Daiku

The lock mortise routers certainly plunge 5 inches and use bits from 3/4 to 5/4 diameter but I do not recommend them for timber mortising.

Thanx for the help. Will try the extension. I plan on using 2 routers for each mortise. The first with a collar to dig up to 3 inches, then grab the heavy duty router to continue deeper. Plan to remove chips with air pressure, pop out the center (when practical ) with the grain using the chisel (after the perimeter has been removed.) Will also try to hollow out the center with 1" bit on 1/2 drill.

Will you be making round tennons, like a Hundegger, or will you chisel the corners? I think you'd be surprised how fast you can get cleaning up a chain-mortised hole with a chisel. Good luck to you. CB.

I especially like routing along the outside of housed dovetail pocket with a template and with one crack of a mallet having the waste come out in one piece.

I'm using a large Bosch router to finish 2 inch deep mortises and pockets with no problem.. This is in green Hemlock with a 2.5" cut 1/2" dia cutter. But I do two 2.5" drilled holes and a circular-saw edge cut where possible, and often chisel out the big chunks. The finish-up is about 30 or 45 seconds.

The MAIN thing is that the jig holds very close tolerances on final dimensions and the fit is excellent every time without fussing..

Even on big straight-cutout half-laps in 8by8 timber I use the router and a jig just making a 1/2" deep cut. There is almost no tear-out cutting with an electric chainsaw and a perfect guide for the cut every time. I do have a jig for holding the chainsaw nose on each half-lap cut, though, and that makes an accurate cut right down the routed line pretty easy. I smooth it a bit with the chisel to make myself feel good. But I probably digressed!

There's an interesting subject of jigs and tooling that I'd like to get into some other thread. Then there's the pickup-truck crane...

I am always leery of the "New and Improved". I often see it as coming from people who are relatively unskilled with their perspective Tools, be they Handtools or Power.

Tools require an Investment of time, as well as Capital -- Handtools generally requiring far more Time, far less capital, with the tool becoming more, and more accurate, as one's eye becomes more and more trained, the tool also becoming faster, and more efficient as one's muscles grow, as mostions become second nature, as, Finally, the tool and the Body meld, the right tool for the Job, and the right hand behind the tool.

There is less time which needs to be invested in Power Tools, but it is Still there, so much so that, OFTEN, instead of needing a new tool to acomplish a time worn task, what is needed is a little more practice, a bit more investment in skill, and an eye cast to seeing How the more experienced do things. What tools they use, how they use them, and in what order.

Notes from the field:

I have just recently been working on a frame for an addition to my house.
I have been intrigued by this topic and having posted opinions previously I thought perhaps I could test my theories and observations and/or learn something. (It could happen!)
Report as follows

Project: Thru motises-7 ½” & 9 ½” deep, cross sec-1 ½”x3 ½”

Material: #1 Doug Fir

Tools:
· 1 ¼” drill bit
· 3/8” drill bit,
· 1-1/2HP Router w/½” shank 2 flute bit 2 ½” cut length
· Reciprocating saw w/12” blade (don’t be frightened)
· Chisels and slick

Procedure:
· Layout mortises and score across grain
· Build jigs for router (dimensioned to index router base) and 1 ¼” drill bit
· Drill two holes 1/8”from both sides using site built jig
· Remove waste between holes w/saw (carefully) Starting at top and slowly moving saw to vertical
· Attach jig using screws where it won’t show, clamps where it will
· Set router to 1 ¾” –2” (depth not critical), remove material by “circling” around hole removing approx 1/16” per pass
· Set router to greatest cutting depth (3 ¼”) and repeat previous
· Repeat routing on other side of beam
· Drill 3/8” hole at corners of mortise thru material left at center.
· Remove remaining material and true mortise with chisels and slick

Thoughts and suggestions:
· I would suggest a larger router (in my case this was disallowed by a bout of budgetus interuptus),
· Keeping more than one bit on hand if doing production work.
· My plywood jigs seemed to be showing signs of wear, if long use is expected and the joint is standardized enough, perhaps metal jigs?
· A fence on the jig indexing the reference face (if doing square rule) might aid both speed and precision
· I a top bearing bit or a base mounted guide might allow for aligning the jig on a parallel plane with the reference face if it is on the opposite side of the member. This would keep the tool in alignment with the reference face. (Not incidentally this technique would work well for housings)
· Hearing protection for everyone within half a block. This is the loudest possible bit in a loud tool.

Overall I think the router could be a great tool for quickly cutting precise, standardized mortises after most stock has been removed by other tools. Used in conjunction with a chain mortiser I think that this could be a technique that could be very fast and quite precise.