I saw this on ibles from JustAddSharks' DIY Heng Lamp and thought it looked really cool and just decided to go ahead and make one myself. The main difference is that I elected to use 3D printing instead of laser cutting to make the lamp body. It might not be as aesthetically pleasing as JustAddSharks' (or the original kickstarted heng lamps) but it was easier with the tools I had. It is a cool looking lamp and I like the magnetic actuation!
The whole project can easily be done in a day if you have all the parts and access to a 3D printer and soldering iron.
Step 1: Materials & Parts
I had all the parts already so I don't have any links to share. That being said there aren't many components needed and they should all be cheap.
- 3D Printer
- Soldering iron
- Dremel (a single hole to be drilled, could be done another way if you don't have this)
- LED strip (I used a densely populated white LED strip)
- 12V power supply (shouldn't need much power)
- DC barrel jack (or solder your wires right into the base from the power supply)
- Micro-switch (with long enough lever arm to tie some string to)
- String or thin wire
- Magnets (1/2" diameter, fairly strong(#?)). You need at least 2x magnets.
Step 2: 3D Printing
Get started with the printing first since it will take some time. All the files can be found on thingiverse (thing:2137279). You may need to chop the print file if you have too small of a print bed.
You will need to print 1x of each of the heng lamp halves and then 4x of the magnet holder halves.
The two halves are mirrored and additionally one of the halves has a block where you can mount the micro-switch.
I printed them in PLA but the material does not matter.
Step 3: Magnets
First, run a thin wire or string through the loops in the printed holder halves. Do not tie a knot around them yet. This will keep them together though and is easier to do before inserting the magnets. I used 26 gauge uncoated wire here but think that thinner wire would have been nicer.
I then filled 4x 1/2" magnets in each magnet holder. The number of magnets used isn't important, it is just to fill the space.
For the string, you can either knot it now to hold the 2 halves tight together or leave it loose if it moves easily enough to tie later. You will need to play with the string length that you want. The top string will need to be tied to a clip of some sort (see picture 3) so that it can be held in place at the top. The bottom string will be tied to the lever of the micro-switch.
Hold the two halves closed. I used a soldering iron to melt ("weld") the halves together permanently.
Now is also a good time take the LED strip and approximate how long of a strip you need and also figure out where the half-way point is in that strip. In my LED strip I could drill straight through the middle of the strip in-between segments of LEDs. I drilled this hole so that there was a place for the wire/string to come through. You should do this now and feed the top string through the LED strip. (pictured in image 3)
Step 4: Electronics
The electronics are very simple here; it is just a switch between the power supply barrel jack and the LED light strip.
I bent the lever arm of the switch up so it would fit in the enclosure. I also bend the tip of the lever around 180 degrees so that I had something to tie the string to. Make sure to crimp the tip of the lever around your string so that the string can't fall out.
I soldered all the connections and mounted the DC barrel jack and micro-switch (with a couple small screws) but left the LEDs dangling for now.
Step 5: Final Assembly
Once the electronics are in place and you think you have the strings adjusted to the right length you can close the whole enclosure. Make sure everything is in the right place because we won't be able to open this again.
One last thing to mention, it might be a good idea to add weight to the bottom of the base so that the lamp is held upright better. All I had readily available was some thickening silicone mold that I had to get rid of anyways. I liked the idea of using lead shot or something to weigh it down. Just make sure you don't electrically short anything.
Press the two halves together tightly. The LED strip should still be dangling out from the bottom hole but all other parts should look done at this point. Now use your soldering iron again to 'weld' the two halves together along the seams.
My LEDs had an adhesive on the back, but if yours don't you will need to also apply some double-sided adhesive (my personal favorite is 3M VHB tape). Starting from the top where you drilled a hole in the LED strip, press the adhesive against the lamp and all the way around on both sides to affix the LED strip.
You are all set to plug it in and enjoy.