# Router aluminum or mill



## mototraxtech (Apr 24, 2010)

I was wondering if its possible to router aluminum flat bar to round the edges.

I have include a pic of a part I want to make but I don't need it completely machined down I just want to take a piece of 3-1/2" X 3/4" aluminum 6061 flat bar and round the edges so that it looks like the pic. Would it be easier to use a rounding tool on a mill maybe.

The part is 6 inches long also!


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## gadget_lover (Apr 25, 2010)

The rule of thumb is that aluminum can often be used with wooworking tools. I've seen people do exactly what you propose.

Keep in mind that work-working tools are, in general, built to much looser tolerances than the metal-working equivalents. A 1/2 inch mill will be .500 inches. A 1/2 inch router bit may be close to 1/2 inch. 

My neighbor works in wood. He bought a digital caliper that reads in 1/16ths and 1/32nds and is quite happy with it. 

Daniel


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## StrikerDown (Apr 25, 2010)

Never mind! oops!


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## Per-Sev (Apr 25, 2010)

If you have access to a mill that would be 100% better but other wise you can do it if you have a good cutter and clamp your stock or use a router table with a fence and if you don't have one then clamp a straight edge to the stock and set it so you can control it and take small cuts and just keep moving the straight edge over till you are at your desired radius. Just take it slow and keep pressure on the cut or you will get a lot of chatter in the cut. Using a straight edge like a fence will prevent you from taking to much off at a time.


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## 65535 (Apr 25, 2010)

If you use a router, use a router table or shaper with router bit and take small cuts. I would recommend taking different height cuts until you reach your desired radius, I have a feeling it will work better than taking multiple passes horizontally. 

I mean by adjusting the height of the cutter from the table.

We have a shaper at the wood shop i work in that allows to adjust height with good precision. If you can find something like that you are set.


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## precisionworks (Apr 25, 2010)

I've used a wood working router, in a table, to cut hundreds of feet of aluminum ... *BUT*

The router is a commercial duty unit with a 1/2" collet. Don't even think about trying to mill aluminum with a smaller collet.

The router has electronic speed control. You'll want to machine aluminum around 2000 sfpm, and 10,000 rpm is a good place to start. After you get a feel for your equipment, you'll be surprised at how much DOC can be taken per pass. Feed needs to be fast, so that the cutter is constantly cutting & not rubbing. Use carbide tipped router bits for any Al operation.

Rules #1, #2, & #3 - keep your hands & fingers well away from the spinning cutter. At 10k rpm, you can't even make out the cutter edges. Use what ever fixturing is needed to keep body parts attached to your body


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## liveforphysics (Apr 26, 2010)

65535 said:


> If you use a router, use a router table or shaper with router bit and take small cuts. I would recommend taking different height cuts until you reach your desired radius, I have a feeling it will work better than taking multiple passes horizontally.
> 
> I mean by adjusting the height of the cutter from the table.
> 
> We have a shaper at the wood shop i work in that allows to adjust height with good precision. If you can find something like that you are set.


 

Small cuts is exactly the way to fail. Like Precisionworks mentioned, the aluminum rubs onto the bit. This means OD build-up on the non-cutting areas, loads of bit heating, an awful cut, and rapid tooling failure. 


Gotta be very agressive, and you get clean cuts, cool tooling, and the bits can last way way longer than you might expect. 

When I first got my CNC setup (which uses a word-working bosche router for the spindle), I started with timid cuts and lots of passes. It made for a lot of broken tooling and awful aluminum edges. I got some advise to triple my feed rates and depth of cut both, which I thought was crazy at the time, but I gave it shot. Now I get lots and lots of hours on my tooling, and the parts come out fantastic!


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## precisionworks (Apr 26, 2010)

> triple my feed rates and depth of cut both


+1

I use the aluminum router bits made by Onsrud, who supplies bits by the thousands to CNC shops. Their tech support team is superb, and said the same thing - when they told me how many inches per second of feed, I thought they were nuts  But it improved the finish 100% and the aluminum snowflakes flew off the cutter just like in the videos.

http://www.onsrud.com/files/pdf/OC-09CatalogR.pdf

http://www.onsrud.com/files/pdf/OCMR_08.pdf

The lowest prices & best service I've found for Onsrud bits is Ballew: http://www.ballewsawandtool.com/index.php

If you can set up the nozzle of a shop vac near the cutter, clean up is much less. If not, figure more time in clean up than in milling the aluminum. IMO, aluminum cuts more like a tropical hardwood than it does metal. Those woods (Rosewood, Bubinga, Goncalo Alves, etc.) are also machined at high feed rates.


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