pwf  assembled this tool from spare parts of two other ones 10 years ago.

It survived many years of proper and improper use, but last week it was disassembled for good. Here are the rotor gears, completely grinded away at the end.

The round metal part on the right has been damaged as well.

This sort of damage mostly happens when a demolition hammer is thrusted into a wall forcefully, instead of holding it in place and letting it do its work. We need to buy a new one.