Year: 2017

One of the big draws of using a great deal of CNC cut materials in the construction of structures has been the prospect of integrating the the interconnection of components into the components themselves. A few of the previous system attempts at building structures completely from CNC cut plywood have focused on some sort of tab principle to sidestep conventional mechanical fastening like screws or nails. This system offered by Clemson University has used something a bit different – the use of zip-ties to serve the inevitable need for fastening beyond the tab or friction-fit concept.

I’m still getting my head around the methods, processes and design elements necessary to carry this off. I’d assume that the integration of zip-tie fastening would actually be rather easy to do. Slithering plastic ties through wood components would really only require the placement of through holes at the right areas. That seems deliciously easy. In my mind, the tricky part would be to route the ties through in a manner where their best features are used in the strongest manner.

Thinking about zip ties, I’d figure that their strength lies in tensile loading and twisting forces. The weaknesses would be the fact that their flexibility would be difficult to mitigate when trying to get rigidity out of the connections. Perhaps this could be addressed in the remainder of the wood connection design where there isn’t sufficient directional latitude for the twisting to happen?

To this end, there seems to be painfully little imagery published of Clemson’s zip tie system to get an idea on how this system would be executed. Hopefully in the future, the university will mete out a bit more detail. Until then, I guess it’s back to the labs and the sketchbooks to try and arrive at how it could all work!

ArchDaily has posted a rather interesting selection of metal connectors meant for laminated wood products. At one level, the different methods are great to look at for seeing what’s available currently for such things and I’d also posit that they’re also great examples to draw from when looking into designing something a little more custom or further afield.

These 15 examples, for me, beg the question of whether there are ways where these connectors could be made with wood (engineered or otherwise) or even integrated into the laminate components themselves. Obviously this supposes that there would need to be a greater amount of fabrication per component and connector – and certainly a bit of engineering involved.

This thinking sort of dovetails with the previous post looking at how IKEA is working to reduce the overall part count and to an extent, the combination of materials and components. Perhaps the same can be done with architectural-scale projects.

Creating connectors out of wood does pose a few interesting issues, namely it would appear that most of these pictured in the article calls for bolting in two directions 90 degrees off from each other. This is a bit more complex with most wood products where grain tends to be an issue – and is certainly not the case with metals where strength is homogeneous no matter which direction.

On the surface, this table leg solution from IKEA (by way of Core77.com) seems like a pretty interesting bit of design work that reduces manufacturing and supply chain load, as the number of components are reduced (less hardware). I would also assume that they’d figured out how to make the new CNC embellishments with the same machine that would have made the parts to begin with. All wins from a production lens.

The thing that excites me about the story is that, at least in furniture design, the applications of CNC woodworking are moving from shape-cutting into interlocking joinery of a much more complex definition. Thinking like IKEA is moves us past the general “tab-slot” thinking (and even conventional woodworking joinery) and into more of a “machine component” sort of design methodology. It’s fun to think about other applications that will develop in the future when this becomes more common.