Coin Radio: Hacking a Radio

 Coin Radio is a fun and exciting radio designed for children.  It is designed as a novelty way of interacting with the radio compared to the traditional radio design. The child will insert a coin into the top of the radio and watch the coin descend down to the bottom. When reaching the bottom the coin will turn the radio on.

                                                            
                
                                                           VIEW VIDEO BELOW TO SEE RADIO WORKING
                                                                                                    

Part Number            Part title                                        Material                Process                     Quantity
1                              220x5mm side                              Acrylic plastic        Laser cut                        4 
2                               220x180mm front middle back    Acrylic plastic        Bandsaw                     3
3                               120x5mm slats                             Acrylic plastic        Laser cut                        4
4                               207x107mm top and bottom         Plywood                 Bandsaw                    2
5                               handle                                            Plywood                 Bandsaw                       1
6                               Grill                                                 Plywood                 Laser cut                        1
7                               scoop                                               Plywood           craft knife and glue          1
8                               Battery box with 2x1.5v batteries   -----------            --------------                      1
9                               107x50mm sides                           Plywood                 Bandsaw                     1
10                              220x50 front and back                  plywood            Bandsaw                        2
11                              6mm rods                                       plywood            Bandsaw                         2
12                              Dials                                                  metallic            Bought                            2
13                              140x5mm                                         Acrylic plastic      Laser cut                   1
14                               Speaker                                       --------------              ------------                     1

We started this project by being given a small portable sony radio. Simply taking the back and front off it left us with the circuit board speakers and ariel. For power it is easier to buy a small battery box suitbale to hold two 1.5Volt batteries. 

at this stage the circuit board should be fully detached from the original plastic casing. The next thing that should be done is attaching a micro switch between the battery box and the circuit to act as a switch when the coin hits it. when the coin hits the switch it will have to land in a bucket of some sorts so add a small shaped scoop onto the end on the micro controller switch for the coin to rest in.
When the coin lands on the scoop it will switch on the micro switch and in turn will complete the circuit and the radio will play. 
 

For cutting out the wood for the base of the radio cut out the measurements bellow (measurements are in mm)

2X   (220x50) front and back

2X   (107x50) sides 

2X   (207x107) top and bottom

in one of the 220x50 cut out a rectangle (97x38) on the left hand side. this will now be the front

on one of the (207x107) cut 2 circles 6mm and 30 mm apart and create a slit on the left hand side of the wood big enough for a coin to fit through. This will now be the top

for the plastic on the top cut out. use clear acrylic plastic but the thickness does not matter. Mine was 5mm

3X (220x180) front middle and back 

4X (220x5)  sides

4x (120x5)  slats for coin to roll down 

1 x (150x 5) for the top between front and middle.

I used a laser cutter to cut out the shapes as it gave a smooth edge and precise cut but a band saw works just as well.  

For the grill for the front of the radio cut a piece of thin plywood (100x 40) and cut holes into it as well for the sound to exit. 

I cut mine on the laser cutter for a precise finish. 

insert as many holes as you wish and what ever shapes you wish. 

this grill should now cover the  hole created in the wooden box 

For this part of the process glue the 220x 5 onto  the left hand side of the 220x180 the other 220x5 onto the right. as an extra cut out a small semi circle in the top of the 220x5.

do the same again bar cutting the semi circle

then glue the two together. then on the front add the four 120 x 5 at angle so that the coin can roll down.  

Add the 150x5 to the top. then finish of by potting the last 220x180 on top to enclose it all.  

gluing the wooden box together. Glue the top front and back and the right side at this stage. 

the other side will have to be left off till you fit a handle and the bottom cant be fitted till the circuit board is added to it. 

using a flame i melted the plastic down on the edges to smooth off the edges.

glue the two together so that they fit securely and make sure the coin will drop down the hole. 

attach the circuit board to the to the top of the bottom piece of wood and slide up. attach 2 rods coming up from the volume and the tuning to act as dial. 

add any dials you wish and create a lever for the side to open so you can remove the coin in turn turning the radio off.

Radio should now be complete 

Enjoy !