Skirt Body 

As this is a very low budget build, I made the skirt from some rigid cardboard I found.

I wouldn't recommend buidling Daleks using cardboard, it's quick, but the finished result isn't too smart.

It easily picks up creases, scratches, punctures, dents, and crumples if you're not careful.
As it's quite a weak material, it also won't stand up to much punishment in service, especially when a three year old is unleashed on it!

The skirt body was the first part of this project that I made. The rough shape took one evening, and was rolled together out of one piece of cardboard, plus a top and a bottom.

When I applied the folds, wrapped it round, and stood it up for the first time, it was quite a magical moment to see an instantly recognisable shape come together in front of your eyes!

The material shown here is an old sign from a care home. It's made form a material called Alupanel, manufactured by Perspex. It's a polyethylene and aluminium sandwich composite material. I used it for the top of the skirt to give a solid surface to mount the shoulders, and also for the top of the fender.

Making a DIY Vacuum Former

There are a few main components to a vacuum former / vacuum forming machine:

• Mould - this is what the plastic forms around
• Platen - this is what the mould sits on, and air passes through
• Frame - the frame supports the plastic when saggy, and seals to the platen
• Vacuum Pump - I used a Numatic Henry vacuum cleaner

I made a box as the basis of the vacuum former, deep enough to allow me to connect the vacuum cleaner's pipe.

The plastic needs a support frame for two reasons:
1. To support it when hot and carried onto the former.
2. To provide something to stretch against, this reduces webbing when the vacuum is applied.

I designed the size of the circular cutout in the support frame to be twice the size of the component. Luckily my cafetiere was 100mm diameter, perfect for marking out since I didn't have a pair of compasses! The support frame is held together with bulldog clips. Also note the handle integrated into the frame, this was very useful.

Making the hemispherical mould.

The hemispheres are 50mm diameter for this half scale Dalek.. but finding something to mould the plastic around that was slightly less than 50mm diameter (to cater for the plastic thickness) was a bit of a challenge.

So I ended up using a spare 50mm wooden ball (same batch as the eye ball and plunger arm / gun pivots). As this will result in a hemi slightly over 50mm, when I cut the wooden ball down to make it a hemisphere, I purposefully went off centre to 48mm to make them appear slightly smaller, even though the radius was slightly over.

I added a 3mm MDF spacer to the mould to lift the hemispheere up from the platen, to eliminate any radius from the final item.

I used some car body filler to make good of any imperfections, then drilled holes in the platten to allow the air to be evacuated to the box below.

Trimming the wood to suit the size of the bulldog clips.

In trial fitting the platten, I made a schoolboy error with a screw position, but it was soon rectified.

The platten was sealed to the box using some foam draught excluder.

Platten fitted, two alignment guides installed, and getting set up with Henry Hoover.

Plastic sheet cut into squares, and into the oven. This particular polystyrene plastic sheet does a strange thing as it heats up, it sags, then pulls tight again. I found that baking it at around 230°C / Gas Mark 8 worked best, but still not brilliant.

Initially I'd tried 170°C / Gas Mark 3 which took a long to become soft, during which time bubbles formed in the plastic - but going hotter for a shorter time produced better results, but still not perfect.

The bubbles are caused by moisure in the plastic boiling off. This is fixed by warming the plastic in an oven at a lower temperature for a long time to bake out the moisure, then quickly heating it ready for forming.. My plastic had come straight from a cold damp garage.

Forming the hemispheres was great to see, they pulled down within seconds, and cooled quickly back to solid. However, the bubbles are clearly evident in this hemisphere:

I've formed a handful so far, but still have to figure out a way of trimming off the excess plastic, leaving a perfect / flat edge.

Once trimmed, I plan to fill them with builders expanding foam, which will give me a surface to glue them to the skirt panels.

I'll soon be using an adaption of this vacuum former to make the Dome Lights too.