Thank you for the kind words.  It's a bit of both.  I do enjoy working with machinery but it's really a matter of necessity that I do it so much.  I save myself more money than I could make given the amount of time I invest in these projects.  For example, I saved somewhere between three and five thousand dollars by replacing the engine in my car myself.  I currently have no other way I could make that kind of money in a weekend, and I already have the expertise required to do the job, therefore it's well worth my time.