I recently stumbled across this new structural joint in an article on a design blog I follow. It wasn't entirely clear to me how it worked so I decided to try to build it. 

It should be noted that the creator Dror Benshetrit retains all legal rights to the idea. The articles say he plans to open source it for use in developing countries, but other commercial uses must be licensed. I reverse engineered a version from frames in the video, although it's close, it's not the proper ratios/dimensions. I did it to get a feel for the concept, and I share it here for the same reason. I don't have a commercial application for it at this time, and if/when I do, I will seek the proper licensing.

Step 1: Cut a strip of wood

I used 1/4" MDF which seemed proportional to the dimensions I chose of 3" x 2.25".

The first step is to set your saw to a 15 degree tilt. I used a magnetic gauge for this. It's 1 degree off in the photo because the teeth on the blade cause the gauge to sit at a 1 degree angle so I adjusted accordingly.

Next, I set my fence to 3" because I had already cut some off the material so it already had one 15 degree edge on it. If you're starting with a fresh piece, set it to 3.5", cut it, then set it to 3" and cut the other edge.

The goal is to have both sides at the same 15 degree angle as shown in the last photo.
skps files provided at dendroica.com: http://www.dendroica.com/woodworking/projects/quaDror.html
Awesome details! Thanks for sharing.
this is great. I was wondering if you have the plans for the other piece he has in relation to the quadror. In one the videos off the site he is using 2 pieces to make a table. <br>
You beat me to this! I attempted to make one the other night but realized my geometry was flawed and stopped after cutting only four pieces to go back and review Dror's vids. I think the collapsed shape is a rhombus. You'll never get all the corners to come together w/ 90 degree angles. It's like the tip of a shallow pyramid. I'll try to attach a screencap from the construction vid. The original &quot;frame&quot; of the sketch on http://www.quadror.com/about-quadror/ also displays the shape of the basic piece with an acute angle. At first I thought it was just perspective in the drawing, now I think it's more likely just the shape of the thing.
Hmm.. so you're thinking they're not square? I hadn't considered that, but it might make sense. On the quadror.com site, there are videos of actual assembly, but they're pretty small. <br><br>My first attempt I had the cuts on the inner cutout backwards so it didn't work. One of the keys is when it's open, it creates a flat surface on the table and mine didn't do that. <br><br>My second attempt was right, but I hadn't taken into account the kerf of the blade when I cut the middles out so there was a large space in the middle which didn't give it the support it should have. <br><br>I tweaked the sizes slightly in the final batch to get the middle right and the keep the &quot;legs&quot; from sticking out past the edge of the assembled square. I built mine on a 0.75&quot; grid basically. I'm not sure it's the right proportions.
This forum has other pictures:<a href="http://festoolownersgroup.com/member-projects/would-like-to-build-some-quadror-joints/">http://festoolownersgroup.com/member-projects/would-like-to-build-some-quadror-joints/</a><br> It is difficult to see but Jimbo's guess seems right.<br> Nice job anyway.<br>
Artifacture: Thanks for posting this. I was trying to make some from the video and couldn't do it until I read your instructions.<br><br>The patent application says that the blocks can be square or parallelograms depending on the application. I don't think squareness is the problem here. I'm tinkering with some improvements - namely it says the saw angles can be from 0-15, so maybe 10 or 12 degrees would be a bit more stable. Also, the application claims that the ratios of the side lengths (wrt the shortest) should be 2, 2, 2, 3, 4 exactly, although I think two of those shouldn't effect the stability of the joint (just make the pieces extent past eachother.
The specifics are in the patent for the QuaDror:<br><br>http://www.google.com/patents?id=3o3VAAAAEBAJ&amp;printsec=abstract&amp;zoom=4#v=onepage&amp;q&amp;f=false<br><br>-S.
You have to reverse them on the 6th step, then it will fit
This is a very very very interesting thingy :)
I agree with NachoMahma
. Very interesting

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Bio: Artifacture Studios is a custom design and fabrication shop that exists to explore the technical and logical limits of materials and processes. We are dedicated ... More »
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