A sacrificial fence is used when the table saw blade is running right up against the fence. You don't want it rubbing against the actual fence or it could damage your fence and dull your blade. A side benefit of this setup is that you can use it to saw off less than the thickness of the blade (dado or regular), by bringing the saw into the sacrificial fence. You'd do this by setting the fence location with the blade down, starting the saw, then raise the spinning blade into your fence.
Wouldn't a stop-block on the fence have been safer for cutting the dado? Sliding a piece along the fence while trying to keep it square to the miter gauge can be problematic. I understand that you have a premium miter gauge and you were only working on small pieces. But with a slightly bigger piece or a cheap-o miter gauge you could get yourself in kickback-town pretty quickly.
Hello and thanks for the tips on a locking Rabbet. I'm a beginner, but have working in a wood shop using hydro-saws for miter cuts. I purchase a little home table saw for hobby and would like use this "locking rabbet" system on a shadow box I'm building. Is this possible? Thanks for the posting...
Don't you think passing back over the dado toward yourself was a little risky and dangerous. The initial pass cuts completely, the return cut seems ignorant of the dangers.
Rob I Thanks for the reply. I had forgotten about this comment. I had to review to make sure I was not seeing things. The artifact occurs at 6:18 not 6:21. If you play the video at 0.25 speed you can see two + occurs at 6:17-6:18 lower half of the image.
How many people own a "keyway key"? Showing how-to videos with very specialized tools is not a very good instructional technique. Very fine furniture etc has been built in the past without these fancy tools.