Hello, I'm the other construction of this project ...
if I understand it you want to know what kind of railsystem we used:
for traction as he mentioned my friend THE CURE is a drive system with
toothed belts with a double reduction ratio, which allows us to have a rotation (at max speed) to 72 degrees per sec.

2013-07-29_17-03-05_380.jpg (1.49 MiB) Viewed 3769 times
- Traction
We wanted to use those Vulkollan but were too hard and slippery so ...
so now the whole structure is moving on polyurethane wheels with cast iron center (those of traspallet to speak, because they are dimensionally stable even if they remain still for a long time in the same position) .... one of which we have modified to insert ourselves traction;
an example for sampling can be found here ...
http://www.tellurerota.com/en/product-rangeOn the other hand though, if you want to put the engine in the middle you should use the wheels from sliding gate, costuire a circular track and appoggiarcele above ... (the only flaw is that they are intemante metal, so there may arise some noise)
If you want to take example, some video here could be for you ...
you do not see so well but I think it is sufficient to
http://www.youtube.com/watch?v=U82iHzs2 ... iUwAZyLEioI hope I was helpful .... greetings and news updates soon ... stay tuned
BASTHARD
