Sorry, I accidentally sent the message before I was done blathering!

I need to make some 4-11/16 inch holes in an aluminum instrument panel. The
panel is 1/8 inch thick. In the past we have used a simple hole saw in a mill,
but those holes were 4-1/4 in diameter, so I was able to find a standard hole
saw size. So far, I have been unable to find a hole saw in the size I need.
We also punch and drill some smaller holes for a fuse (1/2 inch) and for an
8-32 tapped hole.

Can anyone suggest a good way of producing the 4-11/16 diameter holes? We have
your basic drill presses, lathes, and a manual mill available to use.

The material I have is 6061-T6. I'm using that because that is what Digi-Key
sells, to be honest. If there is a better material (must be non-ferrous), I
would appreciate a recommendation as well as a source for 20 or so at 7 x 19
inches. We are in northeast Ohio, USA.

Thanks.

Rileyesi wrote:

Sorry, I accidentally sent the message before I was done blathering!

I need to make some 4-11/16 inch holes in an aluminum instrument panel. The
panel is 1/8 inch thick. In the past we have used a simple hole saw in a mill,
but those holes were 4-1/4 in diameter, so I was able to find a standard hole
saw size. So far, I have been unable to find a hole saw in the size I need.
We also punch and drill some smaller holes for a fuse (1/2 inch) and for an
8-32 tapped hole.

Those shold be easy to drill n the drill press. For the 1/2 inch hole you can
sharpen a 1/2" twist drill so it has a profile like a flat wood cutting "spade
drill" and it'll go through those aluminum panels in one shot.




Can anyone suggest a good way of producing the 4-11/16 diameter holes? We have
your basic drill presses, lathes, and a manual mill available to use.

You can use a single point circle cutter in the drill press. Just make sure you
clamp the work down firmly with a piece of plywood under it.

Here's a link to a picture of one. Lots of different manufacturers make cutters
just like it. Mine (I've had it for the last 50 years or so) is a Greenlee brand:

http://acmehardware.com/product_detail.aspx?sku=4357174

Good luck and Happy Holidays,

Jeff

--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place
the blame on."





The material I have is 6061-T6. I'm using that because that is what Digi-Key
sells, to be honest. If there is a better material (must be non-ferrous), I
would appreciate a recommendation as well as a source for 20 or so at 7 x 19
inches. We are in northeast Ohio, USA.

Thanks.




--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place
the blame on."

Jeff Wisnia wrote:


You can use a single point circle cutter in the drill press. Just make sure you
clamp the work down firmly with a piece of plywood under it.

Here's a link to a picture of one. Lots of different manufacturers make cutters
just like it. Mine (I've had it for the last 50 years or so) is a Greenlee brand:

http://acmehardware.com/product_detail.aspx?sku=4357174

Here's a design variation I haven't seen before. Looks like it'd be worth $10.

http://www.harborfreight.com/cpi/cta...emnumber=44499

Jeff

Kinda cool design. If implimented with quality, it could actually work.
I dobt that the quality would be high enough from HF though to really
trust it.

And this brings forth a question....what would the best way to grind the
cutting points be? In my application, I would love to be able to cut
blanks from 2" thick UHMW that are about 8" in diameter. I'd have to
pilot it or it'd be almost impossible though. However, I have never
actually thought about where one needs the clearance to keep from
binding or to reduce the amount of drag/wobble on such a thing. I
assume the torque would be tremendous so having the cutter wrong would
shut you down pretty quickly. I've seen the big double cutter style in
the MSC catalog and similar...seems awfully expensive for loose
tolerance cutting of blanks to be machined later though.

Any comments?

Koz

Jeff Wisnia wrote:

Jeff Wisnia wrote:



You can use a single point circle cutter in the drill press. Just make sure you
clamp the work down firmly with a piece of plywood under it.

Here's a link to a picture of one. Lots of different manufacturers make cutters
just like it. Mine (I've had it for the last 50 years or so) is a Greenlee brand:

http://acmehardware.com/product_detail.aspx?sku=4357174



Here's a design variation I haven't seen before. Looks like it'd be worth $10.

http://www.harborfreight.com/cpi/cta...emnumber=44499

Jeff

Google on "trepanning cuts" - Google Tells All, soon to be recognizable
by the acronym GTA .. - GWE

Koz wrote:

Kinda cool design. If implimented with quality, it could actually work.
I dobt that the quality would be high enough from HF though to really
trust it.

And this brings forth a question....what would the best way to grind the
cutting points be? In my application, I would love to be able to cut
blanks from 2" thick UHMW that are about 8" in diameter. I'd have to
pilot it or it'd be almost impossible though. However, I have never
actually thought about where one needs the clearance to keep from
binding or to reduce the amount of drag/wobble on such a thing. I
assume the torque would be tremendous so having the cutter wrong would
shut you down pretty quickly. I've seen the big double cutter style in
the MSC catalog and similar...seems awfully expensive for loose
tolerance cutting of blanks to be machined later though.

Any comments?

Koz

Jeff Wisnia wrote:

Jeff Wisnia wrote:



You can use a single point circle cutter in the drill press. Just make sure you
clamp the work down firmly with a piece of plywood under it.

