[sp1nm0nkey]

I'd like to make some very deep but narrow cuts in a thick plate of 6061 (somewhere between 0.25 inch to 1 inches). Is there any reference to how narrow an endmill you can use for a given DOC? I've had issues with snapping endmills on very deep cuts before... are there any special endmills for deep cuts? I'm aware EDM or water jet would be far more applicable to this problem but I don't have the money right now to pay for this part to be made, and it'd be nice to do it in my own shop.

These happen to be internal cuts, I've considered slitting saws... and unfortunately I can't just stack these together. If you're curious, it's a flexure stage for an AFM.

I have a scroll saw too... though thick aluminum on a scroll saw just seems.... bad (though maybe it's not?). If you guys have any other ideas for how to make these internal cuts, I'm all ears. They're on the order of 0.01 to 0.1 inches wide. Sorry I don't have more exact figures right now... it'll all depend on some calculations I still have to make and what's actually possible. Thinner is preferable.. Obviously 0.01 won't be possible with an end mill but it'd be nice to know in general what's possible.

I should also mention I really don't care how long this takes to machine. Is there maybe some kind of cutter with a long shank that just cuts at the tip? Maybe I could whack a few mils off each pass and let my cnc run for a day or so.

[Andre' B]

Part # 43193 is 0.093" diameter with a 0.015 corner radius and a 1.125" reach. I would also get the 0.500 and 0.750 reach versions and use them in sequence.
http://www.harveytool.com/products/p...dius+End+Mills

Unlikely that you will be able to spin it too fast.
You want run out as low as possible.
On the longer reach tools take very shallow cuts 0.002 or less, I would start at 0.001 and adjust from there.
You will probably want the corner radius on your part for stress concentration reasons anyway but it will also let you feed at faster rates with the shallow cuts. The radius puts some of the cutting forces up the length of the tool instead of sideways into it.

Getting the chips out of the way will also be important, I prefer an air blast with a very little oil mist.