Lock Miter Tips and Tricks
Advice on getting good results with a lock miter bit. August 15, 2006
Question
Does anyone have any little tricks on using the lock miter bit? When I run the vertical piece along the fence, I use a scrap piece to guide it, but it still rocks back and forth a little as it passes through the router.
Forum Responses
(Cabinetmaking Forum)
From contributor A:
Make a jig with a lever clamp and use a feather board on your fence.
From contributor R:
I scraped this design off Lockmiter years ago for the one that looks more like a tongue and groove. I find it easy to set up, but it does require one extra step. You have to set up a dado on the table saw to cut out the tongue on one half of the joint and make a groove instead. Maybe a little more time consuming, but easier to set up and all materials are run flat on the shaper table. You have no restriction on how wide the material can be when using a feeder.
From contributor J:
For the rocking, you need a tall fence. It's a whole other piece to make and install, but it's crucial. Also, if you can, mill the stock that will be run vertical with at least a foot of extra length. This leaves some solid stock for support on the table so your good part won't crumble and snipe where it shows. On large runs, I have used the power feed turned horizontal and angled down a tick with the entire pressure area on the infeed side of the cutter down at the table. It makes a sweet fit.
From contributor J:
P.S. I didn't make clear that the power feed is pressing against the work material, and thus the fence with "the pressure area on the infeed side of the cutter down at the table." This begs another point - make sure your fence is extremely well tightened in place, as this pressure is more than usual feather boards. I usually add an extra clamp to each side of the fence to be safe.
