The 3D Printer Packing Problem

Form Labs recently announced the launch of the Fuse 1, a desktop SLS printer that will print all your parts using nylon powder and a laser. This a fundamentally different method of 3D printing as compared to filament-based machines, and the best way to use a Fuse 1 is to fill the entire volume of the machine with 3D printed parts. [Michael Fogelman] decided to investigate the 3D packing problem, and managed to fill this printer with the maximum number of 3D printed tugboats. If you’re wondering, it’s 113, as compared with 82 tiny Benchies using naive bin packing.

The formal definition of this sort of problem is the bin packing problem, or simply calculating the maximum number of items can be packed into a finite volume. There is no general solution to this problem, and it’s probably impossible to create an algorithm that will solve this problem for any collection of 3D models. Nevertheless, it’s possible to create a solution that shows marked improvement over a naive solution.

[Michael]’s solution involves simulated annealing. This algorithm begins by randomly placing tugboats, then mutating the position or rotation of one of the boats for each iteration. The code is less than 1000 lines of Go and is available on GitHub if you already have an SLS printer at your disposal.

It should be noted this type of problem isn’t particularly new to the world of 3D printers. There have been a few tools to solve the bin-packing problem for filament-based printers, but the solutions to these problems are two-dimensional; since filling a bed is a problem that only uses the ‘shadow’ of the Z-axis of each part, it’s a slightly easier problem to solve.

Now that Form Labs’ Fuse 1 SLS printer has been announced, there is a new application for this type of problem in the space of 3D printers. It’s not a perfect solution — and it’s doubtful there will ever be a perfect solution — but if you’re looking for a way to fill the volume of your powder printer with parts, this is the best you’re going to do.

Turn Your Laser Cutter Into An SLS 3D Printer

Filament style 3D printers are great, but typically are rather size limited. Laser sintering printers offer huge print beds, but also come with quarter million dollar price tags. What are we supposed to do? Well, thanks to OpenSLS, it might just be possible to turn your laser cutter into your very own SLS 3D printer.

We’ve covered OpenSLS a few times before, but it looks like it’s finally becoming a more polished (and usable) solution. A research article was just recently published on the Open-Source Selective Laser Sintering (OpenSLS0 of Nylon and Biocompatible Polycaprolactone (PDF) that goes over the design and construction of a powder handling module that drops right into a laser cutter.

The team has created the hardware to turn a laser cutter with a bed size of 60cm x 90cm into an SLS printer. The beauty? The majority of the hardware is laser cut which means you already have the means to convert your laser cutter into a 3D printer.

The design files are available on their GitHub. Hardware will likely cost you around $2000, which is peanuts compared to the commercial laser sintering printers. There is tons of info in their article — too much for us to cover in a single post. If you end up building one, please let us know!

The Beginning Of The Age Of 3D Resin Printers


For several years now, filament-based plastic printers have ruled the hobbyist market, with a new iteration on squirting plastic appearing on Kickstarter every week. SLA printers, with their higher resolution and historically higher price for raw materials, have sat in the background, waiting for their time to come.

Now, with the Sedgwick printer now available on Kickstarter, we may finally be seeing some resin printers make their way into hackerspaces and workshops the world over. Instead of other DLP projector-based resin printer where projector light shines up through the resin tank, the creator of the Sedgwick, [Ron Light] is doing things the old-fashioned way: shining the projector down onto the surface of the resin. He says it’s a simpler method, and given he’s able to ship a Sedgwick kit minus the projector for $600, he might be on to something.

There are a few other resin printers coming on the scene – the LittleSLA will soon see its own Kickstarter, the mUVe 1 is already shipping, and over on Hackaday Projects, the OpenExposer project is coming along nicely. All very good news for anyone who wants higher quality prints easily.