I assume you're talking about a glidecam of some sort, as a steadicam would cost you far more than $30 to build. That being said, if it is a glidecam that you are looking for, and you want a cheaper one, I would just save up for an Opteka SV-HD. Nothing you can make for less than $20 is going to be smooth. I've had mine for a couple months now, and absolutely love it. It takes a while to set up/balance, but if you spend some time with it, it gets really easy.