Here's some pics of my one I took when I was doing a re-handle.
The timber on either side of the jig is to be set against a fence on a band saw. It's proabably not worth telling you the measurements as I have made it specifically for my saw. All I will say for this method is that if you are using a band saw with a blade less an inch wide, then it is very difficult to stop the blade twisting while you are cutting and is not necessarily better than cutting by hand if you are, like me, not making lots of bats! It will be fine if you go really slowly though!
If I remember I'll take some photos of my handle jig to add to the thread.