Here's a link to a picture of one. Lots of different manufacturers make cutters
just like it. Mine (I've had it for the last 50 years or so) is a Greenlee brand:

http://acmehardware.com/product_detail.aspx?sku=4357174



Here's a design variation I haven't seen before. Looks like it'd be worth $10.

http://www.harborfreight.com/cpi/cta...emnumber=44499

Jeff

Why not whip up a fixture to do it in your lathe? Sounds like you've done
this before and if you need to again you could whip out the fixture and
start making more chips.
"Rileyesi" wrote in message
...
Sorry, I accidentally sent the message before I was done blathering!

I need to make some 4-11/16 inch holes in an aluminum instrument panel.
The
panel is 1/8 inch thick. In the past we have used a simple hole saw in a
mill,
but those holes were 4-1/4 in diameter, so I was able to find a standard
hole
saw size. So far, I have been unable to find a hole saw in the size I
need.
We also punch and drill some smaller holes for a fuse (1/2 inch) and for
an
8-32 tapped hole.

Can anyone suggest a good way of producing the 4-11/16 diameter holes? We
have
your basic drill presses, lathes, and a manual mill available to use.

The material I have is 6061-T6. I'm using that because that is what
Digi-Key
sells, to be honest. If there is a better material (must be non-ferrous),
I
would appreciate a recommendation as well as a source for 20 or so at 7 x
19
inches. We are in northeast Ohio, USA.

Thanks.

I need to make some 4-11/16 inch holes in an aluminum instrument panel. The
panel is 1/8 inch thick. In the past we have used a simple hole saw in a
mill,
but those holes were 4-1/4 in diameter, so I was able to find a standard hole
saw size. So far, I have been unable to find a hole saw in the size I need.
We also punch and drill some smaller holes for a fuse (1/2 inch) and for an
8-32 tapped hole.

Can anyone suggest a good way of producing the 4-11/16 diameter holes? We
have
your basic drill presses, lathes, and a manual mill available to use.

The material I have is 6061-T6. I'm using that because that is what Digi-Key
sells, to be honest. If there is a better material (must be non-ferrous), I
would appreciate a recommendation as well as a source for 20 or so at 7 x 19
inches. We are in northeast Ohio, USA.

Thanks.


With the drill press, lathe and mill you've got your choice.

With the drill press, I'd use one of the adjustable-arm type piloted fly
cutters, using a piece of wood or metal under the workpiece to receive the
pilot.

With the lathe, I'd bore it, assuming that you can swing the entire panel. If
not, it's not a lathe job.

With the mill, you could use a boring head or a fly cutter. Or an end mill
with a rotary table if you want.

With a woodworking router, you could use a template with either a ball bearing
bit or a collar guide. Eighth inch aluminum is a piece of cake for a router.

Depending on how many you have to do, and how accurate you have to be, there
is always a nibbler or a file.

John Martin

Koz wrote:

Kinda cool design. If implimented with quality, it could actually
work. I dobt that the quality would be high enough from HF though to
really trust it.

Yeah, but that rectangular bar just sings out that it won't twist like
the "round" bars on the "standard design" cheapies. My Greenley's got
several mash marks on the setscrew side of the bar evidencing times I
got sloppy and the cutter jammed up on me. 'Course maybe that acted as a
"safety valve".

It's hard for me to imagine much that could be seriously wrong with that
HF one, even if you had to swap in a better tool bit.

Just my .02

Jeff
--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone
to place the blame on."

In article , Rileyesi says...

I need to make some 4-11/16 inch holes in an aluminum instrument panel.

If you can afford to do this, send it out to sombody who has
an NC milling machine. A 3/8 inch diameter end mill will
walk around that circle in short order. They can also do
the other holes as well, including putting in D-shaped
holes so the various fuse holders and connectors don't
spin.

The 6061 really is **** to work with, gummy has hell. At
one time Bud would sell 2024T6 panels which are a pleasure
to machine.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

A fly cutter, very slow, lots of lube, perfect ridgitity in holding and
tool.


"Rileyesi" wrote in message
...
Sorry, I accidentally sent the message before I was done blathering!

I need to make some 4-11/16 inch holes in an aluminum instrument panel.
The
panel is 1/8 inch thick. In the past we have used a simple hole saw in a
mill,
but those holes were 4-1/4 in diameter, so I was able to find a standard
hole
saw size. So far, I have been unable to find a hole saw in the size I
need.
We also punch and drill some smaller holes for a fuse (1/2 inch) and for
an
8-32 tapped hole.

Can anyone suggest a good way of producing the 4-11/16 diameter holes? We
have
your basic drill presses, lathes, and a manual mill available to use.

The material I have is 6061-T6. I'm using that because that is what
Digi-Key
sells, to be honest. If there is a better material (must be non-ferrous),
I
would appreciate a recommendation as well as a source for 20 or so at 7 x
19
inches. We are in northeast Ohio, USA.

Thanks.

Rileyesi wrote:

I need to make some 4-11/16 inch holes in an aluminum instrument panel. The
panel is 1/8 inch thick. In the past we have used a simple hole saw in a mill,
but those holes were 4-1/4 in diameter, so I was able to find a standard hole
saw size.

4-3/4" hole saws are available. That is 1/16" larger than you want or
1/32" in radius. Do you need it closer than that?

Greenlee chasis punches are what you want for the 1/2" holes.

Sounds like an aircraft instrument panel. :-)

Ted