When assembling projects, nothing beats a wide and spacious dead flat surface. And one of the easiest and most efficient ways to create a dead flat surface is by constructing what is known as a torsion box. A torsion box is really nothing more than a grid-work with a skin on both sides. This creates a very strong, yet light, structure that resists warping and sagging. Its very similar to the concept behind an airplane wing. This episode covers the construction of the Torsion Box top and Episode 19 covers the construction of the base.
Build Along!
If you plan on building this project, this exploded diagram will give you the measurements you need to get the job done. A Sketchup file of this project is also available, thanks to Chris Williams.
Want This Project on DVD?
This series is now available on DVD. Purchase your copy today!
Marc,
I am about to tackle this challenge of the table. Thanks for the great videos and putting this out there. I am just starting in the hobby and still figuring a lot out!
My question concern is this….
I understand using the saw horses, shims, etc… to get the table flat dead flat. My next concern is how to get the base dead flat. My garage floor is not level.. I was hoping to use heavy duty casters, but I wouldn’t be able to level the base. Is it is just important to get my base perfectly level? Or with the torsion box being dead flat all I need. Any help would be appreciated. I have also thought of using heavy duty leveling feet.
Thanks
I suppose if the base is not dead flat, it could pull the torsion box out of flat over time. But one thing you might do is get the base in position and either level it, or ship that gaps that exist between the torsion box and the top of the base. The problem here is that you want things to be mobile. If that’s the case, then there really isn’t a whole lot you can do. If the unit is in a different location periodically, you’re just going to have to roll with the punches and hope everything stays flat over time. How much actual impact you’ll see in the flatness of the top is something that I can’t even begin to predict. It might be an issue and it might not. But I would just make an effort to ensure there are no gaps between your base and the torsion box and you’ll probably be ok.
Great video. Just wanted to ask, is there any particular reason you couldn’t true up the new assembly table base and use that vs. the saw horses?
Nope. If you can make it dead flat and stable, it would work just fine for this purpose.
I started making my grid today. I got as far as starting my second row when I found that my brad nailer (which I bought just for this project) is simply too big to fit in the 7.25″ grid spaces. Oops! I then went back to the video and observed a funny thing. Notice the tool change that occurs just as second row is started (@13:35). You are one sly devil Marc.
Brilliant video and great informative explanation …I am making one !….just one point, you need to get a dustmask for your step dad…you may need him for the next project ! LOL thanks again I am a fan from the UK. Geoff
Marc,
Thanks for the assembly table design, it is just what I needed as I am about to start building a full set of kitchen cabinets (my first real wood project). I built the torsion box, and although I did have problems with toenailing the grid it came out perfect – dead flat everywhere to within .002″. However I might have made a mistake when I chose to use the waxed mdf support sheet as the top skin. I was thinking I would just use it “as is” and apply more wax, but now I want a more durable surface.
The options I could think of are:
a) plastic laminate, but I am not sure if the contact adhesive will stick to the “thoroughly” waxed mdf… and I don’t know how I could remove the wax.
b) sand the surface a bit and the use poy/varnish mixture – again I don’t know if the wax will cause issues
c) use a harboard top the way you did it. Problem here is I don’t know how to get the screws flush with the top. I experimented with some scrap and I can’t get a good accurate countersink in the harboard, not to mention screwing into MDF; using fine-thread drywall screws seems to be the best bet, but still not perfect. Also, the hardboard I have does not lay flat, I would need a lot of screws. Maybe the type of harboard I have is not the same as yours – mine is like pegboard material 1/8″ think. What did you use?
Any suggestions on the best way to deal with the top skin will be most welcome; everything else is on hold until I finish it :)
Thanks agian for a great article/video
Hi Marc,
I just wanted to say that I just built this torsion box table over the last couple weeks and it turned out great! I doubled this as an out-feed table for my table saw and had to make a few modifications. But overall, it is outstanding!
Thanks!
Justin
Hi Marc,
Love your series. You and Norm Abram rule.
Question about your torsion box. Is there any reason one shouldn’t just half-joint a bunch of boards to form the internal structure rather than glue and nail the individual spacers?
I’m very new to wood working so pardon my ignorance.
Cheers,
Steve
Thanks very much Steve. You can certainly do that. In fact, its probably the most suggested change from the original concept so I know numerous folks have done it successfully.
