LED "Vacuum" Tubes

Vacuum tubes are cool to look at and hot to touch. A nice addition to a steampunk or lighting project, but require a lot of power and break easily.

This project provides a close facsimile that is low voltage, no heat, and more durable. Plus they look cool.

Wear your safety googles and have fun!

Parts:

Candy Tubes (eBay)

Vacuum Tubes (eBay)

LED Tea Lights (Dollar Store)

Tools Needed:

Goggles / Safety Glasses

Vise

Hobby Saw

Sand paper

X-Acto Knife

Needle Nose Pliers

Small Hammer

Satin or Semi-Gloss Black Spray Paint

Heavy Paper Towel

Wire Cutters

Drill

17/64” Drill Bit

Small Table Vise

2 Part Epoxy

Masking Tape

Optional Tools:

Small Drill Bit

¼” Drill bit

Silver Metal Spray Paint

Small Torch or Equivalent Heat Source

Parts:

Candy Tubes (eBay)

Vacuum Tubes (eBay)

LED Tea Lights (Dollar Store)

Optional Parts:

¼” Plexiglas Rods (eBay)

Color Changing LEDs (found in Halloween novelties, such as little ghosts)

Step 1. Preparing The Insides:

1. Wrap the tube in a heavy cloth or paper towel.

2. Lightly hit the tube until you hear it pop.

3. Carefully unwrap the tube. Be careful of the tiny glass shards.

1. Holding on to the bottom leads, clip all wires

attached to the bottom.

2. Be careful of the glass; cover area or wear gloves.

3. Cut off the bottom metal plate held on by the tabs shown.

4. With an X-Acto knife, carefully cut out the middle of the mica plate.

5. Insert an LED for size check.

. Preparing The Base:

1. You can find these LED Tea Lights at Dollar stores.

2. Remove the battery and pop the bottom off. The “flame” just snaps off.

3. Drill a 17/64” hole in the top of the base.

4. Spray paint the base with either satin or semi-gloss black (flat would work, as well).

5. The base can stay as is. These have and amber color and a slight flickering for realism. If you want, you can go one step farther by getting one of those color changing LEDs out of a Halloween novelty (such as a little ghost).

1. Wrap the tube once around

with masking tape, at a desired height for use as a straight line, as well as gripping proposes in the vise. NOTE: Don’t have the vise too tight, you’ll break the tube.

2. Cut along the edge of the masking tape with a hobby saw, turning it as you go.

1. Using 2 part epoxy, glue the bottom of the tube

innards to the base and let it dry.

2. Insert the LED through the bottom of the base.

3. Apply epoxy to the bottom of the tube.

4. Glue the tube to the base and let it dry.

5. Put the battery and battery cover back on and turn it on.

6. Done.

To

add a little more realism, here are a few more steps.

1. Drill a small pilot hole in the end of the tube.

2. Then drill the hole out to a quarter inch size. Clean the hole up using an X-Acto knife.

3. Put the quarter inch Plexiglas rod in a vice. While heating the rod with a small torch, slowly bend and twist the rod as it heats up and pull it apart slowly until it gets thinner in the middle pulling it apart it’ll get thin in the middle and then you can break, or cut it off with a pair of diagonal cutters.

4. Sand off the end.

1. After cutting it down, insert the modified rod into

the tube.

2. Mask off the bottom at a desired height.

3. Using a silver metal spray paint, spray the top of the tube.

4. You can now proceed with step four.

Ok, so I’ve gotten a couple of comments about destroying old vacuum tubes and that they may not be easily obtainable. When I was a kid you could pick up a whole box full for a couple of bucks, but now I realize that they may be needed for antique radio enthusiasts. So, I came up with a fast and easy way to make some tube innards. I would search the internet for pictures and get creative to add on to my design. This is a fast easy basis to build on.

Let’s get started:

Parts Used:

First I looked around for parts that look like what’s in a vacuum tube. I came up with some buss wire (a paper clip would work), some window screening (a finer mesh might look better), 3/8” internal lock washers, and some ½” plexiglass tubing (eBay).

Center the lock washer on one end of the tubing then, using a soldering iron, melt the washer into the end of the tube.

Cut the screen into a ½” wide strip and, using a soldering iron, melt one end into the tube.

Pull the screen around the tube twice, bent the wires down and melted that end in, as well.

Melt some wire into the end and trim, making 3 or 4 wires to keep up off the base.

Cut the tube at the screen line and melt another washer into the other end.

With pliers, bend a piece of wire, as shown, and melt it into the top.

BOOM, there you are. Not perfect, but with some pieces of shiny metal or other small parts glued on you can make this look very real.