500

As a sanity check, the calculated RPMs for the smaller drill bits are
commensurate with the drill speeds recommended by rivet manufacturers
for drilling aluminum. Note that the RPM table in the tool catalog
uses a cutting speed of 250 ft/min for aluminum whereas I used 200
ft/min.

Here is a small (30 KB) gif picture of the drill speed table from the
above mentioned tool catalog. I'll leave it up for just a few days.

http://www.AirplaneZone.com/Newsgrou...ill-Speeds.gif


David O