Advertisements

Archive for October 3rd, 2016

Vacuum Tube LEDs: Grinding Off a 0D3 Base Spigot

Rummaging in the Hollow State Electronics box produced the shapely 0D3 regulator tube with an intact spigot / key post in its base:

0D3 voltage regulator tube in socket

0D3 voltage regulator tube in socket

Because the glass envelope (1.5 inch = 38.1 mm OD) extends beyond the base (1.125 inch = 28.6 mm OD), the simple base clamp must let the tube extend over the workbench:

0D3 Octal tube - V-block clamp

0D3 Octal tube – V-block clamp

There’s no way to clamp that mess in the Sherline, so, rather than freehanding the shell drill, I misused a Dremel slitting wheel to grind away the end of the spigot, which normally extends a bit beyond the pins so you can’t possibly insert the tube into the socket the wrong way:

0D3 Octal tube - ground-off spigot tip

0D3 Octal tube – ground-off spigot tip

The missing end exposed the hole in the middle of the post and showed this tube’s evacuation tip didn’t extend into the spigot. Emboldened by that, I continued the mission until the wheel wouldn’t reach any further:

0D3 Octal tube - Dremel grinding

0D3 Octal tube – Dremel grinding

That didn’t work well, but at least I didn’t break anything and nobody will ever see those mauled pin tips.

Obviously, the only way to do this right is to clamp the tube properly and mill the spigot flush with the socket; it’s time for more 3D printing…

Advertisements

9 Comments