air drill question

[Ded Dog]

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

[Orval Fairbairn]

In article >,
(Ded Dog) wrote:

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

It is all a function of drill size -- available in metalworking books.

[Steve Robertson]

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.

Steve Robertson
N4732J 1967 Beechcraft A23-24

Orval Fairbairn wrote:

> In article >,
> (Ded Dog) wrote:
>
> > what rpm range best for aluminum sheet metal? 2600? 3600? less? more?
> > thanks KM
>
> It is all a function of drill size -- available in metalworking books.

[Lpmcatee356]

>
>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.

[Larry Smith]

"Ded Dog" > wrote in message
om...
> what rpm range best for aluminum sheet metal? 2600? 3600? less? more?
> thanks KM

Read Veeduber's article on the subject. It's a great article chockfull of
good info. It's at Ron Wanntaja's website. What I recall is that it's
somewhere around 30,000.

[Larry Smith]

Here you go, for the air drill speed. Scroll down about 1/4 to Veeduber's
(R. S. Hoover's) Riveting 101, etc. Course, natcherly giving a nod of
approval to Ron Wanttaja's marvelous website:

http://home1.gte.net/ikvamar/avlinks/index.htm


"Lpmcatee356" > wrote in message
...
> >
> >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.

[Veeduber]

> 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

[Larry Smith]

"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.

[Del Rawlins]

On 20 Nov 2003 11:47 AM, Lpmcatee356 posted the following:
>>
>>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.

A quick and dirty back of the envelope calculation shows that a 1/8" bit
can be spun in excess of 9000 RPM in aluminum. Higher grade bits can,
of course, be spun faster, but the bottom line is that for drilling
rivet holes in sheet aluminum, no generally available drill is going to
be too fast.

I recently purchased a 6000 rpm Sioux air drill and find it to be
ideally suited for sheet aluminum work. I've worked with standard air
drills at around 2800rpm and I didn't like them as much, although they
work far better than the garden variety of electric drills, which always
seem to be too slow for aluminum, but too fast for steel. My drill
motors are the aforementioned Sioux, and a 1200RPM Porter-Cable electric
which is great for steel but will twist your arm off if you let it dig
in.

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

[Del Rawlins]

On 20 Nov 2003 08:52 AM, Steve Robertson posted the following:
> 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.

If the original poster is new to aircraft sheetmetal work he needs to
get a book even if he does find the answer to his question here. There
are just too many things that need to be looked up like bend radii and
figuring setback/bend allowance et cetera.

A drill speed chart is handy, but if you know what the allowable cutting
speed is for your bit material in the work material, you can easily
calculate the maximum RPM based on the diameter of the drill bit using
pi times the diameter. The short answer is that he isn't going to find
a drill that is too fast for drilling rivet holes in aluminum, and the
faster the drill he buys, the better it will work.

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

[Ded Dog]

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

[Blueskies]

..
"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....

[Del Rawlins]

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/woodworkers/activities/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/

[Eric Miller]

"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

[Frank]

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.

[- Barnyard BOb -]

"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

[Morgans]

"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

[Stealth Pilot]

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

[Del Rawlins]

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/

[David O]

(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/NewsgroupPix/Drill-Speeds.gif


David O

[Ed Wischmeyer]

> 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/NewsgroupPix/Drill-Speeds.gif

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

Ed Wischmeyer

[Morgans]

"Ed Wischmeyer" > wrote in message
...
>
> > 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/NewsgroupPix/Drill-Speeds.gif
>
> Great info, but it says no permission to access that page.
>
> Ed Wischmeyer

Worked for me. OE 6.0
--
Jim in NC

[Rich S.]

"Ed Wischmeyer" > wrote in message
...
>
> > 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/NewsgroupPix/Drill-Speeds.gif
>
> Great info, but it says no permission to access that page.

That's just for you, Ed. Works good for me! ;o)

Rich S.

[David O]

Ed Wischmeyer > wrote:

>> http://www.AirplaneZone.com/NewsgroupPix/Drill-Speeds.gif
>
>Great info, but it says no permission to access that page.

The file should be accessible to all by using the full url. However,
the directory listing is not accessible. I could email the file to if
you continue to have access problems. If anyone else has access
problems, please let me know.

Thanks,

David O -- http://www.AirplaneZone.com

[Roger Halstead]

On Mon, 24 Nov 2003 05:08:49 -0500, David O
> wrote:

>
>Ed Wischmeyer > wrote:
>
>>> http://www.AirplaneZone.com/NewsgroupPix/Drill-Speeds.gif
>>
>>Great info, but it says no permission to access that page.
>
>The file should be accessible to all by using the full url. However,
>the directory listing is not accessible. I could email the file to if
>you continue to have access problems. If anyone else has access
>problems, please let me know.

Thanks for the information.
Over the years I have developed a 'feel" for the speeds, but it's nice
to see them in print so I know if I've been doing it right or not.
<:-))

No problem dowloading the GIF.

You'll have to fix the return add due to dumb virus checkers, not spam
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair?)
www.rogerhalstead.com
>
>Thanks,
>
>David O -- http://www.AirplaneZone.com
>