Who says little ones can't help out in the shop? My husband is a woodworking hobbyist. Our house is scattered with his various projects, all beautifully made and handcrafted. This means that he spends a lot of time down in his shop - a place you would normally want to ban kiddos for fear of someone stepping on a nail or smacking their head against a sharp corner.
But our little 4 year-old loves spending time with Daddy in his shop, and he's found ways to get her involved, safely. If any of his saws are on, she wears ear protectors and goggles. He's also taught her how to safely wield a hammer, and she's practiced nailing into wood. Mainly, she likes wheeling around the shop on an old tricycle :)
Do you involve your children in "grown-up" hobbies?