Light Rings - USB - LED 5V - 3D Printed

"Light Rings“ is a 3D printed bolt based 5V LED USB lamp. A design that is very different from my previous lamp publications. Although the LED light strips are more or less hidden in a U-profile, a pleasant light is still created.

The special challenge was to find a way to print the rings open hollow to put the LED strips in there.I found following solution: each ring consists of 2 elements. One element (A1 and B1) to which the LED strip is attached and one as a cover (A2 and B2). In order to be able to plug the individual elements into each other later, they are open (at the bottom). The individual ring elements are marked (at the top).

If you want to do this project, you should have some experience with soldering, because the small copper plates on the LED strips are very sensitive.

The light color is warm white. 

For fun, here are the technical data of the screw or the base: about M55, wrench size: about 90. If you consider that the largest screw that a company in Germany has produced so far has dimensions of M200 x 2.70m (!), this screw would be a mini-screw. So this means that the bolt size of the base is not at all unrealistic! 

Lamp dimensions:

H 280 mm, rings Ø 200 mm

For this project you need:

• LED strips (2 à 58cm)
• switching wire (0,22 mm²)
• USB Type A plug with cable
• soldering iron with thin soldering point
• solder
• heat shrink tubing or insulating tape
• lighter
• 2 position mini toggle switch
• wrench 8 mm
• cable tie
• double-sided adhesive tape

Optional:

• transparent PVC hose 5x8mm (120 cm)
• cutter

Here you can get some of the necessary parts:

• LED strip: https://www.amazon.de/dp/B07CGKT9B2?ref=ppx_yo2ov_dt_b_product_details&th=1 Note: the quality of the LED tape, in terms of adhesive properties - was very poor, which drove me almost to despair during assembly. But in the end I managed it.
• IMPORTANT!: I do not advise the installation of another or higher wattage light source, because of the possibly too intense heat development!
• Switch: https://www.amazon.de/gp/product/B01MXLZ7R1/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1
• USB charging adapter: https://www.amazon.de/USB-Netzteil-Ladeger%C3%A4t-Steckdosenadapter-Kompatibel-White/dp/B09NNXHPG7/ref=sr_1_5?crid=3LCD68LUWVXSM&keywords=usb+charging+adapter&qid=1679570235&s=ce-de&sprefix=USB+Charging+ad%2Celectronics%2C70&sr=1-5

Optional:

• PVC tube 5x8mm: https://www.amazon.de/gp/product/B088FFLRW3/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Note:

• There are a variety of different LED strips, including those that do not consist of individual LEDs, but rather a continuous LED surface. Of course, something like this would also be suitable. However, here the separation possibilities are only at larger distances, which could cause problems in our case.

First you have to print the following files:

• base.stl
• ring_A1.stl
• ring_A2.stl
• ring_B1.stl
• ring_B2.stl
• led-strip_cover.stl (4x)

Print settings:

• printer brand: Prusa
• printer: MK3S/Flashforge Finder
• supports: No
• resolution: 0,2
• infill: 15%
• filament brand: Prusa; Geetech
• filament color: Galaxy Black; Silky Silver
• filament material: PLA

Remark: As all parts are designed to fit very precisely, it may happen that you have to rework one or the other part a bit with sandpaper and/or cutter due to different dimensional accuracy of the printers and the different behavior of the filaments.

For this step you need:

• "ring_B1.stl"
• "ring_A1.stl"
• "ring_B2.stl"
• "ring_A2.stl"
• 2 LED strips (each 58cm)
• switching wire (0,22 mm²), red and black, in the lengths of 15 mm (red), 20 mm (black) and 2x150mm (one red and one black)
• soldering iron with thin soldering point
• solder
• wire stripper

First, the cable with the USB connector must be unsoldered. We will need this cable later.

After stripping the ends of the small pieces of wire (15 and 20 mm), solder - as shown in the picture - one LED strip - right-angled to the other. Positive pole with positive pole and negative pole with negative pole. For the wiring of the positive poles I used red and for the negative poles black wire.

It is very helpful if you tin the stripped ends of the wires and the copper plates on the LED strips before soldering.

Now take the ring B1 and glue the LED strip, starting from the place where the second LED strip is soldered at right angles.

Then take ring A1 and insert it into ring B1 at right angles. To do this, you can carefully spread ring B1. You have to pay attention to the loose LED strip. When ring A1 is in position, you can start gluing the second LED strip.

To solder the two 15cm long cables to the end of the last glued LED strip (ring A1), you have to loosen the end of the LED strip a bit. Note: I realized afterwards that you could have soldered the two cables before gluing them in ... in the end you are always smarter. 

Now you can insert the cover rings A2 and B2 one after the other and put them on the corresponding rings. Ring B2 must be placed from the outside, ring A2 from the inside. Unfortunately this is a bit fiddly!

The red and the black cable must be led through the hole in ring B (downwards).

As I did not consider that at the crossing point at the top of the ring one LED is exactly under the other LED strip, I had to cut open the strip at that point and cut out one LED and reconnect the space with the help of cables. 

