So after trying to salvage what I could from the helix project, I managed to get all the track pretty level making a smooth climb through the levels. It was useable to change levels, almost...
Only two of my Kato engines could make climb. Everything else stalled and wheel slipped. Even two engines of low traction had trouble sometimes.
So in the end, I think the grade is gonna be the killer on the helix project. While I could make a helix (even if built 100% perfect) work, I'm not sure I want to put that constant strain on the engines and rolling stock.
So, now what? Well. I'm thinking a lift/elevator. I'm thinking of using an RV scissor jack with a 15"x36" piece of 1/4" plywood attached to the top. A train will have to go onto the platform in a curve inside the alcove. The jack is able to raise up 24", so it's got plenty of room there (only need 17").
Then just attach a motor, and voila, motorized elevator.
While it's not the most ideal way to change levels, it might be my only way (unless a I drill a hole in the wall and run a train to the garage to a helix. But I think the wife would kill me.)