Indeed, they're similar!

We're going to attempt to weld the second stage pins into place on the drill gearboxes soon, but I'm not sure if that's really the best thing to do. I'd love to keep the 12v motors because the power at the fully charged ~21v is fantastic, I'm just wondering if it's really worth the problem of never knowing how close the setup is to failure.

Looks like moving to 18v motors and 24:1 gearboxes would would cost around 55-60 quid. Has anyone got experience with 24:1 setups? Is the drop in torque particularly marked?

And thanks for the comments guys. Certainly is nippy!

Matt, it should work for all.