This mistake can be avoided if you start by gluing the LED strip in the middle at the top of the ring so that there is no LED at the crossing point.

Now you need:

• "base.stl"
• the finished and joined rings A and B
• the cable with the USB connector
• soldering iron with thin soldering point
• solder
• heat shrink tubing or insulating tape
• lighter
• 2 position mini toggle switch
• wrench 8 mm
• cable tie

You can see very well on the pictures how it goes on now.

Solder the red cable - coming from the rings - with the red cable of the USB cable. For this, push a small piece of heat shrink tubing onto the cable beforehand. Then solder the cables. Push the heat shrink tube over the soldering point and then heat it with the lighter flame.

Now go on with the black cable. Solder the black cable coming from the rings to one of the two poles of the switch. Solder the black cable from the USB cable to the other pole of the switch.

For the final assembly you need:

• assembled light part
• assembled base
• super glue

Apply a drop of superglue to all 4 contact surfaces, then insert the light part into the base cross and press it for approx. 30-45 seconds. 

Finished is a not everyday light object! Have fun with it!

Considerations afterwards:

I thought about covering the LED strips with a transparent foil. First of all, I have no idea how to do this without much effort. Then I thought that the LED strips are quite deep in the rings and thus not particularly noticeable visually in the off-state. In the on-state, on the other hand, I feel the clearly appearing LED dots as appropriate.

For this step you need:

• "led-strip_cover.stl"(4x)
• double-sided adhesive tape
• scissors

After some time I was not satisfied and always thought that it looks somehow unfinished. Then I had the idea to design a cover so that only the LEDs are visible.

When measuring the distances of the LEDs on the strips, I noticed that they are slightly different for strips from different manufacturers. In my case the distance from LED to LED is 13.8 mm. According to this distance I designed the cover. Printed it is only 0.8 mm thick and therefore very flexible.You have to check before if this fits for your LED strip!

The fact that the lamp is already assembled does not matter. The covers can be inserted easily afterwards.

From the double-sided tape, I cut pieces of about 8x8mm and put them in every second space in the back of the cover tape.

It is important that the first slot fits well to the first LED. Then carefully place the strip into the ring.

Then use a screwdriver to press the cover firmly in the places where the adhesive piece lies underneath.

For this optional step you need:

• PVC hose 5x8mm (approx. length 115cm),1x 56cm, 2x 27cm
• ruler
• cutter

As it happens, there was a small piece of clear PVC hose on my workbench that I placed inside the ring for fun. Then I saw that it might complete the design if the two rings were completely lined with this PVC hose.

The easiest way to do this is to cut the lengths beforehand (1x 56cm, 2x 27cm).

However, it's safer if you cut the lengths specifically for your object.

The cutting has to be done in such a way that the pressure of the ends of the tubing ensures a good fit and they can't fall out.

Start with the long piece:

Place the hose inside the ring. Press it firmly into the ring. Join the end of the hose with the rest of the tube, make sure that the hose is always tightly seated in the ring, add 2-3 mm and make a mark. Take the hose out of the ring and cut it at the mark. Insert the cut hose into the ring. Make sure that the ends meet in the upper cross.

Then the two short pieces:

Press the hose at the top against the wall of the first ring, place the remaining hose at the bottom against the wall of the first ring, add 2 mm, make a mark, take it out and cut it off at the mark. Repeat with the other half of the ring.

Note:

I have had the lamp on for a long time and have not noticed any heat generation - neither on the tube nor on the PLA rings. By using the "led-strip_cover.stl" direct contact of the tube with the LEDs is avoided.

Positive effects of this procedure:

• it looks as if there were glass tubes in the rings
• the light of the LEDs is not so glaring anymore

If you're looking for color variations, here are some suggestions.

As it is ... after the release you still come up with new ideas, In this case I thought that a steel ball in the middle could have a great effect - as far as the reflections are concerned. 

Now I had the question, how should the ball be placed in the center? Hanging on a nylon thread? Or standing on a base? I decided for the last one. Because by attaching it to the top of the ball, the reflection would be disturbed at this point. On the bottom, it wouldn't bother as much.

For this update you need:

• "ballbase.stl"
• steelball Ø 25 mm
• chromed metal rod Ø 4.7 x 65 mm
• magnet
• superglue
• file

First I designed and printed a 4 arm bracket. I still had a steel ball of Ø 25 mm, as well as a chromed metal rod of Ø 4.7 x 65 mm. The connection from the metal rod to the ball could be made with one of the many leftover 3 x 8 mm magnets from other projects.

The metal rod fits very precisely into the "ballbar.stl" holder. I put the magnet and the ball on the upper end. Then I placed the whole diagonally in the cross area of the two rings and fixed it with some superglue.

I find that the lamp has a completely different appearance. In the on state, exactly the effect occurs that I had hoped for ... great reflections, as if the steel ball itself would produce light. Likewise the metal rod. 

I like this modification very much!