What is this device good for?

[radrush]

The given description reads:

 

[koditten]

Knife makers would find this useful. Could use it to sharpen mower blades if the blades only need an edge cleaned up.

 

[bad_idea]

useful to help with lower back pains caused by a fat wallet.

 

[Regnar]

Search on YouTube for KMG Grinder and you will find your answer. But basically it makes metal disappear quickly without a lot of heat transfere.

Also don't buy the plans. If you use your google foo you should be able to find the plans online for free. I know I picked mine up a few years ago on Pirate4x4.com