Atomic Age/70s Desk Lamp From the Old Projector Lens

I love 70’s! The bright orange and red colors, futuristic (even now) shapes, thin and space themed/technological mechanical parts, slim and lightweight devices. Therefore, no wonder, that I have decided to make myself a desk lamp, styled in 70s European design. I picked up this projector objective (with missing lens) at scrap yard several years ago. It was in great shape, had nice look, and as I have found online, it belonged to slide projector from 60s. By adding a couple of additional elements, I created fully functional, practical and cool looking desktop lamp. No heavy machinery, complicated tools or skills required – everything is done with simple hand tools, and acrylic parts are cut using laser cutter (No need to have laser at your premises, you can go to any advertising company and cut it there).

Supplies

So let us start with bill of materials, what you will need. Quoted prices are average prices, taken from ebay. Some parts might be cheaper on Aliexpress (and much more cheaper on taobao)

1.     20-inch magic arm ($20).

2.     Clamp for desktop lamp ($2).

3.     MR16 LED spotlight ($1-$20, according to quality and brand). I’m using Philips spotlight, 3W, 3000K, 90 CRI

4.     20AWG wires, length according to your needs (wire should be capable of withstanding AC voltage). ($2)

5.     Nylon braiding – orange color – according to wire length. ($2)

6.     Light stand tripod head adapter, also known as "3/8 to 1/4 adapter"  ($1)

7.     Any enclosure from old lens. It should be able to adopt your selected LED module. I’m using enclosure from projector lens called “Triplet 75/2.8”. It is available on eBay, but is quite expensive, so you just can use any replacement lens enclosure.

8.     AC switch ($1).

9.     AC Plug ($1).

10.  Some screws, M3 tap, epoxy glue, screwdrivers, soldering iron, etc.

11.  Optional components: small neon bulb, two 470k-1M 1/4W resistors.

Step 1: Easy Job - All Can Be Done in a Single Step

I have used some scrap acrylic sheets to make lamp parts and decorative rings for the lens enclosure. If you do not have a laser cutter (and acrylic scraps), you can outsource making of these parts to any acrylic cutting company. I am including a PDF file, which is made in K40 whisperer (most common laser cutting software) compatible design. You will only need single A4/Letter size 3mm acrylic sheet for this. Designation of each acrylic part is shown in PDF file next to each part.

There is an intermediate part made from acrylic, in which you will have to cut couple of M3 threads, using M3 tap. The screws holding whole top assembly will go thru these holes. If you don’t have M3 tap, you can just glue M3 nuts to that acrylic plate with epoxy glue.

My LED module had large plastic rear part, which won’t fit into lens enclosure, so I removed it – this modification not only reduced overall size, but also helped to provide better ventilation for LEDs. I screwed M3 hex standoff into center of the LED module (and added a drop of epoxy glue for better mechanical strength. A centering acrylic disc is attached to the main led module and goes into narrow part of the lens tube – for centering the contents inside. There are also M3 threads cut into that acrylic sheet. Two round head screws go thru outer shell, and screw into that plate, to hold all things together.

The magic arm screw end goes thru the last two acrylic plates and is tightened from the inside with UNC ¼-20 hex nut. I used the nut and not the thumbscrew included with magic arm, because I liked that thumbscrew and decided to use it in another project. So if you don’t have hex nut of such size, use included thumb screw instead.

I also modified the thumbscrews for the magic arm and desktop clamp. I had some old, bakelite thumbscrews laying around, so I re-threaded them (M5 for magic arm, M6 for desktop clamp) and replaced inner insert with appropriate sized acrylic disc, cut from the same material, as other parts of the lamp. Since these handles are really hard to find (They came as spare parts with Specol spectrophotometer from Carl Zeiss Jena, made in early 60s), I’m not including the drawings for them. However, this does not means you have to stick with the default handles for magic arm and the clamp – use your fantasy and do it as you’d like.

Screw on the other end of the magic arm the light stand tripod head adapter (use a drop of glue on the threads for better grip) and install it into clamp for the desktop lamp. On my pictures, you can see a neat orange cover over it – this came from Oxygen sensor plug from my car 😊

For the wire I’ve used thin, but flexible, PTFE silver clad wires. You can use any kind of wires here; just ensure that they are rated for the AC voltage you are using. I used PTFE due to reason of them being very slippery, so easy to slip thru the nylon braiding.

I actually made two pieces of the cable, one goes from AC plug to switch enclosure, and another one goes from switch to lamp head.

After wire had been guided thru, I’ve attached one end to the AC plug, and another end into the switch enclosure. My switch had built-in red LED, which required low voltage for supply, and was not esthetically in line with the main light itself. So I took it apart, removed the red LED, and replaced it with the small neon bulb. I also added two resistors for it to operate properly (the neon bulb is on only when light is off). The following circuit was developed. If neon bulb light is too dim, you can reduce resistance of both resistors from 1M to lower value, but not too low, because lowering them below certain point (about 220k) won’t make the bulb brighter, but will cause unnecessary power waste and heat emission.

The “exit” wire was guided thru the rear cap of the lamp head itself, and thru intermediate acrylic plate too – to ensure tight fit and safety in case of excess force applied.

That’s all – now you have very stylish looking, cozy and practical desk lamp!