Screw driver, limited torque

thingiverse

Could not resist to buy some awesome [Battat take-apart](http://www.battatco.com/collections/battat/take-apart-crane-truck) toys (2nd edition). Since the plastic threads used, is about 3/4th of rotation, it's a little delicate. That's why the provided screw machine is relative weak. So there should be a torque limited screw driver applied together with the nice collection of AndrewBougie magnet-remixe-bits, or just use this screw driver with the original bits. The screw driver is torque limited: * spring loaded (pre tension could be tuned) * could add up to 6x steel balls (3 seems enough) * torque limit is (almost) independent on how hard the toddler will press the driver into the bolt * by design, maximum tightening torque is a bit lower the loosening torque * only 3 printed parts are needed, when using the standard Battat bits (choose option A) * or use the nice bits from AndrewBougie / remixed magnetic version (choose option B) Use these Battat compatible [bolt & nuts](https://www.thingiverse.com/thing:3329568) for replacement parts and download the alternative designs.