Welcome! I see this is your first post so let me say it is good to hear from you.Sherwood said:I have a Sears Dovetail fixture which requires a 0.50 inch guide bushing and a 9/16 inch dovetail bit for cutting through dovetails. My problem: how do I limit the depth of cut while making sure the carbide cutting edge of the dovetail bit does not slice into the inner diameter of the guide bushing?
I understand, of course, that the router collet can be raised and lowered a small amount and that the bit shank will vary in size. Is the only way to "adjust" for this depth of cut problem 1. buy a bit with a carbide edge that is longer or shorter or 2. attempt to use a dovetail bit with a different vertical angle?
Can any size/diameter guide bushing be used in cutting dovetails as long as the outer diameter of the guide bushing easily moves in and out of the dovetail template guide fingers and cleans the wood completely?
Since you mentioned the 1/2" guide bushing and 9/16" dovetail bit my guess is that you are trying to do a thru joint without the right bit. I'm also guessing that you have the manual. Anyway the manual calls for a Sears bit 25414 that you need to use.... If you have that then you should be all set.......... if not then you will have to get one like it from somewhere. When you see the bit it will be clear why they ask for that bit. Now check to make sure that this # is the bit your jig calls for as mine might be a newer or more likly older one then yours.
As mentioned in the other post make sure the bit can not retract into the bushing if you have a plunge router adjust it so this can not happen.
The front of the jig has a bunch of standard depth settings which is a good starting spot for getting the bit to the right height. It is also very importain to get the bit centered in the guide bushing....... The guide bushing screws in tight, you should not attempt to adjust the height this way.
Make sure you make a few test cuts before working on your project and read the manual over a couple of times.... they didn't do a very good job on the manual. If they ask for backer boards and spacers make sure you use them... If they call for them to be 1/8" to 1/4" thicker do it.... I've seen some of these jigs used and torn up because the insturctions were not followed. After you see how things work then you might want to play around but get a little experence before you take off on your own.