what is the best way to make this cut

[Derek Cohen]

I would not have a through mortice for a bench (as in the Chris Schwarz's version of a Roubo bench). This is subject to expansion and contraction, and what you see is the tenon either projecting through the top and needed to be trimmed, or the tenon contracting and leaving a hole that fills with sawdust.

My Roubo (built 6 years ago over 8 weekends) uses blind mortices. These are dry but pinned. The bench top is 3 1/2" thick and 22" wide x 78" long European Oak. It is bloody heavy and not going anywhere. The reason for pinning is simply to add a little insurance, but it is not needed. No glue because I want to be able to remove the top is we ever move. No drawbore since this would be difficult to undo. Pins (dowels) are safer.

A solid base is more important that through tenons. The tenons on my bench were going to be 2" in length, but in the end I reduced them to 1". This has been absolutely fine. The bench is rock solid, and I do a lot of hand planing on it.

The Jarrah base is also heavy and has 5" x 3 1/2" legs ...



Early photo of the bench top with blind mortices. Nice and clean! No tenon protrusions!



My recommendation is to rethink your mortice and tenon joinery. And, again, do not use the router for the tenon shoulders. Use the table saw to establish the shoulders.

Regards from Perth

Derek

[Wayne Lomman]

Derek, I'm curious as to why you don't recommend cutting the tenon shoulder with the router. Cheers

[andy bessette]

WL--table saw and bandsaw are much quicker.

[Wayne Lomman]

WL--table saw and bandsaw are much quicker.

Yes, as I said above, the router jig method is not the quickest. It does work on heavy timber with little effort which is the point. Cheers

[Derek Cohen]

Derek, I'm curious as to why you don't recommend cutting the tenon shoulder with the router. Cheers

Wayne, it is not simply that the router is slow and inefficient, but it is also vulnerable to tipping and gouging surfaces. The table saw will crosscut to depth and do so straight and true (no waste in the corner to remove). You can register the length of the tenon very easily, which will enable precisely coplanar shoulders - that is much more important than the smoothness of the cheeks. The tablesaw is simply the most efficient method for large legs.

The bandsaw (it appears you have one) is then set up to rip the cheeks. If you go blind mortice and tenon as I suggested earlier, then this is a simple matter as the tenon only needs to be 1" - 1 1/2" long.

The mortices can be cleared with a router. That is the only job here for it. Don't use it to level the cheeks - that would be like a canon in place of a fly swatter. Rather use hand tools to finesse the fit - rasps, files, rabbet planes.

Regards from Perth

Derek

[Robert Engel]

This!!!!!

rabbet block plane.jpg My excuse for buying one was this exact procedure.

Also, I would think it better to capture the tenon by putting shoulders on all 4 sides.

[Bob Cooper]

ok...thanks to all...very instructive to me to think thru the different ways to doing something that seems pretty simple.

One point of clarification is that all the mortises in Chris' plan are blind...none are thru. His tenons do run the entire width of the leg but the side of the leg in his design is no co-planer w/the top. When i eliminated the overhand i left the tenon just like he had which in turn made it visible. I was doing this more for looks than anything but based on this conversation i'm going to make but a smaller 1/2" shoulder on that exposed side. Not shown here but i should probably move that leg in so that it's not flush w/the side as well

Chris drawbores his legs and that's my plan. i am planning on gluing these in as this bench is pretty much being made for a specific location and is against a wall so hopefully i'll never need to dis-assemble it and move it.

Derek...that's a beautiful bench...totally a mystery to my how you cut those dovetails where your end vise it....but one day i'll get there.

My current plans are to use a twin screw vise as a face vice and an inexpensive wood vice for an end vice. Originally the plans were for the benchcraft scissor leg vice but the more i thought about the more useful i thought a twin screw vise would be.

[Bob Cooper]

figured i'd follow up. Well i decided to cut this on the table saw and bandsaw and i think it turned out great. Both my tablesaw and bandsaw are new...finally upgraded some mediocre equipment. So i had to build a new cross cut sled and that slowed me down a little but hey now i've got a nicely tuned sled. I also decided to make the tenon so that you do not see it from the side and i also put a shoulder on one side...it still left a very large tenon and allows me to get the side of the leg as close to the plane of the benchtop as i like w/o you seeing the tenon.

Anyway...here's a picture.

[andy bessette]

BC--attaboy.

[Derek Cohen]

Good work, Bob!

Regards from Perth

Derek

[Wayne Lomman]

Derek, the jig doesn't work like you suggest at all. It is neat, dead accurate, never causes gouging and needs no hand work to finish it. Nothing wrong with doing the job on a table saw and bandsaw though. Cheers

[Derek Cohen]

Hi Wayne

Can you say more, perhaps demonstrate the use of your jig?

Regards from Perth

Derek

[Wayne Lomman]

Derek, I can only refer you back to the details in my earlier post. I don't do video etc. If no-one wants to use the concept, that is ok. What concerned me was that perfectly good knowledge that is not the property of any one person could get so easily discredited. I did not invent this style of jig. I don't own any right to it. It would be wrong and selfish to fail to pass on this collected knowledge that is temporarily mine to use. Cheers