Request advice on workbench design details

[Eric Sink]

Greetings all,

It is time for me to build myself a proper bench. I am at the design stage. I am also not an expert on workbenches and would like to request some input from folks with more experience.

I do have the books by Landis and Schleining, as well as one by Sam Allen. They've been very helpful. Apologies in advance if I'm asking something that is covered in these books. I've read them, but I find that these books don't really work so well as a reference. They're great books when you just sit down and read them, but if I'm looking for some arcane detail, it's hard to find.

Here's an overall picture of what I have in mind:




It's a "tray in the middle" design. Of the many outstanding benches I have seen here on the Creek, I suppose my design is most similar to Chris Del's.

I'm right handed, so I've got the front vise on the left and a tail vise on the right end. For now I plan to simply build a shelf down below, not a cabinet.

The tool tray in the middle is a removable piece of 3/4 inch plywood.

The top slabs are 4 inches thick. I want this bench to be really heavy. Estimated weight right now for the whole bench is about 412 pounds.

The slabs are 14 inches wide, so I can run them through my 15 inch planer, and because I don't think they need to be any wider than that anyway. I plan to build the top slabs myself, laminating from pieces of 8/4 or 12/4 oak turned on their side.

The top slabs are 80 inches long. I'm not completely settled on this yet. I might go down to 72, just because I'm not sure I need lots of length and I AM sure that I hate working with long heavy boards.

Total height of the bench is 36 inches. I might change this to 35 inches.

The tray is 8 inches wide, so the total width of the bench is 36 inches. I'm aware that this is wider than average, but I'm okay with that. This bench will sit in the middle of my shop, not up against the wall, so I'll have access to all sides.

In my day job I am a computer programmer. The software I used to draw these pictures is a hobby project of mine. The light colored wood for the top is maple. I plan to build the supporting structure (the brown wood) from red oak, since I've got quite a bit of it sitting around wanting to be used. The software draws endgrain in yellow.

The software can't draw a vise, but I've included the jaws. So you can see the front vise on the left side of the bench and the tail vise on the right end. The tail vise is going to be a Veritas twin screw. I'm not yet sure what the front vise will be.

I've got 4 rows of dog holes, which will be round. They're spaced 6 inches apart.

The right end cap (also the rear jaw of the vise) is attached to the top slabs by cutting a tenon in the slabs and a dado in the endcap. I won't glue the whole length, so the top will have room to move.

The vise jaws are 8 1/4 inches, based simply on the thickness of the top and recommendations from the instruction manual for the Veritas twin screw vise.

Here's a picture from underneath:




The trestle has feet and bearers with two sets of long stretchers and one set of short stretchers.

I've got about 16 inches of overhang on the right side to give room for the vise hardware underneath.

Question 1: Is this too much? Is it a bad idea to cantilever that far?

Question 2: Are dog holes supposed to be drilled all the way through like this? I think so, but the books don't usually show pictures of the underside of a bench.

Question 3: What about the dog holes in the vise jaws? Should they be drilled all the way through as well?

Here's a picture of the left end:




(My software draws plywood edges in red.)

The tool tray is supported by dadoes cut in the side of the top slabs. The dado is an inch deep, cut one half inch up from the bottom of the slab.

Question 4: Is this is a good idea, or should I be supporting the tool tray in some other way? I've seen plenty of other benches with a center tool tray, but it's not always clear what the tray is resting on. I don't like the idea of just supporting it on the trestle bearers, since then it would be cantilevered at the ends.

Here's a picture looking from the front at the lower part of the bench:




I've got a set of long stretchers down low with a plywood shelf between them. The shelf is supported by another board glued onto the inside of the stretchers. The shelf will be two pieces of 3/4 inch plywood glued together, for a total thickness of 1.5 inches.

Above that, I've got another set of long stretchers. I got this idea from Schleining's book IIRC.

I decided not to put an apron all the way around the bench. If the apron is taller than the thickness of the top, I'm worried it will interfere with clamping stuff to the top.

