Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.


Thanks,
Rich

I've heard it said that machining aluminum is like machining wood.

Ok, that's not entirely accurate, but...

I'd be inclined to cram a roughing endmill through there and take it all out
in one pass, letting the slug drop through. I'd do the same with 3/4" tool
steel given a capable machine. While you won't need a hacksaw, your arms
will probably be pretty tired by the end of the run.

How large of an internal radius (in the corners) can the application
tolerate? Obviously, the larger the rad, the larger the cutter, the heavier
the cut. You'll want less flutes as opposed to more flutes (for chip
clearance). LOTS of coolant. Your table will probably be overflowing by the
time you've finished a couple of pieces.

If your machine has a DRO, you'll have an easy time. If not, I'd be inclined
to set up a bunch of indicators or stops to make the job go quickly. 24pcs
is enough to justify a longer setup, IMHO.

Good luck and don't forget the coolant!

Regards,

Robin

"njrich" wrote in message
om...
Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.


Thanks,
Rich

"Robin S." wrote in message
...
I've heard it said that machining aluminum is like machining wood.

Ok, that's not entirely accurate, but...

I'd be inclined to cram a roughing endmill through there and take it all
out
in one pass, letting the slug drop through. I'd do the same with 3/4" tool
steel given a capable machine. While you won't need a hacksaw, your arms
will probably be pretty tired by the end of the run.

How large of an internal radius (in the corners) can the application
tolerate? Obviously, the larger the rad, the larger the cutter, the
heavier
the cut. You'll want less flutes as opposed to more flutes (for chip
clearance). LOTS of coolant. Your table will probably be overflowing by
the
time you've finished a couple of pieces.

If your machine has a DRO, you'll have an easy time. If not, I'd be
inclined
to set up a bunch of indicators or stops to make the job go quickly. 24pcs
is enough to justify a longer setup, IMHO.

Good luck and don't forget the coolant!

Regards,

Robin


Robin,

Suggest dont confuse him further, looks to me he may already be already in
deep trouble here as it is.

--

SVL

Subject: Making square holes in thick Aluminum Plate
From: (njrich)
Date: 20/11/04 04:24 GMT Standard Time
Message-id:

Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.

If it was just one hole you could do it any way that came to hand. For 24 holes
in 3/4" plate you could be there for a couple of days with the wrong method.
Ideally it wants a laser cutting machine which would slice them out in a few
minutes. You might be better off finding someone who can do that and adding a
markup.

If you have to mill it out then I'd suggest a smallish 2 flute milling cutter
and do it in maybe 2 passes each 3/8" deep. Forget sawing. You'll still have to
clean up the edges and the sawing won't actually save you much milling time.
--
Dave Baker - Puma Race Engines (www.pumaracing.co.uk)

Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.


Thanks,
Rich
You may want to make a template, then use (since you are a woodworker)
a hefty router with the proper bit (carbide tipped) and run the router
around the inside of the template, increasing depth over 3 or 4
passes. A router *will* cut the aluminum and 3/4 depth isn't all that
much. HTH
Ken

"njrich" wrote in message
om...
Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.

How about finding someone with a large broaching machine? If you drilled the
holes first it might not be all that expensive.

Leon
--
Leon Heller, G1HSM
http://www.geocities.com/leon_heller
http://www.kasamba.com/viewExpert.as...1&banID=21 00

(njrich) wrote in
om:

Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.


Thanks,
Rich


Find the closest shop near you with an abrasive jet machine and send them
to him. Abrasive jet can do this in a very short amount of time, at a
very, very reasonable cost.


--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

If you start with a pilot hole you can use a down spiral roughing bit
that will shove the swarf out the bottom, MUCH easier to see what is
going on.

But someone else mentioned water jet, the only way to go.

Ken Sterling wrote:

Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.


Thanks,
Rich

You may want to make a template, then use (since you are a woodworker)
a hefty router with the proper bit (carbide tipped) and run the router
around the inside of the template, increasing depth over 3 or 4
passes. A router *will* cut the aluminum and 3/4 depth isn't all that
much. HTH
Ken

Use a hole saw that is 2" diameter. 1. Lay out the holes. 2.Drill small
holes in the corners, maybe 1/16" diameter or smaller. 3. Drill out
the 2" hole.
4. Finish by removing the remaining stock (not much) with an approriate
milling cutter. File corners if you need to.
I had to do this for 14 holes of 3 different sizes (3/4", 7/8" and
1") in 1" thick steel plate once. I used this process, but the
dimensions had to be closer. So I used my shaper with a square,
relieved on all four sides cutter to remove all the remaining material.
Pete Stanaitis
---------------------------------------

njrich wrote:

Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.


