Did you use fine thread or coarse thread screws?
For hardwood, they recommend fine-thread to help prevent splitting.
Jason
Printable View
I've never built doors with my Kreg, but I have seen wood split when I put in a screw close to the end of a piece. I'm not sure how you could overcome that other than to C-clamp the piece with lots of pressure while the screw is being driven in and even that may not work. It takes a bit more time, but I prefer to use lap joints for all my door frames. The lap joint is very strong and pretty easy to make with a TS and tenoning jig.
Since maple is dense, even 'soft' maple is as hard as cherry, you might try drilling a pilot hole into the receiver. I have a 6" 1/8 bit that I used when I experienced the same problem. I knew the wood was very dry and the first screw confirmed my suspicions! I setup for driving the screw, then drill thru the pocket, then drive the screw.
Fine, just like it recommended. I think they were just too close to the edges. Here is another quandary.....when i set the collar on the drill bit, should the tip protrude the end of the work piece or not. Because mine didn't. I know they are self drilling, but should the little part of the bit go thru the end?
Mark,
I set the drill stop so that tip just penetrates the wood. I also suggest you not use power drill near the end of the screwing. It is easy to go too far fast. When the screw penetrates, I back out drill and hand tighten the rest of the way.
There was a Fine Woodworking Joint test a while back that was very favorable to Pocket hole Joinery. If I recall correctly it really gets down to penetration from one piece of wood into another.
Scott