Best way to remove material?

[Mr Ron]

The attached drawing of the frame for my B1 switcher in 1/16 scale: the 2 pieces are bolted together for a total thickness of 0.500".My question is what is the best way to remove the material shown as shaded. The material is 6061-T651.

[John Evans]

A drill bit is commonly recognized as the fastest way to remove material.

[whateg0]

My plasma table does a fine job of stuff like that, with machining to follow as required by tolerances. If I had the choice, though, laser or waterjet would be cleaner.

Dave

[whateg0]

A drill bit is commonly recognized as the fastest way to remove material.

That would be an oddly shaped drill!!

Dave

[Mr Ron]

Drilling was my first choice followed by milling to size. Now as to drill size, what would be best; 1/4" or 1/2" closely spaced? 1/4" would mean a lot of holes; 1/2" would be fewer holes, but with the latter, more milling would be needed to remove material left behind. 1/4" would be less material left over to remove. Sounds like six of one and half a dozen of the other. Obviously a CNC mill, water jet, laser or plasma cutter would be best, but not part of an amateur's shop.

[earlgo]

This may sound off-the-wall, but how about holes as big as will fit in the waste and a jig saw or sawsall with a metal cutting blade to get the bulk of the rest, followed by the mill?
Laugh if you will, but it may trigger another better method.
--earlgo

[John Hasler]

I'd drill 9/16" and follow with a 1/2" roughing cutter, then finish with whatever you need to get your radii.

[warmstrong1955]

I agree with whateg0.
Waterjet would be deadly accurate, and more accurate than you need. The finish cut would be really easy on the eyes, and require no cleaning up.
Plasma table would do a very presentable job as well. I've had many aluminum dash panels made on a table, and just a touchup here and there with a file was all that was required.
Hand held plasma torch, you would need to leave some material, and machine to size & clean up the edges on the mill. If I was doing it myself, that's the route I would go, assuming I'm not in a rush....since that is what tools I have.

Bill

[Mr Ron]

Thanks for the ideas. Water jets, plasma, etc is out of the question. I don't have such equipment and don't want to send it out to be done. Everything I build has to be done in my shop.

[tornitore45]

I can not read the dimension but this is the way I'll do it.
If the plugs are worth saving instead of shredding into chips...
Let's say a 3/8 drill is a reasonable compromise between too many holes ant to much metal removal.
Advancing the dials an easy 0.400 each hole leaves 0.025. Possibly too narrow a web for such a low precision operation, so use a 23/64 drill the one nice and sharp you rarely use. Stay 0.050 away from the scribed line.
Connecting the holes can be done with and end mill, a hack saw, a diamond coated "Rope Saw", a hack saw blade held in handle used in pulling, or as I am know to do with a cold chisel. The trick is choosing the advance first as a round number, then pick the drill size based on the web you are comfortable dealing with.

[Mr Ron]

I've since modified the drawing shown by eliminating the blips that protrude into the waste area. This will make it easier to cut rectangular holes and can be done using DRO settings. I will first drill holes to remove waste close to the design lines.

[NP317]

When I've had jobs like yours, I have drilled each inside corner with the frames together;
Separated the frames and used a roughing cutter to mill out around the edges;
Re-joined the frames and performed the final trim milling to dimension.
Deburr, clean up, and go make a good margarita!
~RN