Hope not too off topic, does anyone have books on building simple electric-powered machines? I often have ideas for little machines for my garden or cooking but have no idea how to go about selecting motors, controller boards, designing strong enough parts for my 3D printer, etc. I'm not expecting an all inclusive book for such a deep topic. A series or several books would be much appreciated!

Used to love building robots with Legos as a teenager, but alas the real world isn't so simple. ;)