Centering Base Plates
I know the basics about centering the plates on my Porter Cable router bases but never get them exactly centered. I was hoping to get some feedback on the process.
The PC bases are mounted to the base with 3 countersunk machine screws. After removing the screws and the plate, I counterbored the exsisting countersinks on the plate with a 3/8" Forstner bit and enlarged the through hole a little bit. I replaced the original countersunk screws with the appropriate size pan head screw. The counterbore is deep enough to allow the new screws to sit below flush. The modified and enlarged holes should permit me to align the base (with a bushing installed) to a centering pin mounted in the collet. I use the centering pin that came with the bushing kit (Rockler #59031). After alinging the base with the pin I tighten the screws on the plate.
After all of that, I run some tests and get off-center results. There have been times after chucking a bit in the collet I visually check and can see that the bit is not centered.