Initially, the DIY master planned to make a hairpin out of wood, and place a special printed circuit board (PCB) with LEDs on top. However, then he came up with the idea to make a hairpin in the form of an “endless mirror”, and the very base to be printed on a 3D printer and electroplated with copper.
Tools and materials: – Metal spoke; – Electrically conductive nickel paint; – Sulfate pentahydrate copper; -Crocodile clips;
-Glass or plastic high container;
-Batteries type AA – 2 pcs;
-Mirror film; -Mirror plastic disc 1 “; – SMD -LEDs 1206; -Resistor 330 Ohm;
-Glue gun; -Soldering iron;
-A tool for stripping wires;
-Transparent acrylic spray-coating;
-Heat shrink tube;
Step one: 3D printing
The first step is to print the disc on a 3D printer.
The first CAD project was developed for LEDs of a different size. He then made some changes and updated the design files to match the 1206 SMD LEDs. You can download the file for printing below.
OnShape Full CAD
He also designed a stub that will not be used in this assembly, but they are suitable for assembly. The files can be downloaded below.
After printing the ring, he sanded the part to create a rough surface.
Step two: back
Since the back was not printed, the craftsman cut it out of a plastic bottle. The back must also be sanded.
Step three: preparation for electroplating
Plastic parts are used in the construction, and as you know for Electroplating needs metal. To give the ring conductive characteristics, the master decided to apply a special paint to it.
There is a warning on the nickel cylinder that it is very toxic, so work should be done either outside or in a well-ventilated area.
There is no need to paint the spokes as they are made of stainless steel, which conducts electricity.
When painting, only paint the parts that need to be copper-plated. Since copper is conductive, he tried not to paint the inside of the ring, where the battery and other electrical parts will be located.
Paint is applied in several layers.
Step Four: Electroplating
This is the first experience of a DIYer in electroplating.
First, the master prepared a solution of copper sulfate. Dissolve copper sulfate in water. The master does not give proportions, but there is a lot of information on the Internet. In addition, other acids can be used as acid, up to lemon juice or vinegar.
The master uses three AA batteries connected in series as a power source.
Using clamps, the positive end is attached to a piece of copper and the negative end to one of the spokes. Then he places the hairpin and the copper electrode in the container with the solution. The copper and the hairpin should not touch.
To get a good even coating, the master had to clean the previous one several times and reapply the coating. The fact is that copper covers the part unevenly and with a roughness. Film In general, the process took a long time.
After applying a good coating, you need to dry the clip and varnish it.
Step five: scheme
Next, you need to prepare the LEDs. The original idea was to solder the LEDs to a copper strip. Unfortunately, as mentioned, the groove in the 3D printed part was too small (for some reason he designed 0603 LEDs instead of 1206 in CAD).
As a result, he stripped the insulation on the wire and soldered the LEDs directly to the wires, at regular intervals and in one orientation.
Then he assembles and tests the circuit on a breadboard. After making sure that it works, he puts the LED wire into the groove of the ring.
Step six: building
As you can see, the ring is divided into two parts. One part contains LEDs and a mirror film, the second contains a battery, a resistor and a switch.
The mirror film is cut and glued behind the LEDs. Transparent acrylic is glued on top.
On the reverse side, the electrical parts are fixed and the cover is installed.
Everything is ready.