Hello World! / Soluble Support Aug 26 2013
It's been an exciting week. We've heard from all sorts of interesting people and organizations from all around the world, working on all manner of awesome projects. We've heard from architects, engineers, designers, artists, artisans, makers, educators, and entrepreneurs. We are humbled to be able to provide a machine that can facilitate such a broad and fascinating range of human endeavor.
We're starting this blog so that we can keep people posted on the latest developments and so that we can explain some of the engineering behind the Isis One for the benefit of the open source community at large. In the coming weeks we'll discuss our bed leveling system, how we got prints to stick reliably to the bed, why we like PLA so much, and why we think our linear systems are so great. But first we want to talk about support material.
In the past week, we've gotten a number of sample parts to print from prospective customers. Although for the most part our prototype Isis Ones are doing an admirable job, one problem has become clear: support material. Our KISSlicer-generated breakaway support makes use of a gap—0.5 mm by default—between the support interface layer and the supported surface. This is, on the whole, a pretty effective method, allowing for relatively easy removal. It is ideally supported to prints like Michelangelo's David, who's elbow and chin need just a touch of support, and it also works pretty well for prints like the velociraptor skull, although in this case support removal took a solid half hour. It's a huge improvement on the status quo of no support material at all. But for a number of the sample prints people have been sending us—curvy sorts of things with large supported areas—it's appearing to be inadequate, requiring too much effort to remove and leaving a messy surface.
This isn't good enough for us, so here's the plan: we're going to have a shot at making soluble support work over the next three weeks. If we can pull it off, we'll ship the new dual extruder Isis One at no additional cost for all pre-orders. Those of you who've already bought an Isis One will have the dual version free of charge, or keep the original design as ordered. We hope the new soluble support design will be hugely helpful to our customers and can set the new standard for extrusion-based printers.
The design we have in mind involves a single hotend of a novel design, featuring two separate nozzle orifices a few millimeters apart in the same heater block. The support material used will be polyvinyl alcohol (PVA), which melts in a similar range to PLA, dissolves in water, and is nontoxic. Rather than removing support material manually, you'll simply take the print off the bed and soak it overnight in a bucket of water, in which the support material will dissolve. This will allow us to omit the support gap, allowing perfect supported surfaces and much more elaborate supported prints. Eventually, when we get the software updated, you'll even be able to print complex mechanical systems at once, the moving parts separated by thin layers of PVA.
Helping us with this new endeavor will be a newly hired mechanical engineer named Megan and a beastly new lathe (yet to be named)*. Megan met Marc a year ago on the BJ Scav team, where they worked together on item #111, for which they built a fully automatic pipette tip machine gun.
Stay tuned. This will be interesting, and updates will be available here.
That's all for now, Team Isis3D
*Update: The lathe has been named Rosie. :)