Making 4-11/16" Holes in Al Panel

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.
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I need to make some holes in an aluminum instrument panel. The panel is 1/8 inch thick
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On 15 Dec 2003 19:26:36 GMT, snipped-for-privacy@aol.com.gov (Rileyesi) wrote:

Im happy for you. I need to replace the front wheel bearing in the drivers sided front.
" ..The world has gone crazy. Guess I'm showing my age... I think it dates from when we started looking at virtues as funny. It's embarrassing to speak of honor, integrity, bravery, patriotism, 'doing the right thing', charity, fairness. You have Seinfeld making cowardice an acceptable choice; our politicians changing positions of honor with every poll; we laugh at servicemen and patriotic fervor; we accept corruption in our police and bias in our judges; we kill our children, and wonder why they have no respect for Life. We deny children their childhood and innocence- and then we denigrate being a Man, as opposed to a 'person'. We *assume* that anyone with a weapon will use it against his fellowman- if only he has the chance. Nah; in our agitation to keep the State out of the church business, we've destroyed our value system and replaced it with *nothing*. Turns my stomach- " Chas , rec.knives
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Rileyesi wrote:

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.

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?skuC57174
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."

-- 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."
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--------------000806090703080104030104 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit
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:

--------------000806090703080104030104 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <meta http-equiv="Content-Type" content="text/html;charset=ISO-8859-1"> <title></title> </head> <body> Kinda cool design. &nbsp;If implimented with quality, it could actually work. &nbsp;I dobt that the quality would be high enough from HF though to really trust it.<br> <br> And this brings forth a question....what would the best way to grind the cutting points be? &nbsp;In my application, I would love to be able to cut blanks from 2" thick UHMW that are about 8" in diameter. &nbsp;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. &nbsp;I assume the torque would be tremendous so having the cutter wrong would shut you down pretty quickly. &nbsp;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.<br> <br> Any comments?<br> <br> Koz<br> <br> Jeff Wisnia wrote:<br>
<pre wrap="">Jeff Wisnia wrote:
</pre> <blockquote type="cite"> <pre wrap="">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:
<a class="moz-txt-link-freetext" href="http://acmehardware.com/product_detail.aspx?skuC57174 ">http://acmehardware.com/product_detail.aspx?skuC57174 </a> </pre> </blockquote> <pre wrap=""><!----> Here's a design variation I haven't seen before. Looks like it'd be worth $10.
<a class="moz-txt-link-freetext" href="http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumberD499">http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumberD499</a>
Jeff
</pre> </blockquote> <br> </body> </html>
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Google on "trepanning cuts" - Google Tells All, soon to be recognizable by the acronym GTA .. - GWE
Koz wrote:

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Koz wrote:

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."
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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.

The
mill,
hole
need.
an
have
Digi-Key
I
19
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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
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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 shit 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 ================================================
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A fly cutter, very slow, lots of lube, perfect ridgitity in holding and tool.

The
mill,
hole
need.
an
have
Digi-Key
I
19
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Rileyesi wrote:

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
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