As a treat to myself, I had my wife buy me a 4212 dovetail jig for Christmas. It has a lot of whistles and bells and I had wanted one for a while.
The week after Christmas, I finally got a chance to go out and give it a spin.
Knowing that dovetail jigs are "very" twitchy to get setup, I cut a armfull of plywood drawer sides and got the jig set up on the bench.
My worst fears came to past after a couple of hours of screwing up a "lot" of 1/2" plywood.
I was trying to make half blind dovetails and I wanted this jig for a future project that requires drawers.
No matter what setting I made, this jig was NOT going to make a "hand fit half blind dovetail". I called a day and resumed the next afternoon.
(1) I set up for through dovetails.. That worked. (2) I set up for sliding dovetails.. That worked. (3) I set up for box joints .. That worked.
It would NOT make a useable halfblind.
I called Porter Cable and tech guy said.. "That's odd".
He did mention one little thing "it sounds like the bit is bad" but he discounted that option pretty quickly and suggested I try a couple more things.
I was disgusted... but I called my tool store and asked if they had replacement Porter Cable bits for the jig ???
"No"..but we do carry the Freud bit for that jig.
I took it.... Freud 22-115
Saturday I put the new bit in the router and setup the jig "exactly" the way the book describes for the test.
Made a test cut....
Almost PERFECT on the first pass. It was even a little loose but it was a hand fitted half blind dovetail.
I was amazed to say the least.
I'll be making a phone call this week to the folks at Porter Cable on their router bit purchases.
Just for the record, the 4212 is really a nice jig that is capable of doing very nice work, once you get the correct router bit.