Drawboring bench end caps question

[Michael Hammers]

Hello, I am building a Federal style workbench. More recently a Mike Dunbar style. I am loosely following the plans from FWW. It is an all wood project so I am rejecting bed bolts and also bolting the endcaps. I want to use a large single dovetail for the far end of the bench connecting to the back piece and then drawbore instead of bolting into the bench ends. The other end has a shoulder vise so It will only DT to the back piece. Has anyone tried this? Any and all info would be great.

Particulars:
Walnut top 2 3/4" x 4 7/8 thick
3/4" x 2 3/4" african mahogany sandwiched betwixt the walnut :D Each section will be 5 5/8" wide and it comprises 5 sections. Making it a bit over 28" wide. Anyone think I should go one more section wider. No tool tray I think.


Thanks, Michael

[Pam Niedermayer]

If you mean a long sliding dovetail, no drawboring will be necessary.

Pam

[Mark Singer]

Drawboring will help to pull the mortise and tenon together....don't over do it or you can split the tenon and break the grain...1/16 th off set or less. That will draw th joint together. Or get a long clamp and pull it together. If you use a sliding dovetail it will be hard to assemble with 2 aprons to match to the end caps.

[Ken Bryant]

I can't picture where the dovetail is, or what gets drawbored. Diagram...? Also can't picture how all this accomodates movement. Is the top vertical grained?

[Bob Smalser]

It is an all wood project so I am rejecting bed bolts and also bolting the endcaps.

I want to use a large single dovetail for the far end of the bench connecting to the back piece and then drawbore instead of bolting into the bench ends.

The other end has a shoulder vise so It will only DT to the back piece.

Particulars:
Walnut top 2 3/4" x 4 7/8 thick 3/4" x 2 3/4" African Mahogany sandwiched betwixt the walnut

Each section will be 5 5/8" wide and it comprises 5 sections. Making it a bit over 28" wide.


It would help for you to look up the terminology before you take advice based on a misunderstanding. Any cabinetmaking book like Frier's Cabinetmaking and Millwork , a standard reference, will provide the terms.

In general, your bench is way too wide to work both sides, and dovetails don't need pins. Unlike in a M/T, shoulder fit in a dovetail joint has nothing to do with clamping pressure, and in a sliding dovetail designed to move seasonally, a pin would hurt rather than help. Bigger isn't better in a bench..the wider it is, the harder it is to flatten and keep flat when it moves seasonally. Build a separate assembly table to have a large, flat surface.

http://pic20.picturetrail.com/VOL12/1104763/6583947/84781053.jpg

If I understood you, an "end cap" or "breadboard end" is generally called a cleat, and a sliding dovetail instead of a tongue and groove joint has no advantages. Fitted correctly, the T&G won't fall apart.

[Michael Hammers]

Here is a link to someone who made their top in a similar fashion. Dunbar's design does not incorporate any endcaps on the left side of the bench.
This design uses a T&G and it looks like bolts also?

http://pages.friendlycity.net/~krucker/Bench/EndCaps.htm

I have considered the sliding dovetail but think that the "bread-board" design is much easier. I suppose I was concerned about having just a glued T&G on the end.
As far as wood movement. The walnut is quarter-sawn and is alternated with grain orientation plus the 3/4" mahogany should help limit movement. i am more concerned with drawboring and or bolting the ends as to much movement will bust it apart.

[Alex Yeilding]

I also built my bench with a "no metal" mantra. But I wasn't completely pure--I predrilled, except for the outside layer, for a threaded rod to hold the shoulder, then marked on the underside of my bench the location for drilling the last little bit if I need to add that in the future. ("Drill 2 3/8" above this pint").

My endcaps are held on similarly to the one in Rucker's bench you pointed out. And that is a reason for a tool well--You can firmly attach both the front and back end of the endcap, and let one side of the tool well float in a dado to accomodate movement of the top. (If I remember correctly, Rucker has it moving under the top.) Then the front and back boards of the bench tie the endcaps firmly together, and against the ends of the bench.

[Michael Hammers]

Alex,
you are spot on. The whole tool tray aspect sort of gives you what you need to tie it all together. I am not a tool tray fan and want to keep the symmetry of the top together. I am not keen on his use of the dovetails though. So I have been trying to come up with an alternative. I also have to watch the underside as I am using two large (LARGE) wooden screws for the front vise and I do not want anything coming close to interfering with them.
The "all-wood-mantra" is a harsh taskmaster. I just also wonder if it would be just as advisable to leave the ends "raw".
I have done the base with large thru "tusk" teonon's. I think it will be sturdy enuff!