Question 5: Is this wise? I've seen other benches here without an apron in front, so I'm guessing that I won't get myself into TOO much trouble with this choice. Still, I'm not sure I fully understand the tradeoffs of this particular design issue. I've seen benches with a row of what appear to be dogholes in the front apron. Is this the feature I'll be missing out on?

Here's another shot from below:




This picture shows that the dog holes miss the bearer on the right side but I still need to tweak something on the left side, since the dog holes are hitting the left bearer.

Here's a picture of part of the trestle in progress:




All the joinery in the trestle is done with mortises. The stretchers will simply be inserted into the mortises shown in the picture above. The legs, feet and bearers are 4 inches by 4 inches.

Question 6: Is this a bad idea? Is there any reason I need to actually cut tenons in the stretcher, rather than just inserting the end of the stretcher into a mortise?

I don't plan to actually cut these mortises. Rather, I plan to laminate the legs and build the mortises by simply leaving out wood when I laminate.

The following picture is a shot of the foot with mortises for the leg tenons. Unlike the stretchers, the legs will actually have tenons (built from laminating them).



Here's a shot of the completed trestle before the top goes on:



One thing I haven't figured out yet is how to attach the top slabs to the trestle bearers. I know I need to be careful about expansion of the top, I just haven't figured out exactly how I want to do this.

Question 7: Are the short stretchers overkill? I want this to be really sturdy, no racking at all, but if I'm overbuilding this to the point of absurdity, I don't mind hearing somebody say so.

Question 8: I'm planning to glue the whole trestle together. Should I not? Should I be using bolts through the mortises and stuff like that?

The final picture is a shot of the top before the endcap goes on. The tenons for the end cap are cut in the slabs, and you can see the dadoes in the inside sides of the slabs for the tray.

Question 9: Is there some better way to attach the end cap? I know I can't glue it all the across because of the cross-grain joint, but I'm open to other suggestions.

Question 10: Any other advice?

Thanks in advance!

[Roy McQuay]

Nice effort, I wish I could learn to use my design software like that. Anyway, I just wanted to suggest that when you attach the top to the base, you can use metal clips that are made for tabletops. There are different types, but all will allow for wood movement. Something of this size will definitely be moving. You can also use slotted holes and screws with washers. Depends on how you decide to attach. Wood movement is across the grain, insignificant with the grain. Good luck. Also, my opinion of dog holes is that they will be much easier to keep clear if they go all the way through. It wouldn't take very long to fill them with wood chips and sawdust.

[Dan Forman]

The only thing I feel qualified to suggest is to have your dog holes go all the way through the top so that you can use a hold fast. The dog holes in the vise don't need to go all the way through, I just use a section of dowel for the vise dog, and remove it when not needed.

I think the idea of cutting tenons into the stretchers is that the shoulder of the tenon adds strength to prevent racking.

Dan

[Mark Stutz]

Eric,
Just a couple of thoughts after my first read thru. I agree, the dog holes will fill up with chips and will be a pain to clean out...so all the way thru. I would also consider making the bottom of the too tray removable, and in several pieces. This will allow you to clamp to the bench in the middle of the bench. Put the end sections in the dadoes, but rest 2 or 3 middle sections on cleats for quick easy removal. As far as attaching the top...gravity will work just fine. Mine simply has a dowel in each trestle that fits into the mating hole in the underside of the top, to prevent it sliding off. If you ever contemplate moving...either you or the moving company will appreciate a trestle base that comes apart.
However you decide to go, good luck with the project.

Mark

[Andy Howard]

Eric,

I will try to answer your questions and give you feedback on your bench based on the fact that I built one very similar to this about 9 months ago.

1. With a 4" thick top a 16" overhang will not be a problem. I did an equal overhang on each side of my bench, but just because That Is what I wanted.

