How to make a hand drill from the gearbox of a broken grinder

The gearbox from a burnt grinder can be used to make a hand drill. This tool is useful for drilling wood, plastic and soft metals. Although it is not as productive as an electric drill, it is silent and autonomous.

Materials:

Broken grinder;
bolt M12;
drill chuck;
a handle from a meat grinder or a connecting rod from a children's bicycle.

The process of making a drill from a grinder gearbox

You need to unscrew the gearbox from the grinder body and remove it. Next, the rotor is removed. All that is needed from it is the part of the shaft connected to the gearbox. It needs to be cut off and the impeller removed. An M12 bolt is welded to the shaft trim from the head side.

You need to try to achieve maximum alignment. The protruding bolt head is ground off.

A bearing is pressed onto the modified shaft, and the previously removed gear is screwed on. Then it is installed back into the grinder gearbox.

A drill chuck is screwed onto the welded bolt.

A standard removable handle from an angle grinder is screwed into the gearbox itself. A meat grinder handle or a bicycle crank is clamped onto the spindle with a nut.

The result is a very good hand drill.Due to the gear ratio of the gearbox used, for one revolution of the handle the drill makes from 2.5 to 4 revolutions, so drilling is not as slow as it might seem.