After I helped out at the Monsanto event with the pro-evangelists, I was talking with one of their engineers and he told me about a few different solutions for my chain looseness issue.

McMaster-Carr has a few solutions, each has pro’s and con’s in terms of space and cost.

Floating Roller Chain	Pro’s: $33 each Adjustable Would be perfect for the first gear set Cons’s: While 1.1” thick, .25 has to be sticking out on each side 2.5” long, the gap between gears is about that. No clearance on the chain with the wheel
Vertical-Mount — Manually adjustable	Pro’s: $48  each Could possibly fit this in from the other side 1.375” thick Cons’s: Still requires a gear Tad expensive Requires a gear Have to modify the gear box so chain doesn’t rub
Automatic Spring Roller Chain	Pro’s: hmmm Cons’s: Big, 5” tall Tad expensive @ $53
Low-Profile Automatic Spring Roller Chain	Pro’s: .5” thick. Cons’s: $77 each

Lets show the gear box to see some of the issues I’m talking about

The gap is VERY narrow between gears, about an inch.  Also the width is 2.5”.  The wheel and big middle gear have under .25” of clearance between one another.  I would have to modify the structural supports to fit in something to the middle

I could remove the middle gear set, and then use a Vertical-Mount Tensioners or a Floating Roller Chain to accomplish this.  I’d have to cut a big hole to use the floater.  The vertical-mount tensioner I can just create a platform and extended it from the other side and either provide tension from the inside of the chain or the outside.

I could use the Automatic Spring Roller Chain too and have it mounted from the outside on a ridge mount.

No matter what, I think a phone call to my dad is in order along with a trip back to Chicago so he can help me install a solution.