05-2009
The T-72's turret is all curves. Building it from wood, or even fiberglass on a wood frame, is probably not going to work. I considered both a vacuformed plastic turret (as on my Tiger), and a fiberglass one. I wanted to get some experience using fiberglass, so I decided to go that route.
The first thing I needed was a 'plug'. That's just a model of the turret shape I wanted to build. I have a 1/35th scale Tamiya model of the T-72 but I don't have the artistic skills to translate that right to a 2/15th scale plug. So, I used a form of the technique generally known as 'lofting'. I started out with a software 3d model of a T-72. Using Google Sketchup, I cut horizontal cross-sections of the turret at regular intervals. I took about 12 layers. That gave me a series of 12 oval shapes. I transferred each oval to a piece of scrap 3/8" plywood. That would give me the correct turret height in 2:15 scale. I added an extra 1/2" layer on the bottom to act as a riser (and give me a little cheat room). Each layer had registration holes to make sure it was in the correct place in relation to the adjacent layers.
After I cut and drilled each layer, I glued them together. I ran long bolts through the registration holes to act as clamp. After the glue had set, I started the long task of sanding the stairstep edges smooth. I used a belt sander with 36 grit belts, but it sill took forever. I filled any gaps and added contours with plastic wood. Then, I sanded some more with a finish sander. I used the Tamiya model to eyeball the turret shape as I went. Finally, I had my plug !