pic: sheet metal 6WD

[apalrd]

1. I would recommend a center divider on one side of the motors. It will add strength and also a place to mount an electronics tray (e.g. from the back to the middle with the front open, or something like that)

2. Electronics tray could be perforated aluminum. Just cut it to size, rivet it in, and zip tie the electronics. Nice and easy.

3. I like the chain tensioning method. Super simple. If you want, you could put a 1" tall by 1/4" thick block with a hole for the axle, then tap the end for a 10-24 (or 10-32 if you want) and just tighten the screw to tension it, then tighten the axle bolts to hold everything secure.

4. Are you using servos for the SS's? If you are using pneumatics elsewhere on the robot (or even if you aren't), pneumatics will shift easier then the servos. I do not know how much better they are, but they provide a lot more force to shift then the servo does. We always shift with pneumatics when using AM shifters.

5. Rivets. If you are waterjetting or otherwise CNC'ing the sheet metal plates, just add a few holes per connection and pop rivet it. Easier to assembly, and not much more work in CAD (this is especially true with a pneumatic riveter, those are great)

6. Have you done any math on the speed and gear ratios?

7. .125" seems really really thick. We use something around .050 in our chassis, with a plate around the axles (a little circle with an axle hole and 4 rivet holes, around 1.5" in diameter), or the above mentioned tensioning block with some reinforcement.