Thank you very much....:goodpost:add some more slack to the knott side of the slip knott. sure as you pull on it t gets tighter, but id does so ono both sides. we use slip knotts for wire pulling and if there isnt enough meat on the slip side it will fail. just double check the total travel of the spring and add some slack to the "safe line" if the safe line is shorter to that of the spring travel your dog will not get the full effect of the work out but it will also transfer the the actual foundation of what it is lashed to.
i think the overall look of the set up is terriffic
The spring is from a boat, used to tie them down...check the lb/sq in that spring is, just to make sure the game is competative and not a one sided workout. no one likes going into a game knowing that its futile. test springs and see how it travels with the strength your dog is applying. if the spring is too big your dog will not benifit from the actual game. if its noo weak it could snap and hurt something/someone