I tried to send you a follow up file and the email kicked back for some reason. I finally just deleted the frame rail that was driving me nuts and cloned the other one. Just to make sure the frames were lining up I used 3l pins and a 1x3 plate between the front of the frame rails to verify spacing.
I grabbed a regular gear to try, but I like your double bevel gear idea too. I found that a large motor combined with a worm gear will mesh with 24 tooth gear, and be lined up axially and vertically. This is all practice at this point, trying to work out a reasonable plan in digital form. Everything is up for discussion. It may actually make more sense to have the motor over the drivers and use the offset space to gear up to gain some speed.
Looks like a worm drive to an axle mounted gear will work in general, which is great.
the image below is a render from the stud.io software, which is a pretty cool feature.
