Torsion box Neander bench, any ideas?

[Dan Forman]

I would like to build a bench (my first, as in I don't have a bench at all now) with neander capabilities without spending a fortune on all that maple stock. After reading about the stability of box torsion box design, it would seem that this would be a natural for such a bench. Does anyone have experience with these, or know of plans for one?

How does one achieve a dead flat top without a similar surface for reference? My concrete floor is certainly not flat. Closest thing I would have I guess is the table saw with extension, 27 x 80", would that do?

What are the "must have" features for hand work (to compliment my power tools, not to be used exclusively)?

Dan

[Steve Wargo]

You will run into a problem with the stability of your dog holes if you use a torsion box design. Aside from that, if you make the box with 4-6" square frames on the inside and double up the top, I think that you'd be well served.

[Marc Hills]

Hi Dan:

A couple of economical alternatives would be building your benchtop around a solid core door or sandwiching together 2 or 3 pieces of 3/4" MDF.

I agree with Steve that dog holes would present problems for the torsion box idea. It's not impossible to build a torsion box bench top, but it would present a lot of additional complexity.

[JayStPeter]

PWW did a pretty good bench using a three-layer BB ply top. I'm pretty sure iit is in a special issue they have/had out recently on shop projects. I think they showed how to get it flat in the original article, but I don't have the special issue to know if it is repeated.
I know others have had luck using MDF and/or solid core doors. Layers of MDF would use the same methods as the ply.

Jay

[Don Martindale]

This is long, but it's the only way I know to get in to this - http://web.archive.org/web/200112271...cts/index.html . This is a torsion box style bench that addresses the dog hole issue. It also has a cool idea for a tail vise. I've seen one from this design, & the user really thinks it's the cats' meow. I hope this helps.....don

[Don Martindale]

I can't get the link to work, so give me a few minutes to try & post back...don

[Don Martindale]

O.K. I got it to work. Check it out, it may be what you are thinking about...don

[Dan Forman]

Thanks everyone for your ideas. I was thinking of different ways to handle the bench dog issue, looks like that last one of Don's does a pretty good job of that.

Jay, I will also try to find the PWW article, should have it at the library.

Dan

[Ralph Barhorst]

David Marks made an assembly table using the torsion box technique. You can look at his design at http://www.diynet.com/diy/ww_materia...278181,00.html

[Bart Leetch]

You could also make a jig & use thick hardwood material & rout the dog holes out with a router then glue & screw a side cheek on after the routing is finished.

[Jamie Buxton]

How does one achieve a dead flat top without a similar surface for reference?

Dan

Use a stonemason's trick: crossed strings. Run strings from corner to corner to form a big X. Put spacers at the corners to get the strings up off the table. If you're really being accurate, make the spacers under the upper string taller by the diameter of the string. If the table is flat, the strings will just kiss. I've used monofilament fishing line, because it is easy to measure the diameter. I secure the strings with a nail at one end, and hang a weight at the other end. The idea for the weights is that with equal tension in the two strings will allow equal sag.

This technique is remarkably sensitive. On a 2'x7' torsion box, I could observe the effect of sliding just one standard business card under one corner of the table.

[added in edit... To be clear, you should be doing this crossed-string step just before you glue the second skin on. The partially-assembled torsion box is easy to twist. After you glue the second skin on, the torsion box will not twist -- that's the strength of the torsion box.]

[Mark Berenbrok]

I have a handout from Highland Hardware for flattening a bench with a router. It's a pretty simple setup where the router is mounted in a sled that rides on rails screwed to the sides. It works well. I used it to flatten a 25" x 72" benchtop last weekend. I couldn't find it on their website. Give me a fax # and I'll send it Monday.

[Dan Forman]

Ralph---Thanks much for the Mark's article, very helpful.

Bart---yes , a good idea.

Jamie---Another good idea, think I will save this whole thead to my tips folder.

Mark---Don't have a fax, but I seem to remember seeing something along that line in one of my mags or books, will search.

Dan

[Mike Holbrook]

and just buy a pre made bench top. Most places that sell benches will sell you a top and many sell everything you need and plans. Once you have the top you can use what ever vises, wells, dog holes and dogs etc. that strike your fancy.

Building the top is the hard part for most individuals to accomplish. Unless you have a huge planner or drum sander it is hard to achieve the results that those who have that machinery can. When I get around to building a big bench and know exactly what I want, I think I will buy a pre made top and customize it and everything else.

[Kenneth Sternberg]

I glued up 3 sheets of mdf. That is bolted on top of an aperture card filing cabinet. The filing cabinet is bolted on top of a torque box made of 2x4s and 1/2" plywood w/ 4" casters on one end and 2 trailer jacks on the other.
I put leftover hardwood flooring on top of the mdf, and a Veritas vise on the end. It is dead flat from the mdf. It is solid as a rock and stable due to the file cabinet full of stuff. It can be moved when desired by jacking up the tongue jacks. Except for the jacks and casters from Tractor Supply for maybe $60, and the file cabinet from a used office furniture store for $40, the whole thing is made of leftovers. It is also the best bench I have had in the last 50+ years. It even looks professional, which surprised me, considering I never put any thought into the looks of the thing untill I decided to glue the flooring on top.