DURR: The shell

Posted in Manufacturing , on Monday, November 11

We have a few hundred iterations on the casing. But mainly, we used our Makerbot for rough estimates on height and diameter, and tried a few different moulds for stability and materiality, before ordering accurate test samples from Shapeways.

Same with the strap fasteners, we went back and forth on standard watch-fasteners, button studs and custom-designed friction-fasteners.
We ended up with the self-made friction-fasteners.

We decided to use the strap itself as a back-cover, to keep the amount of parts down.

When we found the perfect dimensions at last, we had decided to make 50 pieces to test if there is a market.
With that low a volume we figured we could order them from Shapeways and dye them ourselves:

We used dye from Rit, after reading this post from Colleen Jordan at Wearable planters.

What we learnt from this is more interesting than photos of the process.

In every step of the way we encountered problems. Every article you read online about manufacturing says that you can't underestimate the amount of time manufacturing takes, and our case was no exception. What might differ though, is that we've done EVERYTHING ourselves, so if and when we go bigger, we know where we are likely to meet problems. Yes' it's taken a huge amount of time, but we haven't spent an enormous amount of money.

We've had to manually glue a small attachment to every button because of a misalignment, test-dye each sample a dozen times to find the correct shade, and calibrate each single IC because of an inconsistent timer circuit. If we'd had a large manufacturing scheme from the beginning we'd be screwed.

One of our principles is that we want no investors, be it the VC-kind, angels or crowd-sourced. We'll bootstrap everything, and if we can't afford big-scale things, we'll do it small. This means we don't owe anyone anything, but it also means we can't afford high-volume manufacturing. As a consequence, every added component challenged our ability to afford making DURR at all. When we do small-scale we don't get the same high-volume discounts as bigger companies. So we had to keep the component-count low, and tweak what we had to fit. All in all, we ended up having 15 components, and that's not just the electronic components, that's also including the leather strap, both the strap fasteners and the casing.

---