I've seen on YouTube some videos of full size, metal gear servos, rated 32kg/cm pulling 4 full crates of Coca Cola. As I remember, each crate had 3x4 bottles of 2 l Coca Cola. So if you want to put a DSLR onto it, go for one of those. There are few around. You can buy some aluminum sheet, say 1mm thick, on eBay and cut and bend it into strong brackets.
A bit of trial and error.