Vacuum Tube LED Candle

Vacuum Tubes are an amazing thing to behold. They look like miniature works of art made by a mad scientist! I recently came to own some used vacuum tubes which were no longer functional. Instead of sticking them into a draw or god forbid – throw them away, I decided to work on ways to display them.

For this ible’ I decided to mount one in a block of wood and add a flickering LED. You could just mount the tube into the wood without the LED but I wanted to give it a little life. As the block of wood is solid you will need to carve out a recess for the battery and switch. This isn’t too hard as long as you have some chisels.

Parts

1. Vacuum tube. – eBay

2. Wood. Any old piece of wood as long as it has some character

3. 2 X AA Battery holder - eBay

4. 2 X AA Batteries

5. Wires

6. Switch – eBay. I used quite a large switch which was more time consuming to add. It would be simpler to add a smaller toggle switch – leave it up to you though.

7. Brass strip – eBay

8. Flickering LED - eBay

Tools

1. Drill

2. Sander

3. Soldering iron

4. Pliers

5. Chisels

6. Vice

7. Double sided tape

8. Oscillating multi tool

Steps:

1. Choose your wood. I used a piece of drift wood I found at the beach some time ago.

2. As I was using an old piece of wood, I had to sand it back which revealed some beautiful wood underneath the weathered surface

3. Cut to the size that you want to make the stand. Remember you need to add the switch as well so don’t make it too small.

Once you have the wood sanded and prepared, you next need to mark out the area that you need to cut out for the battery holder.

Steps:

1. Place the block of wood into a vice to hold it steady

2. Place the battery holder onto the wood and trace around

3. To make the initial cuts I used an oscillating multi tool which you can see an image of below. I found that this made the job of removing the battery section very easy.

Steps:

1. Grab a chisel and start to remove the marked section. I used a large head chisel and carefully removed the wood.

2. Check your work by placing the battery holder into the battery section and seeing how it fits

3. Keep removing the wood until the battery holder fits into the hole. Make sure you have about 5mm of wood over the battery holder.

Steps:

1. To make the perfect sized hole, I used a 19mm wood boring drill bit. These are also known as flat or spade drill bits and they look like the one in the image below.

2. Find the centre of the wood and start to drill. The hole can go right through to the other hole you made for the battery as it won’t affect the way the vacuum tube sits in the wood.

3. Once drilled, test to make sure the tube sits well in the hole. You shouldn’t have to glue it into place as the fit is nice and snug.

I added quite a large switch but you could easily add a smaller toggle switch if you wanted to. Also, I added a piece of brass to cover up any holes made in the wood

Steps:

1. First mark out the size of the switch onto the wood

2. Next, use a drill to remove most of the wood. You will need to drill right through the wood

3. Grab a small chisel and start to remove the wood in the inside of the hole. Be careful though not to chip the sides. If you do, grab some super glue and stick it back on. You can sand it back later.

4. Keep on trying the switch until it fits into the hole made

5. Add some wires to the terminals on the switch

6. Drill a small hole from the battery compartment through to the switch hole. Pass the wires from the switch through the hole and into the battery compartment.

7. Push the switch into place

8. Cut a strip of bass so it is big enough to cover the hole and drill a hole in the middle for the switch.

9. Place the brass over the switch and add some super glue to the bottom of the brass and secure into place.

Steps:

1. Solder one of the battery wires to the switch wire and add a little bit of heat shrink.

2. Thread the other wire from the switch and the battery through the hole in the top of the wood

3. Secure the batteries into place with some good quality double sided tape. I use the foam type tape as it works the best.

To bring out the grain in the wood, I added some bees wax.

Steps:

1. With a clean cloth, rub some wax all over the wood. Make sure you rub it in well and get it into all of the grain of the wood

2. Wipe off the excess wax with another rag.

Steps:

1. Trim the LED’s legs.

2. Next, add some solder to the legs and the wires coming out the top hole. Before you solder the LED into place, test to make sure you have the correct polarities on the LED.

3. Solder the LED into place and don’t forget to add some heat shrink.

4. Test

Steps:

1. First you will need to remove the middle section of the vacuum tube. This is a plastic part which has a glass cylinder down the middle.

2. Place the tube into a vice (obviously not the glass section, just the plastic base) and with a pair of wire cutters, start to chip away at the plastic

3. Remove all of the plastic until it is flush with the base

4. Give the tube a shake to remove any broken glass inside.

5. Push the LED inside the hole. There shouldn’t be any need to hot glue it into place

6. Push the vacuum tube into the hole in the top of the wood. The legs on the tube will hold it into place.

7. You might need to work out the best position for the LED so if you find it isn’t in the correct position, pull it out and try again.

That’s it!

Hopefully you have a very cool looking vacuum tube and stand. The soft glow of the flickering candle helps bring this marvel of electronics back to life.

Next I’m thinking of making a display stand for a whole bunch of different types of vacuum tubes.

Thanks for checking it out and happy making