all quality bits are expensive
But the more edges and shapes the more complicated the "craftsmanship" so
the more expensive it becomes.
I would sell you mine but it would be cheaper for me if you would just go
out and buy one.
"Subw00er" < firstname.lastname@example.org> wrote in message
There seem to be two sizes of lock miter bits, CMT having the
Baby Lock Miter and the Lock Miter. The former is for 3/8 to
3/4 inch stock, the latter for 5/8 to 1 1/8" stock.
I just did a pair of baltic birch ply drawers for a sharpening
station cabinet I'm doing. Tried the drawer lock bit first but
mine was too big for 1/2 inch ply. I avoided the miter lock
because I thought it would be a pain to set up. Turns out it's
a lot easier than I'd thought.
Here's the url of stuff I put together - including two jigs on
the next page you should probably make to do the horizontal and
the vertical cuts.
(all one line so watch the line wrap)
There's a link to wood shop demos that has a slick set up process
that's easy to understand and actually use.
Assuming the boards to be joined are the same thickness, here is the method I use:
1) You need two scrap pieces of board the same thickness as your work pieces,
and a good thick straight edge with crisp edges.
2) Figure out the "center point of reference" on your lock miter bit. Not all
bits have the same design, so this is tricky to describe. Charlieb's webpage
shows an excellent diagram of a CMT bit, but whose design is representative of
one that I'd classify as a "pain in the butt" to adjust. This is because the
"center" of the bit is at a point halfway down a *sloped* surface. It's much
easier if this surface is parallel to the table, because that surface defines
the "center point" in bits of this design.
(hope that last part wasn't too confusing)
3) Adjust the height of the bit in the table so its center point is exactly
half the thickness of your stock. This is the critical setting, so don't
change it once you've found it! I use a marking gauge to locate and scribe the
halfway point in a piece of scrap, then adjust the bit by eye to line up with
4) Next comes the fence adjustment. First, adjust the fence forward so the
bit will NOT make a deep enough cut in the wood. Place the two scrap blocks on
either side of the bit (vertically, against the fence). Lay your straight edge
flat on the table against the scraps. Then adjust the fence backward (keeping
the blocks trapped between the fence and the straight edge) until the router
bit cutter just "kisses" the bottom edge of the straight edge (you'll need to
turn the bit by hand to find this sweet spot). Lock the fence; you're done!
At this point it helps if you have one of those fancy Incra or Jointech fences
that can remember the current fence location (if not, you can clamp some stop
blocks to the table on the back side of your fence to create a rudimentary
memory system). What you want to do is make several passes to get a clean cut;
you do this by starting with the fence moved forward, then working back towards
the "home" location.
My explanation looks complicated, but it's really a simple process once you
understand it. Using this method I can install and adjust the bit in just a
few minutes, without using pre-cut "setup blocks", and without going through a
bunch of trial-and-error test cuts. I can usually get the settings right on
the first try.
To reply, change the chemical designation to its common name.
Get it out and try it - you'll like it. And once you get the set up
for the stock thickness make your own set up block out of MDF, one for
the horizontal cut and one for the vertical cut. The bits make for
easy drawer joints and boxes - mitered corners without splines,
or biscuits. I've also seen them used to build table legs with
figure on all four faces - quarter sawn oak especially since the
pattern is only available on one face of a board.
You cut one piece face up and flat and the matching piece face away
from the router fence.
Both the bit depth and the fence overhang are critical to both cuts.
They are not fun to set up. Trial and error. It is absolutely critical
that your pieces be flat the edges true and that you keep track of the
inside and outside faces. If that sounds like the voice of oops, you'd
When you dry fit the cut check the inside and outside edges to make
sure both are 45 degree angle cuts. Any evidence of a 90 degree angle
means the pieces won't mate.
It simplifies things a bunch if all the pieces are the same thickness.
If you did it perfectly, the pieces almost snap together. Any errors
will be immediately apparent due to your crimson red cheeks :)
On Wed, 14 Jan 2004 21:55:04 -0500, Eddie Munster
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