This is not your father's Menorah.  The Grunambulorah is made from old radio tubes, LED's, plumbing fittings, knife switches and it's all powered by 2 AAA batteries.  I love the warm glow and it's got that funky Steampunk vibe.  Here is how I did it.


Step 1: Materials and tools

  • Dremel with 1/4 inch glass cutting bit.
  • 3/16 inch regular bit to elongate the hole inside of tube
  • Table Saw
  • Tape Measure
  • Hammer
  • Drill with 1/16, and 1/8  inch bit to drill pilot holes
  • Soldering Iron
  • Heat gun to shrink tubing.
  • Sandpaper
  • Screw driver
  • solder
  • 18 gauge wire
  • 9 knife switches
  • 9 red led's
  • double AA battery holder
  • 2 AA batteries
  • 9 radio vacuum tools of assorted heights
  • 9 47-ohm 1/4 watt resisters 
  • 9 copper pipe connectors with 1 1/8 inch inside diameter
  • 9 PVC caps with 1 inch diameter
  • Oak 1/4 inch thich
  • Hot glue
  • Gorilla Glue
  • White Carpenter's Glue
  • Screwdriver
  • Hammered brass spray paint

Step 2: Drill the vacuum tubes

  1. For safety wear eye protection.  The bit will send small glass particles flying.  The Dremel does not actually drill the tube but actually grinds it gradually. 
  2. Decide where to drill the tube.  The best placement is somewhere you will be able to feed the LED up so that the whole tube glows.  Tubes have a layer on the bottom that would shield the light but the layer is easily drilled thru
  3. Put a drop of cutting oil on the tube.
  4. Put the dremel on high speed and let the bit gently rest on the glass.  It will begin to grind away the glass.  DON'T push it or the tube will break.
  5. Put more oil on about every 5-10 seconds.  Don't let it dry out.
  6. Be especially careful just at the end and don't let the Dremel slam into the tube.
  7. remove the small piece of glass from the drill bit.  See the photo.  It looks like a small button.
  8. use a 1/4 or slight smaller drill bit to pierce the bottom shield of the tube so that you can feed the LED up.
Remove these adsRemove these ads by Signing Up
jimmysymo10 months ago
Dear Sir, Mr,Grunambualx.Thanks for your prompt reply. Yes I contacted E-bay BUT
they don't send electronic things to Israel.(May be there afraid we'll make an H.BOMB)
:-) :-). So as you say ,If you can buy, ask Post office price of mail and I would happyly send more for you trouble, I have a Pay Pal no problems;
Thanking you in advance I remain faithfully James...
jimmysymo10 months ago
Mr.Grunambula ,You write in no4 Bus then in no5 you write buss ..WHAT are these ?
BUS or BUSS things? ALSO you say in no 2 attach the risister to the knife switch,(Which side round is the resister) OTHER than this, a very good Instuctable. jimbo.
Grunambulax (author)  jimmysymo10 months ago

Grunambulax (author)  jimmysymo10 months ago
Hi jimysymo

The bus simply refers to a common positive and negative lead. You could use a single strand of wire and solder all the negative and positive connections to it or you could bunch them together and use a wirenut. I think running a negative and positive rail makes it look more finished.

Re resister, as long as the resister is between the positive battery terminal and the led it will drop the voltage. It doesn't matter if it is before or after the knife switch as it is a series circuit.

Dear Sir, Grunambylax. Thanks for the feed back ,now I understand.
Also may I ask in the future,if I have other problems for your HELP
Have a good month ie Christmas,,, New year and LIFE. :-)
Grunambulax (author)  jimmysymo10 months ago
Dear Jimmysymo

Thanks you and best wishes to you too at Christmas and the New Year

gravityisweak10 months ago
Just one question, do you have any links to the glass cutting attachment that you used to cut into the vacuum tubes?
Grunambulax (author)  gravityisweak10 months ago
Dremel 663DR 1/4-Inch Glass Drilling Bit with Cutting Oil
gravityisweak10 months ago
Thanks so much on the how-to for drilling an led into an old vacuum tube! Ive been looking for a way for a while now!
Grunambulax (author)  gravityisweak10 months ago
Thanks gravityisweak. I hope it helps.
Use water when cutting glass and don't waste your expensive cutting oil.
Grunambulax (author)  The Lightning Stalker10 months ago
Thanks for the tip.
Also if you use a drill press the slower speed won't crack the glass as it stays cooler. To keep the water in place create a dam wall with some blu tac.
Grunambulax (author)  bricabracwizard10 months ago
I'll have occasion to try this out with another project. Thanks.
bhardy610 months ago
Hava nagila ve-nismeḥa!!!
Grunambulax (author)  bhardy610 months ago
Thanks. I always wondered how you spelled that.
Junophor10 months ago
Hi Grunambulax

A very goo inspiration
Where do you get those knife switches
I´m looking for them several years without success

If you can tell me an adress to order some, would be nice;-)))
Yours Aeon Junophor
jcvillar Junophor10 months ago
i get my knife switches on eBay.
Grunambulax (author)  Junophor10 months ago

I got them from Amazon. com. They are 10 for $10.50. The link is above. I also saw double pole.
Hi Grunambulax
Thank you for sharing this link

I ordered two packs them and looking happily forward because of using the right switches for my steampunk objects then;-))))

Greetings from Germany

Yours Aeon Junophor
kasssa10 months ago
Chag Sameach! Maybe next year...
Grunambulax (author)  kasssa10 months ago
I look forward to seeing it!
hohum10 months ago
toooo cooool!!!
Grunambulax (author)  hohum10 months ago
Thanks for the compliment. And I see you found the resister values. Good.
hohum10 months ago
47 ohms,, thanks
hohum10 months ago
very cool project, what size of a current limiting resistor are you using?
bob303010 months ago
Very nice. I like the steampunk look. Thanks for posting.
Grunambulax (author)  bob303010 months ago
Thanks bob3030!
longwinters10 months ago
Love it, as Dennis Miller says shalom aloha, perfect timing, (almost) ya coulda posted this in time to finish it for this year.
Grunambulax (author)  longwinters10 months ago
Well sleeeecha! I only wish I was organized enough to do this ahead of time. You are seeing photos taken barely after the hot glue became cold glue.
technologyguy10 months ago
Love it! I'll definitely be building one. Especially like your method of drilling old tubes and lighting them with LED's. Lots of other possibilities there. Keep up the good work!
Grunambulax (author)  technologyguy10 months ago
Thanks technologyguy! I look forward to what you come up with. I just looked at your portfolio and there are a lot of interesting and creative builds there.