Lewis wrote:
Hi,

Good morning Lewis,

I'm getting ready -- finally -- to mount my router in the end of my table
saw extension. I'm planning to use an auxillary router fence mounted to the
TS fence, and stand facing down the length of the extension. Two questions:
First, how far back from the front end of the table (in my case, the end of
the TS extension table) should the router be?

That's kind of an answer dependent upon what you are doing
as Edwin has already mentioned. In my case I have a 24"
deep table and the center of the router bit is 16" back (1/3
2/3) from the front edge. I like as much real estate in
front of the fence as possible for large(r) pieces and this
isn't so far back that I feel I'm hanging over the table
when I'm using it. Also, because of design I needed the 8"
to be out the back so I could mount the router and have
space for a fence (mine is a stand alone (stationary) router
table).

The extension table is close to 60", so space behind the bit is no problem.
What is a good way to decide how much table should be in front of the bit?

Personal comfort and how much out the back you might need to
mount a fence though in your case the latter isn't a factor.

18" seems to be a comfortable reach, but that seems to be a little further
back than most tables I've seen.

A lot of tables I've seen have the router very close to the
front because the user has an Incra style fence which pretty
much dictates the bulk of the table to the back side.

Pat Warner's, for example, appears to be 13-14 inches
(http://patwarner.com/router_table.html). Is that a function of the overall
size of the table? If so, that's not a factor in my setup. Or is there some
reason to keep the bit closer to the front?

Believe it or not, and this could just be me, I have found
that despite the small tables on machines like band saws and
drill presses (and router tables) we seem to get by.
Despite this finding I still prefer more table for my router
but I have gotten by with less.

Second, I have a piece of 3/8" aluminum approximately 9X12" for the mounting
base. I'm thinking of cutting it down to 9X9, so it's a little lighter
weight,

Weight, in this case, isn't a factor unless you are wanting
to use the base outside the table (not a bad idea some
times/you will when you need a wider base for free hand
routing) and even then the 3" X 9" of "extra" aluminum isn't
going to kill you.

and so I can put a smaller hole in the extension table. What are the
advantages and disadvantages to a big plate vs. a small plate? A 9X9 plate
should be big enough to mount any router, right?

Maybe, maybe not. Wider inserts will allow you to clear the
handles on the router base. For instance, the 3 horse
Porter-Cable router measures 11 3/16" (ish) from handle to
handle. By mounting it slightly off kilter the handles will
clear the insert hole with an 11" insert.

I'm planning on using my DW618, leaving the fixed base more-or-less
permanently attached, and I'll use the D-handle base Santa is bringing
for hand-held routering. Even if I get a bigger router in the future, I would
think 9X9 would be plenty big -- unless there's a reason I'm missing for
a bigger base?

See above. I'd leave it 9" X 11" but that's just me.

Thanks, and Happy (US) Thanksgiving!

You are welcome and ditto to you and urine.

UA100