jesus guys sit down and draw out the plans yourself, its not like it needs to be well engineered. I honestly sat down at burger king, drew out plans on a napkin, went to Lowes and built a box
yeah, but the funny thing about badly engineered boxes is they tend to break if you hit them more than a few times. any idiot can take a six scraps of wood and screw them together, but that doesn't mean it will slide well on skis.
I based my box off of these plans, but made a couple changes to make it a bit easier to put together. Also the build-a-jib 101 cult has a lot of really helpful information in it.