2. I drilled my dog holes all the way thru. This gives 2 advantages as I see it. Stuff will fall thru and not accumulate, and you have the option to use a holdfast. I got a pair of Gramercy holdfasts and they are wonderfull. I went with 3/4" holes, and have not regreted the decision. a 3/4' dowel and some wood scraps will make you all sorts of stops and dogs plus the veritas brass dogs and wonder dogs are 3/4" and you can get some holdfasts.

3. The holes in the vise jaws do not need to be thru holes. Drill them as deep as you like, but make sure not to hit any of your vise hardware! You wont be using holdfasts on the vise jaws, and you can clean out the few holes in the vises if needed.

4. I used the dado method to hold my tool tray, and it works great. I think 3/4" plywood is way overkill for the 8" span your tool tray will have. I have about a 5 1/2" span, and I used 1/4" plywood. The main reason I had for using thinner plywood was to preserve the depth of the tool tray. If you use a 3/4" tray bottom vs a 1/4" you loose a 1/2" of depth in the tray. I wanted to make sure some items would fit in my tray and be below the surface of the bench. Lay out some items you think you will hold in the tray and measure how high they sit, the 1/2" may matter to you, and it may not. Just something to think about.
Also, I have 2 pieces for my bottom. Makes it easier to slide out and clean when you need to.

5. I have no apron. The apron is to make up for a lack of benchtop thickness, which you will not have with a 4" top. Most benches with an apron have much thinner tops. I really like not having an apron, as it give you much more clamping flexibility.

6. I would use a tenon on the end of your stretchers.

7. In your current design I think your short stretchers are not needed. I personally think you are making the base of the bench more complicated than it needs to be, but that is just my opinion. I chose to get my legs as close to the corners as I could to help with stability, and my base has been great so far. I can barely get the thing to slide when I want to!

8. I personally glued and drawbored all my joints for the entire base on my bench. Also, my top has mortises on the bottom of it and the tops of the legs were tennoned, so those joints are also glued and drawbored. My bench is mobile, but not as seperate pieces.

9. I have a twin screw, and while you could do as you have planned, it is not necessary. The end cap with the twin screw is held on with 4 bolts and barrel nuts. I think trying to do the endcap like you have it would just lead to more difficulties.

10. Ask lots of questions, and if you have anyone around with a bench ask if you can try theirs first. I really like mine so far, and it is getting a lot of use. I think yours may be a bit high, but this is very personal. Remember, you could always make a little riser for under the legs, but it is very hard to cut all the legs once it is assembled!

And, since you asked, I will offer this last suggestion.
On my bench, I made sure to have the long stretcher relatively close to the ground. This does one major thing for me......it provides for my mobility option. If and when I want to move my bench I just lift one side up a bit and kick a furniture dolly under the middle. This gets all four legs off the ground and allows me to move it very easily. $20 to $30 will buy a nice heavy duty furniture dolly.

Here is a picture of what I made. I wasnt quite thru yet, but I do have four rows of holes on my benchtop now.



Andy

[Alan Turner]

Eric,
Andy's comments are right on target. I have two suggestions. First, consider a very short tenon on the lower stretchers, and use a through bolt and captured nut. In this way you have a bench that can be disassembled for moving, and you can tighten them if need be based upon the change in seasons, or drying of wood. I use 1/2" by 6", grade two with square nut.

Second, use a top cross stretcher attached to the leg tops with a recessed bridle joint. This is easy to cut on a table saw, is quite strong, and will let you use one lag screw on each side of the top. Easily removable. No wood movement issues.

I am not a fan of the twin screw, and prefer a traditional tail vise, but this is a matter of taste, of course.

[Jeff Johnson]

Do you want to consider capping the open end of the tool tray? It might give additional structural stiffness to the two pieces of top.

'Course - that makes it harder to clean the tool tray, but you could consider ramps in the tray to ease clean-out and avoid having to dig into the corners for small bits dropped in there.

Are the upper stretchers and the short cross-pieces structurally necessary?

[Robert Trotter]

Andy,

Looking at your bench picture am I right in that you have no top stretchers in either direction. Just four legs with botom stretchers and the legs morticed into the top? So the stability is from the mortice into the top?