Thanks,
Rich

Hi- you could waste most of the stock with a good hand held saber saw with a
coarse blade with lots of set.
If its tough going, cut a series of holes around the perimiter, say 1/4 inch
dia. on 3/8 centers before using the saber saw.
Finish with a file like bump and paint guys use on lead- or a 1" wide
vertical belt sander designed for internal sanding- or with a single pass in
the vertical milling machine, or some combo of these. I would layout the
holes with layout dye and prick punch along the lines
in case the line gets "lost". Be aware that alum. can be tricky to
drill-flatten the cutting edge a little on a stone. Consider
clamping two or more plates together to save time. Consider bandsawing out
the hole without breaking the blade and then welding the slot closed.
Perhaps the saw slot could be left as is; no way for me to tell. I think my
24'' Delta floor mounted scroll saw could cut the aluminum with one starting
hole. I think you will find trying to cut multiple depth cuts with an end
mill
more trouble than it is worth. Regards, jim

njrich wrote in message
om...
Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.


Thanks,
Rich

I like #3:

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

Mill to tolerance. Don't forget to ask the designer / customer if you can drill
1/4 holes directly *on* the corners so there's no inside mill radius. Getting a
yes on that will save you hundreds in labor, so lean on it. Don't take no for
an answer unless it's a work of art, and you have to file out those corners
square for appearance.

If it's functional, 1/4 holes in the corners just show that you are thinking,
not wasting someone else's money. With a tolerance of

. + or - .01

anyway, losing 1/8 inch out of the corner of a 2 inch square hole is a quibble.

You can finish 3/4 inch plate with a 1/4 inch long end mill, barely, but to
hog, use 1/2 inch.

Consider locking the spindle somehow ( Does your belt need replacing anyway?
Nail a plywood board between the belt legs) and using a carpenter's mortising
chisel to square the corners, with the ram stroke on the mill, and feed of
0.005 diagonally, that is 0.004 on x and y should do, per stroke. Maybe a
little less near the corner, to finish. Feel for the feed, use judgment.

Square the chisel to the table by clamping a bit of tool steel to it.

Or send it out to be water jet cut NC. Fast, easy program to write. More than
one part, so programming amortizes.


I tolerance everything and tolerate everyone.
I love: Dona, Jeff, Kim, Kimmie, Mom, Neelix, Tasha, and Teri, alphabetically.
I drive: A double-step Thunderbolt with 657% range.
I fight terrorism by: Using less gasoline.

To find waterjet / abrasivejet shops, visit:

http://www.omax.com/job_shop_match.html

or

http://www.waterjets.org/waterjet_jobshops.html

- Carl
http://www.waterjets.org


Find the closest shop near you with an abrasive jet machine and send them
to him. Abrasive jet can do this in a very short amount of time, at a
very, very reasonable cost.

I do not have my catalog handy, do those drill bits (Watts drills) for
square holes go as large as 2"?
--
wf.

Ken Sterling wrote:

Gentlemen,
Hope you are fine wherever you may be.

I have a job which came my way which calls for making 2"x2" square
holes in 3/4 inch aluminum plate.
I am a construction worker, carpenter, with access to a heavy
mill-drill machine and a small home shop size band saw. I have to make
24 of these square holes in separate 5" x 6" x 3/4" sections. The
tolerances are not tight. + or - .01 inches is ok.

My question is what is the best way to do this? From what I can see
there are three choices.

1. Layout the square, drill a 5/8 hole, put a hacksaw blade through
and start hacking away. Finish off
using an end mill. Of course I might need a new set of arms when I'm
done. i need a new brain already!

2. Due the same but weld the bandsaw blade through each plate and cut
using the band saw before
finishing with the mill.

3. Drill out a square shape formed by a series of holes using a 1/4"
drill bit and finishing with the mill.

My 3 ideas might suggest to you that I have little experience with
machining metal. And that would be
quite true. So I would appreciate your suggestions.


Thanks,
Rich
You may want to make a template, then use (since you are a woodworker)
a hefty router with the proper bit (carbide tipped) and run the router
around the inside of the template, increasing depth over 3 or 4
passes. A router *will* cut the aluminum and 3/4 depth isn't all that
much. HTH
Ken