The last three days marked the 2018 Midwest RepRap Festival. Every year, the stars of the 3D printing world make it out to Goshen, Indiana for the greatest gathering of 3D printers and printing enthusiasts the world has ever seen. This isn’t like any other 3D printing convention — everyone here needs to take the time to get to Goshen, and that means only the people who want to be here make it out.

Over the weekend we covered some amazing hacks and printer builds from MRRF. The ‘BeagleBone On A Chip’ has become a complete solution for a 3D printer controller. This is a great development that takes advantage of the very under-used Programmable Real-Time Units found in the BeagleBone, and will make an excellent controller for that custom printer you’ve been wanting to build. E3D has announced they’re working on an automatic tool-changing printer. It’s a slight derivative of their now-defunct BigBox printer, but is quite possibly the best answer to multi-material filament printers we’ve ever seen. There’s some interest from the community, and if everything goes well, this printer may become a kit, or something of the sort. Filament splicing robots also made an appearance at this year’s MRRF, and the results are extremely impressive. Now you can create multi-color prints with the printer you already own. Is it expensive? Yes, but it looks so good.

This wasn’t all that could be found at MRRF. There were hundreds of printers at the event, and at last count, over 1300 attendees. That’s amazing for a 3D printer convention that is held every year in the middle of nowhere, Indiana. What were the coolest sights and sounds coming out of MRRF this year? Check out the best-of list below.

Glitter Printers

MRRF had a 30-foot-tall delta printer. MRRF had the latest products and projects from the best 3D printing companies out there. There was an R2D2. The star of the show, though, was the glitter printer.

[Scott Ziv] got his hands on a Z Corp Z402 printer through some means or another. This is an ancient 3D printer from the early 2000s prints using a powder by usingan inkjet-like device to dispense a binding agent to hold it together. [Scott] didn’t want to buy the powder and binder, so he simply mounted a laser diode to the carriage and tried to melt some powder. Sugar didn’t quite work, but he did have success in an unlikely place: glitter. Yes, glitter. The stuff that kills dolphins.

[Scott] found a guy selling a few buckets of glitter for about a dollar a pound. This glitter is mostly PLA PET, surprisingly, with a little bit of aluminum and some polyester in there as well. It melted well with the diode laser, although the parts produced crumble to bits if they’re moved at all. [Scott] encased his best prints in epoxy resin, and while it’s not something that can create functional prints, it is a printer that prints in glitter.

The writeup for this build will eventually be documented on [Scott]’s website.

Pellet Extruders

If you’re building a big printer, you’re going to need a lot of plastic. Standard 1kg spools are great if your printer fits on a desk, but for those massive build volume printers, filament just becomes too expensive. The better way is pellets, the raw material of the plastic world. Do this, though, and you need a way to extrude and melt those pellets.

[haqnmaq] has created a pellet extruder for large-format printers, capable of printing very large objects with very cheap plastic. The key component of anything that extrudes pellets is the auger; commercial, industrial injection molders use very clever and very expensive augers, but [haq] is using a standard, off-the-shelf 1/2″ wood auger for this build. This drill bit is driven by a NEMA 23 motor with a 47:1 gearbox, and the heat comes from two 300W heater bands.

This project is on Hackaday.io, you can check that out here. [haqnmaq] is extruding plastic with it, now the only thing left to do is to mount it to a printer.

Prusa’s Latest Triumph

A while ago, Prusa introduced the multi-extrusion upgrade to the Prusa i3. It works, but there is a downside — each filament you want to multi-extrude requires a separate stepper motor. If you want four colors of filament, that’s four motors.

There’s a better way of doing things. It was announced a few weeks ago, but at MRRF we got our first look at the new multimaterial upgrade. Instead of a stepper for each different filament, this is a weird little machine that takes five filaments, selects one, and pushes it into the extruder motor on the x-carriage.

Here’s what’s going on with this new extruder. The ‘filament selector box’ — or whatever we’re calling it — consists of five holes in the back that accept different filaments, and a single hole on the front that accepts PTFE tubing that feeds right into the main extruder on the x-carriage. In between the front and the back, the filament feeds through a series of rollers that selectively feed filament to the front. When the printer wants to change filament, the movable carriage on the front moves from one output to the other. Filament is automatically sliced inside the machine. Think of it as a printer-mounted version of the filament-slicing robots we saw this weekend, only very much cheaper and significantly more clever.

The entire contraption is driven by a small board with three motor drivers. This is the Prusaino, and will make a great CNC controller when it’s sold by itself.

This is a fantastic advancement in the state of multimaterial printing. It’s not shipping yet, but we can’t wait to get our hands on this thing.

Infinite Build Volume Printers and Hurdy Gurdies

Last year, the best thing at MRRF, and possibly the greatest 3D printing innovation of the year, was the infinite build volume printer. What makes this an infinite build volume printer? It can print a beam that’s about six inches wide, six inches tall, and millions of miles long. You supply the plastic, power, and time. It’s absurdly clever, another company quickly released their plans for one, and [Brook] of Printrbot connected with [Bill Steele], the guy at MRRF with the prototype, to create a slightly more professional-looking version.

This year, that prototype made it out to MRRF. It works, and it was printing off tiny little models of airplanes.

There are a few things going on with this printer that aren’t readily apparent. Only the first few inches of that kapton bed are heated. This makes sense; the printer really only prints on the first few millimeters of the bed, anyway. By not heating the end of the bed, the prints pop right off. There are a few issues with the bed wandering off to one side, but future versions will have a 1mm crown on the rollers, keeping the bed centered. [Bill] is using a Raspberry Pi to queue up his models and have everything slide off the printer. He took this machine to Oshkosh a while ago, and printed 1,500 of those little planes in a weekend. It’s a great machine and we can’t wait to see this thing make it into production.

Want something strange and weird? Here’s a hurdy gurdy:

What’s a hurdy gurdy? String bagpipes. That’s what it sounds like, at least. This hurdy gurdy has a pair of strings that are played with keys (giving you a specific note), and two drone strings that… drone. Turn a crank, which turns a wheel, which vibrates strings. Yeah, it’s slightly weird and sounds like string bagpipes.

This hurdy gurdy was a kit made of wood, and the wheel for these is usually made out of maple. Here, the wheel is constructed out of red PLA for the structure, and a thin band of carbon fibre filament on the rim. It works well enough, although how it sounds is greatly dependent on the listener.

High Metal Content Filament

Metal filament, or PLA that has a bit of tiny metal particles embedded inside, has been around for a while. If your prints are very good, you can smooth them to a high shine. The metal content of these filaments hover around 60-70%. It’s good, it’s heavy, but here’s some filament with a metal content of 80%. Yes, there is a difference, and this filament is worth the price.

This filament comes from The Virtual Foundry, and pictures will never do it justice. This feels like real metal. It is as if these objects were cast in bronze and plated with copper or stainless steel. The specs for the 316L Stainless filament give it a density of 4.05, a metal content of 81%, and it prints well at 210C. This is the greatest metal filament I’ve ever seen, and if you throw an object printed in this into a kiln, it comes out as a solid metal object.

How much does it cost? $100 for a kilogram of the copper filament. Keep in mind it’s significantly heavier than regular ‘ol PLA.

Can’t Wait Till Next Year

MRRF is simply the greatest 3D printing convention on the planet. Everyone who is there wants to be there. Everyone has awesome stuff to show off. This is where the future of 3D printing is on display, and it’s all happening in Goshen, Indiana, a town whose WalMart has a hitch for horse and buggies. No, we can’t explain it, but we’re going again next year.