Experience With Making Their Own Sleds/Prowlers?

A while ago someone posted a site that had a bunch of DIY strength equipment. Does anybody know what that site is? I’ve been a little short on cash lately so I think making my own would be the best idea.

This guy does a lot do it yourself stuff, you may have to hunt around on his site a bit to find it:

Just realized you were asking about sleds in specific so this might help as well:

^ Thanks! The tire on is a great idea.