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Archive for February 25th, 2016

Vacuum Tube LEDs: Platter Chassis

Given that Greenlee chassis punches fit the ersatz vacuum tube sockets, this makes a certain perverse sense:

Greenlee puch on hard drive platter

Greenlee puch on hard drive platter

This set of punches is probably worth its weight in, uh, tool steel, because Greenlee got out of the Radio Chassis Punch business quite a while ago:

Greenlee 730 Radio Chassis Punch Assortment

Greenlee 730 Radio Chassis Punch Assortment

As far as a Greenlee punch is concerned, a hard drive platter looks a lot like thin aluminum sheet:

Greenlee punched drive platter

Greenlee punched drive platter

I lathe-turned that white bushing to align the hard drive platter around the screw inside the punch. The right way to make that bushing in this day & age definitely involves 3D printing, but I was standing next to the lathe and spotted a nylon rod in the remnants bucket underneath.

The inner ring crumples around the bushing inside the die, while the platter outside remains flat & undamaged through the entire experience.

I match-marked the socket & “plate cap lead” holes on the punched platter and introduced it to Mr Drill Press, but the right way to do that for more than one socket / plate involves a Sherline mill fixture and some CNC.

And then It Just Worked:

Vacuum Tube LEDs - IBM 21HB5A drive platter socket

Vacuum Tube LEDs – IBM 21HB5A drive platter socket

That’s obviously a proof of concept; the socket rests on the desk with the rest of the tubes / sockets / Neopixels tailing off to the right. The plate cap lead should pass through a brass tube fitting on the platter, just for pretty.

The 7- and 9-pin sockets have a raised disk that’s slightly smaller than the 25 mm hard drive hole; the easiest fix involves slightly enlarging the disk to match the hole. Although CDs / DVDs have a 15 mm hole and Greenlee punches work surprisingly well on polycarbonate, if I’m going to CNC-drill the screw / wire holes anyway, CNC milling the middle hole should go quickly and eliminate a messy manual process.

Come to think of it, that big tube would look better in the middle of a DVD amid all those nice diffraction patterns from the RGB LEDs in the cap…

 

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