[jjjac]

Hello, I would like to make a very narrow slot in a thin (0.0085” thick) aluminum sheet alloy 5123. Ideally the slot would be 0.001-0.002” wide and 0.0075” deep leaving a web of 0.001” thick; I realize this is very small but I will take what I can get. I also realize that this slot is normally made with a punch in a press. But this is a very expensive trial and error process if you are dealing with a tool and die shop not familiar with this process.

I probably cannot get a tool that narrow for a milling machine. Maybe a laser is the solution, or perhaps a high force plotter with a very thin sharp blade as a tool. I am trying to replicate the score line in a typical aluminum beverage can top.Tool speed is not an issue as only a few prototypes will be made.

Thanks for any help,

Jaco

[Jim Dawson]

Actually you can buy tools that small, Bits & Bits sells them. https://bitsbits.com/ But you need to be able to turn them about 50,000 RPM. I use a cheap air pencil grinder in my spindle. I have run tools as small as 0.005 tip with good success.

As you say, this is normally done in a very tight punch press, but for prototypes this would be expensive to do. The punch & die is not that complex, but would require tight control of the shut height.

A ribbon die might be worth a look also.

Here is a picture of my setup, the grinder fits a 5/8 tool holder. Due to the design of my spindle, I can run the air line where the drawbar would normally be. But the air grinder could be set off to the side of the spindle on a bracket attached to the quill.

[jjjac]

Huum, thanks. Can you expand a bit on what a ribbon die is?

[Jim Dawson]

Huum, thanks. Can you expand a bit on what a ribbon die is?

My mistake, should have said steel rule die

[awerby]

You could probably do it with a tapered single-flute engraving cutter Harvey Tool - Carbide Engraving Cutters - Pointed , if the spindle had enough RPMs.Since it's a score line, the walls don't need to be vertical.