Incorporating the vex ball shifter into a WCD Drive

[scottandme]

Originally Posted by jb1403

What are the gears that you are using in the third stage, standard IFI ones? One of the possible issue's I noticed with IFI's third stage is that it sits below the bottom of the plastic housing from the previous two stages, causing an issue if you want to mount the housing to the bottom of a robot with very little clearance. I was thinking about changing up the gear ratio and was wondering if that is what you did.

Edit: above poster beat me to the punch

Look at the part names in the CAD - it's a 34:50 3rd stage. The stock 3rd stage is 24:60. The stock ratio is probably a touch slow for 4" wheels (80% speed loss gives 3.6 and 8.1 ft/s). The 34:50 reduction yields 6.1 and 13.8 ft/s. I don't know why they don't list that possibility on the ballshifter page, but any combination of gears that add to 84 teeth would work. 40:44, 34:50, 24:60 and 20:64 are the only possibilities using vex gears.

You can always cut out your belly plate to accommodate the 60T gear, it will be within the OD of the wheel regardless, so short of sliding perfectly sideways off of a ledge, it's unlikely to contact anything.

The mount Adam posted might interfere a 60T gear, depending on the OD of the standoff some modification of geometry would be necessary.