On The Bench 189: Dave Ruther’s Firefly

Here is a brief On The Bench Update with more of Dave Ruther’s Firefly project!

My model building experiences come in two types. There are the models that I start with the best intentions, but never finish. Or there are the models that I start with sheer determination and it becomes almost an obsession to get them finished! I think this model has come under the latter, as no sooner had the sanding dust settled, I was off again…

First job was to get the wheels finished. When I built the ‘idler’ wheels, I made a mould using latex. Smashing stuff, but for one obstacle – it takes ages to set and to get a good mould, you need to apply it in layers. The bottom line is it takes about a week to make a decent mould. I didn’t fancy splashing out on RTV rubber, so used something that all you dentists should be familiar with – Alginate. This is a blue powder that when mixed with water forms a smooth paste. It’s used by dentists to take moulds of your teeth! The good thing (or bad thing if you aren’t quick about it) is that it sets in around 3 minutes! I built a master of the drive wheel, again using panel pins fitted through drilled holes for the rivets. A plastic card wall was built up around the wheel and the alginate was mixed up and poured in:

One of the problems with alginate is that the moulds only last for about a day, as they dry up, shrink and go brittle. Therefore, it was a case of pour the resin in, pace around the garden, tip out the cured wheel and start again.

Only four wheel halves were needed, so this didn’t take too long.

Whilst the wheels were drying completely, I added the dry transfer ‘Firefly’ words down the sides of the main model and added the black stripes.


The cowl underneath the vehicle was cut from balsa and covered in automotive filler. A very important lesson, which I learnt from reading David Merriman’s excellent article on the ‘Dove’, was to put tape over the model and then use automotive filler to get the correct contour of the part you’re fitting. Thanks David that was invaluable! This way, I was able to build and paint the part separately, without having to blend in gaps and end up re-spraying the model! This cowl was fitted with a grill and glued underneath the cabin.

The wheel halves were then glued together and fitted to the brass axel. The track was cut to the correct length and glued back together over the wheels. Plastic tube was fitted over the axels to prevent them from moving from side to side

The drive wheels were wrapped in a thinner piece of cam belt, which locked into the ‘teeth’ of the cam belt on the inside of the track. What’s more, the suspension worked a treat!

More to come



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