Introduction: Wireless Phone Charger With Resin Guide
This is a project to make a wireless phone charger out of scrap wood with a resin guide. It's a practical and attractive solution for all your charging needs. Don't waste time plunging stuff in, just sit your phone on the guide and away we go.
Supplies
What we need:-
Phone:
You must have a phone that has the wireless charging capability.
Wood:
A piece of scrap wood preferably hardwood.
Resin:
Glasscast 10 clear epoxy casting resin, Glasscast epoxy hardener and resin pigment.
Charger:
Wireless charger Gikfun Qi Wireless Charger PCBA Circuit Board Coil Wireless Charging Micro USB Port.
Finishing:
Adhesive backing.
Tools
Measuring tools:
Ruler, Set square and a good old trusty pencil.
Wood tools:
Saw, drill, palm Router + bits, chisel, clamps and a screw driver.
Resin tools:
scales, mixing cups, stirrer and a hot air gun.
Finishing tools:
Sander, polishing compound, teak oil + rag, scalpel.
Safety equipment:
Mask, ear protectors, disposable gloves.
(Don't forget to use your safety gear when using tools and pouring resin.)
Step 1: Test Wireless Charger.
Using a mini USB and USB plug socket, plug in the wireless charger. Place phone on top of the charger and see if it starts charging. If yes congratulations you can now make your wireless charger.
Step 2: Cut Wood to Size.
Firstly source a suitable piece of wood. Your piece of wood needs to be at least 40 mm wider and longer than your phone and approximately 15 mm to 20 mm thick. My piece of wood was 17 mm thick, 108 mm wide and 300 mm long. As I was using a Galaxy S10 whose dimensions were 70 mm by 150 mm, the wood was the correct width and thickness, but needed cutting to size on the length. Using a saw, cut the wood so that it is 20 mm longer than the phone at the top and bottom.
Step 3: Mark Areas That Need to Be Cut on Wood.
Working on the top of the wood. Using a ruler find the centre of your piece of wood. With a set square, mark a rectangle the size of your phone. The resin channels will run 20 mm from the corner of the rectangle along the shorter side and 25 mm from the corner along the longer side. Mark the position of the channels on the wood in pencil. As the size of the central circle is defined by the size of the drill bit you are using, you don’t have to draw the circle as long as you have the centre marked.
Turn the wood over and find the centre again. The coil needs to be mounted centrally, this is important as the resin on the top will act as a guide to optimise charging. The circuit board needs to be 10 mm from the edge. Place coil, wires and circuit board in position and draw round them to mark the area that will need to be cut out.
Note: make sure the coil is facing towards the top of the wood.
Step 4: Drill Central Circle.
On the top face of the wood, using a 22 mm wide drill bit, drill a circle in the centre to a depth of 5 mm.
Step 5: Cut Channels for Resin.
By clamping the set square in position you can run the palm router along the edge to ensure the channels are positioned correctly. Fix the 12 mm straight router cutter bit into the palm router and cut the 4 corner channels to a depth of 5 mm.
Step 6: Mix Resin.
The resin needs to be in the ratio of 100:45 resin to hardener by weight. I used 10 g of epoxy casting resin to 4.5 g of epoxy hardener giving me a good amount for filling the area. Place a cup on the scales, fill it with 10 g of epoxy casting resin. zero the scales and add 4.5 g of epoxy hardener followed by 1 g of Pearlex pigment powder. This should be mixed slowly with the stirring stick to reduce the bubbles formed. Too many bubbles is one of the main problems with resin casting and this can be reduced by pouring from one pot to another slowly to mix the resin sufficiently.
Step 7: Fill Channels and Central Circle With Resin.
Pour the resin slowly into the channels and circle you’ve cut until it’s flush with the top of the wood.
Note: If your drill bit made a hole through the wood when you drilled out your central circle, you will need to plug this hole before filling with resin. A bit of tape will do the job.
Step 8: Remove Excess Bubbles With Hot Air Gun.
Heating up the resin causes the bubbles to rise to the surface. In order to remove as many bubbles as possible use a heat gun. It's important you start with the gun at a distance from the resin and gradually bring it nearer so that the resin is not forced out of the channels.
Step 9: Let It Cure.
Set aside your wood on a flat secure surface and leave for 24 hours for the resin to cure.Take a break.
Step 10: Cut Underneath for Components.
On the back of the wood start cutting out the spaces for the components. The coil works between 2 mm -10 mm distance from the phone. rout out the circle for the coil in 5 mm increments to the depth of 10 mm. Place the powered coil in position and check if the phone charges. If your phone doesn’t charge, rout down 2 mm each time until it charges.
Rout out the area marked for mounting the circuit board and the connecting wire to a depth of 5 mm so that the mini USB connector is closer to the bottom of the charger. As the change in depth between the position of the coil and the circuit board may put too much strain on the connecting wires, use a chisel to form a ramp in the wire channel.
Step 11: Preliminary Sanding.
Sand the top of the wood to remove excess resin and to flatten the surface with course sand paper grit size 40. The piece of wood I used was slightly uneven so I took the opportunity to sand off the high points on the bottom so that it would sit flat.
Step 12: Rout Top Edge to Give Curved Finish.
Using the palm router and a rounding over bit with a 6.3 mm radius, rout the top edges of the piece of wood to give a rounded finish.
Step 13: Chisel Out the Entrance for Mini USB Connector.
Now the edge routing is completed, cut out the hole for the mini USB connector using a chisel.
Step 14: Finish Sanding and Polishing.
To produce a smooth surface on the charger start sanding with grit size 80 sandpaper and then progress to 600. Polish the resin using 3 step polishing compound to achieve a glass finish.
Step 15: Oil the Wood.
Oil the top and sides of the wood with teak oil. Ideally 3 coats should be applied with a 12 hour gap in between to allow the oil to be adsorbed. Make sure you don’t oil the bottom of the block of wood as the adhesive backing material will not stick.
Step 16: Mount the Components.
Mount the coil in the base of the hole with the coil facing downwards and secure in place with a glue gun. Afterwards position the circuit board in place using small screws.
Step 17: Fix on Adhesive Backing.
Cut a piece of adhesive backing roughly the right size. Make a small tab so that this can be bent back under the mini USB slot to prevent sticking. Attach adhesive backing to the bottom of the wood block and carefully cut to size using a scalpel.
Step 18: Start Charging.
YOU DID IT. good work now plug it in and get that phone powered up.