I've been working more and more with off-the-shelf 3D printers but I haven't forgotten the importance of the Reprap project. Some will say that the proliferation of inexpensive consumer-grade 3D printers are proof that the project has served its purpose and run its course, but I couldn't disagree more.
Those working on Repraps continue to push the state-of-the-art of 3D printing forward and many of the things we take for granted from off-the-shelf printers came from the continuing evolution of Reprap machines.
For my part I continue to work on my own Reprap design, SE/3D. The areas I'm seeking to improve is reducing dependencies on non-printed parts ("minerals") and integrating additional CNC processes (milling, lasering and potentially, assembly), but I'm wondering if I should be focusing elsewhere as well.
One area where I see a lot of potential is in feedstock, or the input material to the machine. Most designs assume the availability of prepared filament, but that's a risky assumption outside of major metropolitan areas or where mail-order supplies are not an option, so I've been thinking about ways to extend what a Reprap is to include accepting input material from less refined sources.
The easiest (and one we experimented with in the early days) are existing materials used for other purposes such as line trimmer ("Weed Eater") spools. I don't know exactly what this material is so there may be saftey concerns, but it's a fairly straightforward option.
Another I've seen in the last few years are machines that can "peel" a plastic bottle to turn it into a sort of ribbon that can be fed into an extruder (I'm not sure I've seen this done directly, but I think it's possible). A Reprap design that incorporated something like this could be quite amazing and would definitely expand the range of places such a machine could be operated.
The holy grail of course is a machine that can take chunks of plastic, grind them up or whatever and re-use it for input. Even if it were limited to processing plastics that are commonly used for printing (PLA for example) it would be useful in recycling cast-off failed prints or support material and would result in a lot less waste.
That last one I know folks have been working-on for a long time and at the moment I haven't seen a setup that could be tightly integrated, especially at the scale of a portable machine like the one I'm designing (of course I could have missed such a project if it's out there). So I think for my part I'm most interested in the second option, the bottle peeler.
Coincidentally this solves a couple of problems I've had with the SE/3D design. The first is: where to stick the filament spool. With a bottle peeler it feels more reasonable to just have somewhere to stick a bottle (or two?) on the outside, maybe a couple of pop-out clamps that hold the bottles?
The second has to do with hot-end/extruder selection. It's tempting to use a well-known design but to me that feels a bit like cheating (since again I'm trying to optimize for reproducability) and also my design has some special needs like interchangeable tool heads that might be better addressed with a custom hot-end design. I think that an extruder/hot-end with a design optimized for consuming bottle peels might have advantages over an off-the-shelf design.
I'd love to bring something like this to the Midwest Reprap Fest, time to figure out exactly when that is this year...
Jason J. Gullickson, 2026