On Tue, 03 Jan 2006 17:32:21 GMT, Rick wrote:

I am looking for a LONG straight router cutter, to cut a grove in a
piece of oak.

I would much rather saw this than rout it. I would even rather make up
a one-off plywood sled so that I could pass it throgh my nice safe
tablesaw rather than routing it. I might even saw it by hand (with a
bellied floorboard saw) rather than routing it.

Ideally I want to get to a 75mm depth, about 12mm in diamater,

These are easy enough to find. There's not many of them, but you can
usually find 3" - try looking under kitchen worktop trimmers. I think
mine are Trends of about 1/2" and there's a Yellow Axminster one too
with a bearing guide (at the shank end) that sees an awful lot of use
for multi-part template routing.

I am cutting a rebate for a door, into a lintel. We have cut the
lintel out of an oak branch, so the bottom still has the bark on it.

You know this is going to twist like crazy don't you, especially if it's
branch wood. I'd certainly cut it almost to shape, leave it a week to
settle down then re-cut it to the line. Even then I wouldn't use this
branch for a few years after cutting it. I use oak "knees" to make
curved chair backs without having to steam them, but I like those to be
at least 5 years old first.

Also watch out for bugs. Most of the domestic oak pests like to live
_just_ under the bark layer, around the thin sapwood. I'd poison it
before use, or else expect that in a few years time the bark splits off
and you're left with bare tunnels.


While I am asking, I also want some long straight edges, to clamp to
some wonkey oak planks, and drive the router along to strighten the
edges.

Long straight edge guides are an essential add-on for any serious
routing. It's worth finding good ones (but don't part with proper money
for them, that's just not decent). Solid aluminium is too flexible
relative to its weight, you're better with box sections. Mine are scrap
from windowframe makers.