It's a bit hard to see clearly but am I right in that your legs and the front of your bench are in line?

If so, how do you find this?

And... is your bench made from pine? Has it got enough weight for hand planing?

I am in the process of thinking about my bench design and construction also. I am wondering if I need the top stretchers with a thick top. If there are no stretcher at the top will the table be stable against racking?

Eric, I am thinking about the twin screw vices for my bench, too. One on the end and one as a face vice. The regular size on the end and the larger size for the front vice. I was thinking this for the front vice as I thought with the 24" centre to centre spaceing between screws it would allow me to support drawers and the like like a scandanavian shoulder vice would. Anyone's thoughts on this would be very helpful for me and maybe Eric too as he ssaid he hasn't decided on his front vice yet.

On the front vice, looking at your drawing Erice, I would suggest that you put the rear jaw of what ever vice you choose in-line with the bench. So set it back into the bench. And if you were laminating your top yourself and using the twin screw then decide and and then laminate the rear jaw into the bench or just leave a section out there so you could use the bolt system to atttach it and then you could remove it easily for maintenance or replacement.

I'll be watching others' advice since I am interested as well.

Robert

[Eric Sink]

Thanks for all the responses. I'll be making a few changes based on the feedback I have received here.

I'm looking forward to the day I can post actual photographs of the finished bench.

[Eric Sink]

Do you want to consider capping the open end of the tool tray? It might give additional structural stiffness to the two pieces of top.

I'd like to cap it, both for strength and to hide the plywood edge. But I really want the tray to be removable.

[Luke McFadden]

Thanks for all the responses. I'll be making a few changes based on the feedback I have received here.

I'm looking forward to the day I can post actual photographs of the finished bench.

I'm really interested in the changes that you make to the table via your program. So, maybe when you get to a final design, if you could post some more pictures like in your first post, that would be great!

L

[Ron Brese]

Eric I like your design. I don't think you need an apron with a 4" thick top, in fact I think you wouldn't need one with a 3" thick top. The only other thing that you may want to consider is to enclose the open area under the bench. It will afford a lot more storage and a good 3/4" back panel will make this bench like a rock. My bench is not built on a stretcher base but is based on a very strong 3/4" plywood cabinet and it is heavy and stiff. If you opt for the enclosed storage and are going to incorporate vertical support for workpieces, make sure you put this feature on the side without the doors and drawers. If you do everytime you clamp something to the side you will block your access to the tools in the storage cabinet. I know I made this mistake.

Ron

[Eric Sink]

9. I have a twin screw, and while you could do as you have planned, it is not necessary. The end cap with the twin screw is held on with 4 bolts and barrel nuts. I think trying to do the endcap like you have it would just lead to more difficulties.

Hmmm. Let's make sure I understand what you're saying:

"Don't bother with the tenon/groove joint on the endcap. Just attach the
endcap with the bolts and barrel nuts as explained in the vise instructions."

Is that right? Will that approach be safe in terms of expansion/contraction of the top?

[Eric Sink]

So, maybe when you get to a final design, if you could post some more pictures like in your first post, that would be great!

Will do. I'm making modifications to the plan now. I'll post the result when I get all the tweaks completed.

[Ruston Hughes]

First of all, very nice design. You've obviously put a lot of thought into this.

Here are a few suggestions:

1. Buy your vises before finalizing the overhand you'll use on each end. Knowing exactly what the clearance requirements are can save a few headaches.

2. As others have suggested, use a drawbore on your M&T joints. I'm sure a well executed M&T may not need the reinforcement, but I don't have enough confidence in my abilitity to execute so it seemed like easy insurance to pin the joints.

3. For the dog holes in the vise jaw, I drilled mine about 3 inches deep and then drilled a 1/2" hole through the ouside face of the jaw to the bottom of the dog hole. This allows chips and debris to be cleared easily.

Most of all, have fun building it!!