Introduction: Decoradio: Hacking a Radio for Painters and Decorators
This is our second year Product Design assignment which lasted 12 weeks at Dundee University. Our aim was to create a fully functioning radio to suit a particular user/client.
For my project I chose to design and build a radio to suit a painter and decorator in his working environment. The radio had to be able to withstand paint splatters and be at a suitable height so that the client does not have to bend down in order to operate the design.
I have named my design 'Decoradio' and the next few pages will show exactly how I managed to construct my design.
Step 1: Exploded View and Components Manufacturing List
Materials needed:
140 x 110 x 12mm of MDF X5 - Front and back of radio
60 x 60 x 12mm MDF X3 - Very back of radio
80 x 125 x 12mm MDF X2 - Base
50 x 65 x 12mm MDF X 4 - Volume
150 x 80 x 12mm MDF X 3 - Roof (AM/FM switch)
70 x 80 x 10mm MDF X 1 - Very front of radio
60 x 60 x 5mm MDF X 1 - Speaker cover
55 x 55 x 10mm MDF X 1 - Tuning dial
35 x 20 x 12mm MDF X 1 - AM/FM switch holder
Sanding Sealer
x1 Suction Cup (Sat Nav suction cups work extremely well for this project)
x1 ICF - S22 radio
Radius: 1.5mm Length: 20mm steel rod
Radius: 2mm Length: 300mm Aluminium tube
Wood Glue (PVC Glue)
Super Glue
Primer
plasti-kote SUPER Gloss paint x2 (colour dependent on base and body you require)
Tools/Equipment required:
Precision Screwdrivers
Band Saw
Pillar Drill
Sanding Machine
Hand Sander
Metal Hand Saw
Coping Saw
Hand drill
Chisel
4 ounce hammer
Selection of wood files
Variety of Sandpapers (80 to 240 grade)
Ruler
Pencil
Compass
Glue Gun
Soldering iron
Solder
Multi core wire
Here is an exploded view of Decoredio to show the components required.
Step 2: The Circuit
The circuit used has been taken and modified from a previous, basic radio. It's worth pulling apart the radio carefully with precision screwdrivers to separate the interior from the exterior. When the circuits been pulled out of the old radio, scrap the body and check to see if the circuit still functions properly. It's best to leave the circuit modifying until the end as it will have to be assembled around the new radio body that is to be created.
Here are some photo's of my radio at this stage:
Step 3: Step 1: Creating the Front and Back (part 1) Shells of the Radio
This is where the 140x110x12mm MDF is required. You will need all of these pieces. The front and back do not require any hollowing out so the first picture is what both the front and back should look like. I'd remove the bottom legs though as this will make the frame is easier to build later.
The second picture is what the other 3 pieces of MDF should look like. Again I'd remove the bottom legs so the frame can be built more accurately later. Once hollowed out, glue all 3 pieces together. When dried and stuck together, sand the inside so that all 3 pieces line up accurately.
Picture 3 shows the front of the radio when fully shaped. Using the pillar drill drill, a hole with a radius of 27.5mm in the centre of the radio front. Using the 70x80x10mm MDF draw a circle with a radius of 27.5 in the centre and another of 35mm about the same origin. At the top and bottom of the outer circle carefully hand draw the ring shape. When this is done, use the sanding machine to create the outer ring shape. hand sand the whole ring down so that it is very smooth though allow the top of the ring to stick out more than the rest. Glue to the front of the radio.
When dry use the pillar machine to remove the smaller hole. The hole will go through the front face of the radio as well which is where the speaker will be. Ignore the base on the picture as this will be covered in the next step.
The back face of the radio requires a hole with a radius of 15mm in it's centre.
When all these steps are done glue the back of the front to the hollowed parts and the front of the back to the other side of the hollowed parts. The radio should look like picture 5 when finished except without the base.
Step 4: Step 2: Creating the Base
This shape is much easier to achieve than it looks. Look at the second picture and imagine the top left to top right to bottom right as one 'L' shape and the top left, bottom left to bottom right as another 'L' shape.
Using one of the 80x125x12mm MDF cut out these two 'L' shapes and place them together to create the rectangle. Now put the radio shell into this rectangle and adjust until there is no clear gap between the radio and the base. Take the radio shell out and glue the two 'L's together onto the other 125x80x12mm. When dry, hand sand the rectangle to create the curved edge right the way around the base.
Glue to radio shell, this should be a tight fit with no gaps showing.
Step 5: Step 3: the Back (part 2) Shell of the Radio
This is the box which sits on the very back of the radio.
To start, glue two of the 60x60x12mm MDF together then drill a hole with a radius of 15mm right through the centre of this using the pillar drill. Glue this to the other 60x60x12mm. Drill a hole through the top of one of the sides with a radius of 2mm in the sides centre. This will go right through to the hole created by the pillar drill. The aerial will slot into this hole so this side should be facing upwards when attached to the back of the radio.
Sand all corners with the hand sander to create the curved edges.
Using a chisel and the 4 ounce hammer create a slot large enough for the suction cup to fit into place. I'd create the slot slightly larger than the suction cups joining area as the radio will be spray painted later. By doing this the joint will shrink slightly due to the build up of primer and gloss paint making the joint tighter. Stick to the back when done. The suction is detachable so that when it isn't hanging from a window, it can be placed on a shelf with it's back right up against the wall if needed.
Step 6: Step 4: the Roof/shield
This is one of the harder shapes to create as a lot of hand crafting is required.
