Ok….how can a young fellow like you have grandkids that age. You must be renting them.
I’ve had many Scouts through my shop and usual it’s a structured project do to time constraints. I’ve always told the boys, as well as my own, if you have an idea of something to try you’re welcome to come back with Mom or Dad and we’ll “have at it” .
Involve your kids and grandkids. They'll love you for it!