TIPS AND COMMENTS
This is an expensive project, so you want to scope everything out before you commit.
Plan your height so you can still mow and it won't be at eye level for family.
I couldn't install a trolley the entire length of the fence because the yard slopes at one end. The ground needs to be pretty level.
I do not know how this would work for a larger dog. There is probably a limit to how much weight the track can carry while attached to unstable chainlink. This works for a 9-lb dog. If you have a heavier dog you might have better luck installing on a wood privacy fence.
Some chainlink fences have the chainlink stretched tighter on the fenceposts than others. If your chainlink bows out and doesn't look flat, that may need to be fixed before you install a trolley.
You'll notice in one photo there is a slight curve on one of the joints in the track. It is not noticeable when we use it. Any vertical misalignment is noticeable, but you can't tell the slight horizontal deviation is there.
I first tried less expensive shelf brackets. They were 15" but the screw holes were small and I didn't like using wimpy screws. Reaming out the screw holes would probably weaken the bracket so I got heavy duty brackets with bigger screw holes so I could use stronger screws. Below is a picture of the kind that
didn't work.
One consideration is how far your dog will be out away from the fence. I used 15" x 13" brackets for my small dog. The end of the bracket was 13" out from the fence. But the screw hole is not at the very end of the bracket so there is really only about 12" from the fence to the center of the trolley track. In addition, the posts are on the inside of the fence, so he loses another 1.5" of shoulder room every time he runs past a post. I think you'd want to be sure your dog isn't going to be brushing against the fenceposts if he is a bigger (wider) dog. A dog with weak front legs has more trouble steering, so clearance on the side is important to a quadriplegic or front paralyzed dog that can't steer as well. He may not go quite straight, or be able to course correct quickly.
If you have a problem losing the screw (it falls down inside the track) while attaching the track to the bracket, it is hard to get the screw re-inserted through the hole. I had to disconnect one of the connectors to get a screw re-inserted, and almost had to take the whole thing off the fence again. Using 1.5-IN screws instead of 1-IN would probably be easier to work with if you have big hands, because it will give you more to grasp. You would need to decide whether you want 1.5-IN screws when you are putting the 6 pieces together at the beginning. Once it is together, you can't get a different screw in there if you want to change to a different size, because the width of the opening on the bottom of the track is not big enough to pass the head of the screw through even if you angle it.
When I made it, I didn't know if the track would stay smooth or if parts would loosen and get out of alignment. We've been using it for over a week and haven't noticed any problem. Temperature change hasn't affected it either. If I notice anything, I'll post a follow-up. So far so good, and he likes it.
You may wonder, why not just get him a quad cart. He has one, a nice one, but he can't run in it like he can on the trolley. He loves running!