Чурбачок is a diminuitive form of чурбан. Чурбан is a block, a piece of wood used to chop wood. На чурбачок его ставь. - Put it on the block.

The diminutive for чурбан, fool or insensitive person. What's the context?

Chopping block it is. In Russian it is normally a whole section of the trunk of a tree and does not apply to cutting boards or anything else. As such it is not commonly used. Чурбан is also a derogatory name for immigrants from certain countries in the Caucasus region.

Thanks :)

http://s00.yaplakal.com/pics/pics_original/7/8/9/1532987.jpg вот он =)