dusty wrote:Those are nice illustrations. There is one missing though. The one that I think would be very beneficial is the one of a work piece trapped between the fence and the blade.
I supposedly learned NOT to do that but I have done it twice.
In case anyone does not know, if you trap a work piece between the fence and the cutter the work piece will be shot across your shop like a bullet. Very, very ill advised. DO NOT DO THIS.
Dusty, I was a bit stumped when you first brought it up .. it's a pretty challenging thing to illustrate. But I thought about it some more this week, and here's my best shot.
First up, here we have a workpiece being fed between the router bit and the fence, in the same direction that the bit is spinning.
The woodworker probably wants to make a cut like this, with the fence-to-cutter distance set to provide a nice uniform workpiece thickness.
But alas, the bit cutters don't cut -- they instead become sharp cleats that bite into the workpiece, accelerate it up to the cutter speed, and fire it across the shop like a baseball-pitching machine. Lets just hope that the woodworkers fingers don't follow it into the bit!
Now let's say that's a 3/4" diameter bit in the illustration. So the cutting circumference is Pi * 0.75 = 2.36". My PC 690LR router spins at 27,500 RPM, or 458 rev/sec. Thus the cutter speed would be 2.36 in/rev * 458 rev/s = 1080 in/sec. That's a cutting-edge speed of 90 ft/sec, or 61 mph, folks. And that router has ample kinetic energy to fire a good-sized workpiece at very close to that speed.
So what happens if you feed the workpiece from the opposite direction (opposing the cutter rotation)? I have some theories, but I'd like to hear what other people think.