I have a Craftsman 10" band saw, and just put a new Timber Wolf blade on it. I tried using a circle jig on mine, and had the same problem and couldn't figure it out. I was cutting a 3" circle with a 3/8 blade. It cut great if I freehanded it, but when I used the jig it would bog it down and all most stop. It's a brand new blade, so it must have been something with the jig. I followed a video online to make it, and was very simple-just a board with a nail in it. I wasn't able to use it. I thought maybe it was the saw itself, and wasn't powerful enough, but after reading your post, I'm wondering too.