There’s more than just 0’s and 1’s

A journey from analog to digital, ending somewhere in the middle.

Fabricating a“doorble” table leg

My life becomes digital

For the first half of my working life I was a boat carpenter, one of the most traditional and analog ways to make a living. My shop looked like every other woodworker’s shop with walls covered in patterns and templates for the bits and pieces of boats that I had to duplicate on a regular basis. Cutouts for inspection ports, templates for deck beams and ribs, and a myriad of other weird shapes.

The process for making these patterns was pretty much the same every time…start by rough cutting the template with a bandsaw or jigsaw and then use hand planes along with files, rasps, and assorted sanders to make them as accurate as possible. If the shape of a part was critical, maybe two parts that had to fit together precisely, then it sometimes took all day and a couple of tries to get it just right. Lots of patterns ended up in the trash when a little too much was taken off.

If I was lucky when a new part was needed I would have already made a template for it and would pull it off the wall and use a saw to cut my blank close to the correct shape. Then attach the template to this rough-cut blank and use a hand router set up as a trimmer to accurately duplicate the part. This duplication technique didn’t require much skill, but creating the original template was difficult and took a long time. Larger shops had an industrial tool to do this duplicating called a pin router, and the person that created accurate templates for it was a skilled craftsman.

When affordable CAD software became available…DOS back then… and affordable CNC tools from ShopBot became available, cutting out these funky shapes became a lot easier. The CAD software let me draw things with much more accuracy than I ever could by hand, and easily make changes and modifications. The ShopBot CNC machine could cut as many parts as I wanted with much greater precision than ever before. The patterns on the wall started gathering dust.

Shelter 2.0 in Haiti

Growing the Shelter 2.0 project

For years my long-time Shelter 2.0 collaborator Robert Bridges and I have been shipping Shelter kits all over. It was designed for efficient CNC cutting, but we kept struggling with the same problem. We make the CNC files available online so that anyone can cut them, and many have been built from those files, but fabricating them requires a CNC machine. We can easily cut Shelter kits in our shops in Virginia and ship them anywhere they were needed in the world, but that adds a lot to their cost both in money and in the environmental impacts of shipping.

The other option is to ship CNC machines to the area where the Shelters were needed and they could be cut on site, in the process teaching new skills that would transfer to other products. Unfortunately both of these options have some potential problems.

Enough equipment to setup a shop can be expensive to purchase and ship when a disaster hits. Cutting the structures somewhere else and shipping them to where they’re needed is slow and costly, or requires stockpiling large numbers which ties up money desperately needed elsewhere. When a disaster strikes, adding the requirement of setting up a shop with suitable power and security and then teaching someone to run the equipment on short notice is problematic at best.

Shelter 2.0 built from construction lumber using these techniques

Combining digital and analog

Like many other things, the Shelter 2.0 design requires multiple copies of a small number of unique pieces. The trick is to be able to duplicate those accurate copies without having to CNC cut every one of them, while still maintaining something close to the precision of the original CNC cut parts.

That’s exactly how it worked when things were strictly analog. CNC cutting the original patterns would solve the biggest problem and give us the accuracy that we struggled with when hand making templates…digital design and fabrication shines for jobs like that. Once these accurate patterns have been created though, anyone can duplicate them with easily available hand power tools… basic sweat equity. Use precise digital technology for the part of the job where it’s needed, and manual hand tools for the analog duplication steps.

Over the years Robert and I have worked on quite a few innovative CNC-fabricated house prototypes, and in spite of how careful we and the designers had been, once we started to assemble the structure we would often find at least one missing slot or even a whole part that required onsite fabrication. We’ve never had a CNC machine with us but always seem to have a hand router, and have successfully used this duplication technique to copy a whole part on the job using an existing part as the template, or just add a missing slot, dogbone, or some other feature.

What are the benefits on a large scale?

So we know that this works really well occasionally for duplicating a single missing part or feature…we do it all the time… but does it make sense as a manufacturing technique? Here’s why we think it does:

  • The template files are digital, so CNC-cut patterns can be machined locally…maybe in a FabLab…or shipped from a remote location. A set of patterns is a much smaller package to transport and one that only needs to be done once for any project
  • Once the CNC cut digital patterns are at the build site, traditional hand power tools that many people are already used to working with (drills, jig saws, and hand-held routers) are used to accurately make the required parts using those patterns. The techniques needed can be learned quickly, with most of the knowledge needed and all of the precision built into the digital pattern
  • It can expand as needed. Since analog copies of the CNC-cut patterns can be functionally exact copies of the original CNC cut patterns, a set can be used to seed groups working in parallel or in other areas. You can increase the number of parts you can produce by simply duplicating the templates onsite and adding more people and hand tools…a new build team
  • It’s easy to “backup”. A copy of the original set of template can be created and used as the working set, saving the original set as a backup
  • It can work with materials that are hard to CNC cut. Standard construction plywood can be a warped “potato chip” and problematic for CNC cutting…it would work just fine for this. It can also often utilize scrap or even locally milled lumber.
Template on the blank

When does this analog/digital hybrid work the best?

  • When there’s a limited number of unique parts in a design, but several copies of each are needed
  • When the parts require mostly 2d outline cutting, although some 3d features like pockets are certainly possible
  • When there is an excess of available labor. The process can branch and grow as extra labor becomes available
  • Areas with poor security and electrical infrastructure are problematic for setting up production shops, especially with digital technology. All the tools needed for this hybrid system are small, can be powered by a small generator or solar panels, and can be locked in a closet or secure toolbox.
  • When the design was initially created to be somewhat “material agnostic”, allowing the use of a wide range of materials. See my rant on the ShopBot blog about plywood for thoughts on this
  • When you don’t need absolute precision, or don’t mind a couple of screw holes on your parts. If you’re making artificial heart valves, this technique is definitely not for you!

Not every technique works for all cases and this one is no different. There are lots of amazing projects and designs that are only possible using digital fabrication tools from start to finish, but there are others where using a similar combination of digital and analog techniques makes a lot of sense. Although we originally became interested in this technique for fabricating Shelter 2.0 in sub-optimal conditions, we’ve begun exploring the potential for fabricating all sorts of products where a CNC machine might not be available.

Finished table leg

I’m still incredibly passionate about the potential that Digital Fabrication, especially CNC routing, has for revolutionizing the way that much of the things in our lives are made. If you already have access to a CNC machine, put it to work! But if not maybe this digital/analog hybrid system is worth a look.