Router Mortising Jig + More on Mortising Bits

[Greg Guarino]

I built myself a mortising jig today. It still needs a couple of toggle clamps and possibly one more stop for the work, but it's coming out pretty well.

The router moves smoothly laterally, and it's easy to set the mortise length. I added a movable work guide underneath for more repeatable results. And I made it to be held in my bench vise, which is very convenient.

But ...

The thickness of the jig limits the depth of the mortise. Sort of rethinking and rebuilding, the through mortises (in 1.5" stock) I'll need will require extra-long bits.

I'm looking into something like this:

It claims 3" of cut depth. Comments?

[Lew Hodgett]

"Greg Guar>I built myself a mortising jig today. It still needs a couple of

---------------------------------------------------------- Your mounting plate could stop a Sherman tank.

I've built and used this one couple of times.

Simple and straight forward. No need to reinvent the wheel.

Lew

[Puckdropper]

Greg Guarino wrote in news:mgf8jq$d4h$ [e-mail]:

*snip*

Looking at the end, I don't believe it's center cutting. That's not a hard problem to solve, though, just take a 1/2" drill bit and make a hole.

Puckdropper

[Greg Guarino]

Yes, what about that? That's the common situation with end mills, from what I hear; but some people recommend them for woodworking. Incidentally, on that site they have used the same photo for all of the products in that class, but I imagine the end, at least, is representative.

[dadiOH]

It does look pretty solid, doesn't it? :)

Ones I have made have been similar. Different in as much as I don't attach to router but to work; moveable strips on top to limit router travel. Similar because it is thin...1/4 hard board or ply.

[Greg Guarino]

I tried to make it for multiple uses. ;) It's a dangerous world out there. That is one feature of my nascent skills; what I lack in finesse I make up in sturdiness.

I like the fact that mine has defined stops, although I could imagine how you could clamp stops to the work with the jig you show. If I can't come up with a longer bit I might try that one.

At least half my output is in reinvented wheels. :)

[dadiOH]

If the cutting diameter = shank diameter, you can cut down a way, remove the jig and cut the rest by guiding the bit shank on the hole.

[Greg Guarino]

That sounds like a pain to do 16 times. I'd probably jsut opt for a longer bit, or a thinner jig. But I'm curious to know if it's even safe. Any opinions from the group?

[whit3rd]

If you can trust the (round) base of your router, you can omit the plate and guide bushing, guide with the external frame against the router base. A sub-base can be made round, centered, and in any desired diameter by chucking a dowel pin in the router, and pivoting the router on that pin - either a second router, or a router table, can trim the edge of the subbase.

The subbase, of course, can have a 2" hole to clear the router chuck. And if you make several of different diameters, changing them in will make a single jig produce multiple mortise sizes.

I hear the wail of gotta-use-multiple-tools, and sympathize. A recent bookshelf with half-dovetails needed five cuts per shelf end, with two different router bits (half-dovetail, you know) and the 24 shelves took all weekend, I've fantasized about multi-shaft circular saws with 1" blades to define the sliding half-dovetail sidewalls.