I couldn’t find a ball with radius I needed so I had to make my mould from scratch. First of all I cut cardboard arches with necessary radius smaller by 5mm. I only needed to make a section of the sphere. This was my quite rigid construction. I stuck few layers of paper (I used old newspaper and PVA glue) on cardboard frame to make a surface. Then I Added 5mm layer of air drying clay. When it was hard, I sanded it to get the smooth surface. I often checked it with stencil to check the curvature. After few hours I was happy with my mould.
Then I prepared 2 timber frames and many paper clips. I placed sheet of styrene between them and joined with paper clips. Frames need to be rigid enough to hold melted styrene in place when pushed against the mould. Put it for few minutes to the oven. I watched closely if its getting soft. I took it out the oven and quickly pressed on mould. Always use gloves at this stage !!! It hardened in few seconds and it will kept the shape. I needed 2 copies for each wall.
My walls are thicker than styrene I could buy in my hobby shop. I needed to add this thickness. I cut the rough shape of the wall and stuck it on my mould with 2 sided tape. That will be bottom surface of my wall. I glued few narrow stripes of styrene on the perimeter and few in the middle, creating sort of mesh. I glued another layer of thermoformed styrene on top of it. I cut it to the right shape and sanded edges. This way I had thick wall with smooth surfaces on both sides. I had to repeat the process 3 times.
It was very time consuming process. Now I would rather use rapid prototyping technology. It would be much faster and precise. The shells would be 3d printed from plastic material with exact shape and dimensions as in 3d software.
The cost of desktop rapid prototyping machine is dropping and getting more affordable. That’s why many 3d printing services are available for hobbyists. The one I tested myself is Shapeways.com . They have several rapid prototyping printers in their machine shop and their growing design community is very helpful to explain the techniques of creating perfect, non-manifold model. With shape like this It would be very easy to create it in blender and 3d print it. Easy and clean way.
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Here you have few photos of my weekend project. I prepared my drawings a while ago, and decided to cut it now. It is my new master for resin casting. Its made of cardboard, bricks and some war damage is engraved on surface. I will patch few places with putty, add more cracks and texture to plaster, add some details like broken glass, timber joists and a little plush teddy bear on the floor
Then I will sand it in some places, prime it and its ready for silicone mould. Anybody wants one?
Its all laser cut from 1.5mm and 0.5mm cardboard. Bricks are made in two passes : first is engraving for about 0.4mm deep, then mortar line is cut for another 0.4mm. Floors are cut from one 1.5mm cardboard (the shape with joists) than on top of it is a 0.5mm paper layer with timber boards. Bottom side is again timber boards and another layer with peeling plaster ceiling.
Buy Flames of War terrain here.
This is the project I am working at the moment. It is Saint Bartholomew Church on the Clyde Road located in Balsbridge in Dublin. When I first saw this building few months ago, something captured my attention. Was it the location? Its stands on the triangular land surrounded by red brick houses converted to embassies. Hard to believe that when it was built in 1867 it was open fields.
The church was designed by an English architect, Thomas Henry Wyatt in a Gothic Revival for Sidney Herbert, of the Earls of Pembroke. The original design was never completed, the unusual octagonal tower never received its intended spire.
I am building the laser cut cardboard master in scale 1:160 (N scale). I am going to make moulds of finished pieces and cast it in resin. Buy N-scale buildings on Ebay here.