[Boltman]

To summarize and to try to help..for your bot (as for best guess from your picture)

Each front corner will need an 8" bumper side. In other words, The front of your bot will have to have 16" of bumpers with 8" per corner.

The issue you will run into based on what I see, is that the shooter will very likely, hit the bumper as it raises and lowers. So take that into account as I don't see it working as configured in pic. You may have to make your bot wider (or add 4"+ mounting extensions on side) to avoid the shooter hitting your front bumper or you may have to move your shooter forward so wheels are past the front bumper up to 15" forward of frame perimeter.

There is no way around the 8" per corner of bumper in your case based on what I see.

Hope that helps.