air drill question

What I recall is that it's
somewhere around 30,000.

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

Really? I sure hope not! :-)

(Mebbe I meant 3,000 ...piloting for AD3's)

-R.S.Hoover

"Veeduber" wrote in message
...
What I recall is that it's
somewhere around 30,000.

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

Really? I sure hope not! :-)

(Mebbe I meant 3,000 ...piloting for AD3's)

-R.S.Hoover

Did I say that? Pheweeeeee. Here it is, corrected. May I quote you?:

There's a handy little formula that sez how fast a drill bit of a given
diameter has to be rotating to cut a clean hole in materials of various
types.
Drilling aruminum, using a #41 bit, your drill motor has to be capable of
spinning about 3000 rpm. At that speed a sheet of forty thou is virtually
transparent to the bit. Just touch the trigger and there's the hole, nice
and
neat and round and with the smallest possible lip.

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

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

..
"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.

(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

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

Great info, but it says no permission to access that page.

Ed Wischmeyer