Step 9: The power cell
To form the basic cardboard shape find another object with roughly the right diameter (80mm), I used a plastic drinks bottle. Wrap the first a sheet of cardboard (A4) around the bottle and use some masking tape to hold it in place. Don't worry that the card doesn't wrap all the way around the bottle, the gap will be placed against the stock so it won't be visible. Once the first piece of card is stuck down you have something to glue onto. Smear a second sheet of card with a good covering of the PVA and water mix and wrap it around the first. Repeat this until you have 4 layers of card on the bottle and the card starts to hold it's own shape.
At this stage you need to make a second cylinder a little larger than the first. Wrap the next layer of card around the previous cylinder but this time don't glue it, hold it in place with some more masking tape. Build up another 4 layers on top of this one and wait for it all to dry. Once dry you can take the tube off the bottle former and seperate the 2 layers. Cut the bottom layer to the desired length and the top layer 30mm shorter.
Once the layers are seperated you can begin to carve some detail into the top layer. Draw the desired shapes on a flat piece of paper and then cut them out. To make four arrow shapes of identical sizes, draw one shape and cut it out, trace round this shape for the next 3 shapes and then cut those out too. Wrap the paper around the cyclinder and trace through the holes onto the card. Using a scalpel, carefully cut the shapes out of the card, being careful not to slice through your fingers.
To make the power cell end caps, first draw some circles of the correct size into the foam using a compass. Roughly cut the foam out of the block as a square shape. Carefully cut down to the line using a stanley knife to make lots of straight cuts until you have an octogon with the circle inside it. The cut the corners of the octogon down to the line, repeating until you get a roughly round shape. Sand the foam into a smooth circle. At this stage, cut the flat spot on the caps so that it sits against the stock.
To taper the end caps draw a line around the caps, 10mm from the end for one and 30mm from the end for the other. Hold the stanley knife at the desired angle (roughly 45 degrees) and cut from the line down through the cap. Turn the cap around 90 degrees and cut again, repeat until 4 cuts have been made, then cut those corners off, repeat as before until the shape is roughly circular, then sand the suface smooth.