Start by gluing the three 150x80x12mm blocks of MDF together on top of one another. Draw the desired curve in pencil on the long side of the block and remove the unwanted MDF using the band saw and the sanding machine. The result of this is the first picture below.
This is the most time consuming part of the radio. Using wood files and a curved sanding machine remove all the unwanted MDF until you are left with the complete curved shape of the roof. Draw on the roof shape and cut out using the band saw.
Sand down all surfaces until you are left with a completely smooth curved roof.
The third picture is the small piece which will hold the AM/FM switch and connect the roof to the radio. The 35x20x12 MDF is needed for this. Simply drill a hole with a radius of 2mm at a slight angle through the small block using a hand drill. Then hand sand the entire block until you have the shape below. A rough sand paper is required for this.
Picture 4 shows the other side. A pocket has to be created for the switch so clamp down the block and carefully chisel just enough MDF away for the AM/FM switch to sit comfortably in.
Step 7: Step 5: the Aerial
The aerial is a hollow piece of extruded aluminium which is perfect to allow wires to run up inside it. All that is really required is to remove 30mm from one end of the 300mm tube for the roof to connect to the radio top. The longer piece simply needs to be bent around a curved surface to create the hook shape. This will be so that the radio can hang, like a coat hanger, from a ladder when in use.
I used a glass as my curve to bend the tube. Make sure this is done carefully though and slowly so as to not buckle the aluminium.
Step 8: Step 6: the Volume Dial
Use the 50x65x12 MDF for this. Stick two of these together and drill a hole with a radius of 17.5mm in the centre. Glue the other two 50x65x12 on either side of the other two already glued together to hide the hole. Keep hand sanding the sides until you have a nice rounded shape. Saw straight through this half way as done in the second picture below.
Choose one of these two pieces and drill a hole with a radius of 2mm so that the aluminium tube can slot into place.
Step 9: Step 7: the Pins
Three pins are required to put the radio together. Use a metal hand saw to saw through the steel rod to create three pins each of 2cm in length. File one of the ends of all three pins so they are slightly pointy. The points will later help directly connect the front and the back of the radio together.
You need to gain access to the inside of the radio. Cut through the entire radio down it's side as done in the picture below. Drill three small holes for the pins to slot into place so that the front and the back of the radio can piece together.
A hole needs to appear on the top curve of the radio. This is for the roof to slot into place. So, half way down drill a 2mm radius hole for the aluminium tube.
Down the taller side of the back of the radio, cut out a groove as done in the second photograph. This will later be for the tuner dial to slip in place.
Step 10: Step 8: the Speaker Cover and Tuning Dial
Cut a circle out of the 60x60x5mm MDF: radius of 27.5mm and draw in pencil two lines which travel through it's origin and quarter the circle. Then draw two more lines that also travel through the circles origin to split the circle into eight equal pieces.
Using a very small drill tip, drill through the origin. then equally measure for four more holes to be made vertically and horizontally. For the other two lines only do three holes with equal spacing. Make sure all the holes are of equal size.
For the tuning dial, cut out a circle with a radius of 2.6mm out of the 55x55x10mm MDF.
Step 11: Step 9: Applying the Primer Coat
All the pieces have been created. Make sure that every piece has been sanded so it's as smooth as possible. Then apply sanding sealer to all MDF pieces. When this is done, spray painting can begin.
Spray the front shell, the back shell, the roof, the volume dial, the tuning dial, the AM/FM pocket and the speaker cover with a thin coat of primer. When this is done, turn the pieces over and do the same again. You should wait a minimum of 10 minutes between each coat but I waited 20 before I even touched the pieces just to be sure they were dry.
This should hide any joints that have been created by gluing the wood together to make it look like one whole shape. Apply at least two thin layers and hold the spray a suitable distance away from the radio to prevent creating 'puddles' on the work.
I've assembled the pieces together with blue-tac to see what the final piece will look like.
Step 12: Step 10: Applying the Gloss Finishes
Spray all the pieces with the desired gloss colour finish. For me this was dark blue all over. There is a lot of patience needed at this point for you have to wait four hours between coats. Put two layers on each piece and wait until dry.
When this is done, cover any parts that you wish to paint another colour with masking tape. Spray any other parts that need to be sprayed with another colour and leave to dry.
This is what the radio shell should look like after the finishes have been applied and pieced together.
Step 13: Step 11: the Wiring
This is the fiddly bit. Unsolder all components one by one that need to be detached from the circuit board. Make sure you know exactly which piece goes where on the circuit board that you are about to pull apart before you begin. This is mostly increasing the length of the wires such as in the volume dial.
Tip: Colour both ends of each wires or use different coloured wires so that you know which wire is to connect to which part of the circuit. There are five wires that have been fed up the tube aerial so it is important to not get confused which wire is which.
Remove both the original tuning and volume dial. Add the new tuning dial that has been made and glue in place with super glue. Make sure it can still turn easily.
Replace the battery pack with another smaller version so it can fit better inside the radio shell.
Step 14: Step 12: Assembly
The radio is just about finished. Glue the pins with super glue into one side of the radio so they are sure not to fall out. Using a glue gun fill the AM/FM pocket to prevent it from moving around. make a small hole in the roof of the radio and connect this to the AM/FM switch. Now the roof is the AM/FM switch.
Glue the speaker cover in place and make sure there's enough room for the speaker to sit no more than 5mm behind. Glue the circuit board into place though make sure this does not prevent the tuner from turning easily.
Pop the batteries into place and squeeze all the components inside. this will be a very tight squeeze though should all fit in place.
Turn the volume dial to turn on and tune in to your favourite radio channel!
