Re: More bench design questions:
Adam Cherubini
>I'm planning on the top being 12' by 30", on a set of legs and stretchers that will be 8' by 30" - first question: how far can I hang my top off, on the right end of the bench? I'd like to hang it over one foot on the left, and three feet on the right; is this too much?
I think so. You want those legs out at the ends. Yeah the bench will sag a little. You can plane some of that out. But sag really isn't the problem, flex, may be though. I wouldn't sweat it. I could try to put some numbers to it if you are really curious.
I'd put the crochet as far to the left as is structurally sensible. The left leg should be positioned so that a 3" thick board can be placed into the crochet and still hang over a peg in the left hand leg. Nothing is arbritrary, so I don't recommend guessing.
On the right hand side you must decide if you are comfortable placing your bench hook in your twin screw or not. If so, the twin screw can come close to the right end. The right leg should be in the middle of that vise. If not, move the right leg and TS vise one foot left.
Also, I'm planning for the legs and front stretcher to be flush with the bench top - but what about a sliding board jack, I know I need one - what's a good way to make such a thing, in this situation?
I didn't read garretts webpage (but I will). I think its smartest to make a groove under the top and nail a batten on to the front stretcher. The groove/ batten size should be such that the jack can be removed (deep groove). A groove at the bottom fills up with stuff and then the jack won't move.
And Adam, could you please explain/describe something you've mentioned before - a sticking board along the back of the bench? I have no clue what this is, or is for; and for what it's worth, my bench is going in the center of my shop, so it's not against a wall.
My friend and fellow New Jersean Mike Recchione, had a good definition. I prefer not to have a separate appliance but rather just attach a fence directly to the bench (either behind holdfasts or whatever. This fence, if thin enough, is useful for exactly the operation Mike described and is one of the reasons tail vises are not great. We often plane 45 degrees and a tail vise is then only holding the board through the friction at the dogs. The way to avoid complexity is to provide direct load paths. If you want to stop your board from sliding sideways, put a hard stop behind your effort.
Mike mentioned placing the twin screw on the left. First, the crochet is really sweet. It really works great. Plus, with a bench this long, you can have two things going at one which is nice.
Second, you really want the twin screws jaw flush or very nearly flush with the bench top. Ditto for the screw heads. That will let you work narrow stock. But this becomes problematic when you are using jointing planes with fences or molding planes. These tools sometimes overhang the bench top and would hit the vise jaw. (since teh planing stop is far left. You could move the stop right, but then you'd loose effective bench length. For what? The crochet can be 1" or more under flush, so planes with fences can run right over. Having the crochet undr flush means you can't edge joint narrow stock, but stock that narrow is too narrow for that set up. That needs to be donee on top of the bench.
I guess I think there are reasons for all this stuff. I'm not convinced I know them all or this way is best. But I say, stay in the box until you figure it all out and can outsmart it. Otherwise, you are working blind, guessing, assuming stuff is arbitrary when its not.
Anyway, that's my two cents. You can sorta see why I think a really good workbench book would be really interesting. There's a lot to this subject.
Adam