BAG motor shaft that fits in a VP gearbox?

[pkmn25]

So, for our gatherer, we're using a BAG motor and two 10:1 ratio VersaPlanetary gearboxes. We've found the correct mount for the motor to the gearbox, but the shaft on the BAG motor is waaaay too small to fit into the gearbox. Does anyone have an idea on if and/or where we could find a shaft that fits onto the shaft of the BAG motor so we could use the VersaPlanetary gearbox? Any feedback is appreciated!

FYI: the BAG motor's shaft is 0.157" in diameter and the hole on the gearbox it needs to fit in is 0.313" in diameter.

Thanks for your help!