Re: End bar router blowout
Router bits are circular (obviously). But since they rotate in only one direction, you have a choice of whether to feed in the left or right direction. In one feed direction, the rotation of the bit will tend to push the cut wood away from the main piece. In the other feed direction, the effect will be to pull towards the main piece.
So if you are having problems with splintering, try feeding the wood in the other direction to see if that helps.
I don't use a router in making my frames - I add the taper to the end bars, (before they are sliced off the original block) with a jointer. But I do understand that not everyone has access to a jointer. You may also find that making shallower, multiple cuts with the router reduces blowout.
--- Victor Hugo - "Common sense is in spite of, not the result of, education.”