Best Mill for 1" thick Aluminum?

[gtslabs]

I have been researching mills and this site is great.
I plan on cutting a lot of 1" thick Aluminum in to geometric shapes and have been looking for the right mill.

I think the small taig type mills are underpowered for this type of work. I have been considering a Bridgeport but converting to a CNC might be too big of a project for me since
I have little machine shop experience. I was hoping to compensate my lack of hands on experience with a CNC operation and a lot of the "home" machines seem affodable.

Would a CNC Router be underpowered for this type of work?
And what type of precision can I get? <0.001"

Or are there any "medium sized" mills out there? I have seen the Rong-Fu but not sure of the accuracy
of these mills. Plus I don't think they have a high enough spindle speed >4,000.

Thanks
Steve

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[Spinnetti]

Thats mighty thick for a hobby machine. If you are doing production work, you might be better jobbing it out. If for hobby projects, you will have to take many passes to cut through that with a light duty machine. How about some more info about what you are trying to do?

[balsaman]

You will need to convert an existing mill to cut plate like that. The home machines you see here are for wood and very light metal work.

Eric

[gtslabs]

I am not looking to do hobby work, but prototyping and production for in-house use. Mainly I want to cut 5" diam discs with a lathe then cut a v-notch or wedge shape out of the middle. The purpose is to make "wedge grip" fixtures for in-house tensile testing of plastics. So I am looking at smooth internal faces at a set angle that would require some precision. Right now I am using MDF and a bad saw to do my preliminary work.

I want to learn more about machining and am not interested in subcontracting out at this time. But I have considered hiring a machinest part time to teach me more about how to use the equipment.

[toolmkrman]

THE ? IS HOW MUCH MONEY DO YOU HAVE TO SPEND ON SUCH APROJECT? GTSLABS IS RIGHT YOU WILL NEED TO USE A MILLING MACHINE AND RETROFIT IT.

[gtslabs]

About $5K to get started. I have been following the Bridgport type mills on Ebay and have come close to buying, but have not yet pulled the trigger. Having never used one I can only imagine the work a used one will need when I get it home. And I am hesitant to buy equipment from China as I bought an Enco bandsaw a few years ago and was dissapointed in the quality. But I got what I paid for at that time.

I run a lab and the ability to make my own equipment will save me in the long run. I was hoping to find one by the today and take advantage of the Sec. 179 deduction but I dont thing that is going to happen this year.

[toolmkrman]

I WAS JUST IN PITTSBURGH 8 DAYS BEFORE X-MAS. MENASHA PACKAGING OFF OF PREBLE OVER AT THE STATE PRISON. I HAVE A MACHINE THAT I BUILT THEY. IT IS A CARTON FORMER.

[toolmkrman]

I WOULD LOOK FOR AN OLD BOSS 5 KNEE MILL. IT IS THE OLD NC TAPE MACHINE BUT IS EASY TO CONVERT TO PC. YOU MAY FIND ONE IN YOUR PRICE RANGE. CALL SOME TOOL AND DIE SHOPS THAT HAVE BEEN AROUND IN THE 80s. ALSO HURCO MADE AN OLD TAPE NC THIS COULD WORK FOR YOU AS WELL.

[Spinnetti]

Originally posted by gtslabs
I am not looking to do hobby work, but prototyping and production for in-house use. Mainly I want to cut 5" diam discs with a lathe then cut a v-notch or wedge shape out of the middle. The purpose is to make "wedge grip" fixtures for in-house tensile testing of plastics. So I am looking at smooth internal faces at a set angle that would require some precision. Right now I am using MDF and a bad saw to do my preliminary work.

I want to learn more about machining and am not interested in subcontracting out at this time. But I have considered hiring a machinest part time to teach me more about how to use the equipment.

Hmm... I used to be a machinist (professionally), and currently have Grizzly 12x37 lathe and a Grizzly G1006 that I converted to CNC at home.. Do you have a drawing you could upload? You might spend lots of money on a solution you don't need.... If your lathe is big enough to turn the diameter ok, then a small mill or mill drill should be able to cut the groove for you ok. I don't think you need cnc for that unless you are ready for it and are willing to spend the significant amount of time required to get this up and running..

[balsaman]

ToolMkrman,

Hit the CapsLock key once. All caps is considered yelling.

Thanks

Eric

[gtslabs]

Here is a link to a pdf of the part so far.
http://www.nb.net/~gts/gripstool.pdf


The Red lines are the parts outline and the Dark Black line is my tool path 1/4" mill. The 1/4" circles are holes drilled out for alignment purposes for my prototype but I was hoping the mill could make these passes. I was trying to design a tool path that would keep the piece together for most of the cutting. In the end there would be the disc body and the 2 red jaws. The most critical part would be the angle the jaw makes with the body so the jaw face is always vertical.

[HuFlungDung]

Hi GtsLabs

That type of work (your drawing) can be easily handled with a small mill, or an accurate router. The cutter diameter is the main concern. When you start using larger cutters, then you need greater machine mass for optimum operation.

That is a very deep slot to cut, with that diameter of tool. Typically, you could do it nicely with 8 passes, 1/8" deep. However, the deeper you go, the more difficult it is to get the chips out of the cut. They start going through the cutter again, and this roughens up the wall of the part. So, your best approach, since you seem to have extra material, may be to move the wedge profile inwards a bit, and mill a 5/16 wide groove, beginning with the 1/4" width, and then taking a cleanup pass around the walls on each side of your initial groove, just before you cut through.

Oh, you should bolt the wedge to something before it breaks free, at which point it would break your cutter off for you

[gtslabs]

Hu
I have been looking at some smaller mills from Grizzly
but none of the "bench size" mills have the spindle speed
needed for Aluminum. Am I correct to say that with single phase motors I am limited to the speed. I have seen about 3000 rpm max with a single phase motor. I believe Aluminum needs >4000 rpm.

[HuFlungDung]

GT,

You don't have to run the cutter fast, unless your objective is high production rates. 3000 rpm will do fine for your purposes. Get some nice free cutting endmills, like the 45 degree flute helix type, which is recommended for aluminum. Check the maximum flute length. You will likely need an extra length series cutter to attain 1" depth. Best switch off from a regular length to an extra length part way down, because the regular length are quite a bit stiffer.

That, and a bit of coolant, and you'll be off. I would recommend an air mist unit to get the chips out of the cut, or else the messier full flood coolant stream.