Ouch Bill! I can only imagine.
I also was surprised about the lack of info on FOPS or forestry cages for small tractors. I guess I searched under "forestry cage" on this site and elseware and came up with very little and nothing for small compact tractors. But then I guess what I'm doing isn't really "forestry". It's more like going into the woods and selectively takeing out dead or diseased trees for fire wood. I rarely drag a log because impacts the forest too much. Instead, I cut them where they lay and can take 1/3 cord out at a time between the FEL and the carry-all. I sometimes use the tractor to push on trees and make them fall where I want when there is no room to run out a rope.
You don't need to do this for too long before you realize that you want some kind of protection.
Here are my thoughts on design and explains why my cage looks like it does:
1. By connecting the ROPS to the front bumper it creates a structural member that takes the stress off the enging/tranny connection when carrying big loads at both ends. Basically it is protection against the tractor cracking in half.
2. By connecting the ROPS to the front bumper it provides protection for the whole tractor from a falling tree rather than just the operator area.
3. The side sheilds are really only to keep branches, prickers and monkey vines from hitting me in the face.
4. The "ramped" design front to rear is to push branches up and over the tractor as you pass by them to hopfully have less of them spring back at you.
5. A grill guard is important because sometimes I lift trees by a chain and they bump against the front of the tractor.
6. Heavy 1/4" thick main rails - I've seen a lot of cages with small tubes which would be great for small stuff falling on you but I often wondered how they would fair if a tree came down on them. I can't answer that for others or myself but I'm from the more it better camp when it comes to these types of things.
What I would do differently - If doing this again I would specify to the builder not to connect the side shields to the fenders and instead connect it to the lower portion of the factory ROPS. My drawings showed both, but then I went over budget before he connected the cage to the ROPS. I think the 4 point connection to the ROPS would be a lot stiffer than the current 2 point connection, and would also help keep the cage from racking in a roll because it couldn't slide on the 2 point clamp. Of course, if money allows I would add 2 extra side supports.
Have fun with your FOPS build. Can't wait to see what you come up with!
My 