Well, I spent my July 4th weekend building the base cabinet (san drawers and doors) and most of the torsion box. I just don’t have the energy to try to flip that over.
My biggest issue with the box (other than cutting the grid pieces to 7 1/8 instead of 7 1/4) was getting the brad nails in the pieces. You just “toed” in the nails. I found this almost impossible. Maybe my Porter Cable brad nailer is too big, but I couldn’t hold the piece straight when I pressed the nailer to get it to fire. And many times, because of the angle, the nail hit the cross piece and skewed off to the side. The pieces, then, werent 90*, but skewed out a bit. I couldn’t figure out how to get it right. But I was able to hold them straight when I nailed in the cross pieces. I ended up with an ugly grid, but the skin I put on seems flat.
All in all, a good day in the shop.
Happy 4th.
Marc,
Learned this trick from a fellow much more experience and way smarter than I am. Who knows, he may have stolen it from someone else!
After you shim the legs of the sawhorses as a level construction base, slop some of that putty or caulk you have laying around the shop over the sawhorse legs, shims and even the floor. It may prevent a clumsy footed builder from knocking the carefully inserted shims from flying across the shop floor and save the delicate ears of any innocent bystanders.
Just don’t use anything you’ll have trouble scraping off the floor when that part of the project is finished.
Beau
This my be a dumb question, but that’s never stopped me before. Any reason not to build the base first and build the torsion box on top? With the leveled 2 x 4s to ensure flatness.
Ghana as always.
David
Nope! :)
I’m building one of these workbenches for one of my small CNC routers. Thanks for the great video and Sketchup files. I’ll use my big CNC to cut some of the parts for me…..heck I might even build a big workbench and repurpose some of the 3030 and 1530 extruded aluminum 8020 into yet another CNC…
Came across this yesterday. Great presentation. I get so tired of having doors come out twisted. I have been using a piece of ply between two sawhorses, nothing true or flat with them. This will give me something that I can count on as being flat so I can make sure my construction is true.
Thanks again for a great video.
Ken
Marc,
Thanks for the excellent video! I’ve watched it several times now and plan to get started on my table this week. However, there is one thing that kills me every time I watch this video… Why did you start out by destroying that great table you had? Being the celebrity you are I’m sure you could have got a pretty penny for off eBay or maybe even given it to your father-in-law ;) It would have been nice to have around later in the video when you were putting the plywood on top of your saw. I’m just seeing things through the eyes of someone who is putting plywood on top of a saw regularly…
Thanks again!
Ian
Hmm, well all I can say is I’m an “out with the old, in with the new” kinda guy. Even if its not the most sensible thing to do. :)
Hi Marc,
I’ve followed both videos about the Torsion box.
As it seems a good tool to assemble wood, I don’t have enought room to fit it in my workshop.
I read on some french forums that the first project a new woodworker should be is the workbench: I’ve seen many workbenches, and I think it’s a good starting point.
Do you agree with this, or do you think that the assembly table is more important than a good workbench ?
Should I make a slightly bigger (more large) workbench instead of a workbench plus an assembly table ?
Regards
Hi Ludovic. While I do think a workbench is a good project, I also think its one that is better off being made later in your career. The reason is because workbenches can be designed with all kinds of great features and options. But you don’t know what you are going to need just yet. So to get the most out of your workbench, I actually think its best to wait until you really know your needs as a woodworker. For instance, if you get more into hand tools as you progress, you are going to need a more versatile workbench. If you plan on using a lot of power tools, you won’t need nearly as complex of a setup.
That said, you do need some sort of workbench. So I would say it might be a good idea to build a quick bench using a few layers of plywood for the top, wrapped in solid wood. Then attach a nice little quick release vise and make a stable base. But don’t go overboard. Use inexpensive materials so you don’t have a lot invested in it. You might wind up trashing it later or just recycling the parts. Then start building and start using the bench. After a year or two, you’ll have a much better idea of what you need for your bench, and where this temporary one falls short. Use that knowledge to build the bench that will be with your for life.
As for the assembly table, I really consider it to be a separate tool. You can indeed build your bench wider or you can simply drop a piece of ply on top of you bench during assemblies. You don’t absolutely have to have both.