Prusa CORE One+ INDX review: Time for a 'Tool' change

The Prusa INDX is a revolutionary new toolchanger capable of printing up to eight colors of various materials. INDX stands for Induction Dynamic Extruder, with each slim toolhead having no moving parts, just a nozzle and filament path. The extruder, or “smart head,” does all the work.

INDX is a collaborative project between Prusa Research and Bondtech. Prusa makes the platform, in this case a CORE One+ Gen 2, while Bondtech produces the toolhead system. The two companies have a long history of working together, going back to 2017’s MK3 bedslinger. The INDX can also be purchased separately on Bondtech’s site as a DIY kit to be mounted on any open-source 3D printer you feel like modding.

There are definite advantages of going with the Prusa INDX. You can buy it ready to roll, premounted on CORE One that’s ready to print ten minutes after removing it from the box. Even purchasing it as a kit from Prusa removes a lot of hassle and headache, as the kit is custom-fitted to CORE One, with all the wiring, programming, and whatnot done for you.

Sorting through the website to figure out what combination of kit and printer you need is the hardest part of the INDX experience. If you already have a CORE One, prices start at $749 for a four-color INDX “conversion” kit. Prusa optimistically says the kit takes 5 to 6 hours to install, but it took me the better part of a weekend to disassemble my machine and rebuild it as an INDX when I tested out the early Founder’s Edition.

The Prusa INDX is the first multicolor 3D printer to ditch the prime tower, making it practically waste-free. While all toolchangers can seriously cut down on wasted material by virtue of having a nozzle for each color, they still need to “prime” the nozzles before printing. This priming creates a tower of wasted material. Prusa has circumvented the prime tower with a new wiper mechanism that quickly shoots out a tiny blob of filament that’s about 13 milligrams in size – smaller than a grain of rice.

In my testing, I found the Prusa INDX was faster and less wasteful than any other toolchanger in the workshop. I ran the same model with similar settings on both the Prusa INDX and the Bambu Lab H2C, the closest machine to a toolchanger that Bambu currently has in production. The INDX was able to run it nearly nine hours faster, with 83.58 grams less wasted material (not counting supports) and 3 more colors.

The CORE One+ INDX starts at $1,699 for a DIY kit with four toolheads and goes up to $2,119 for an assembled 3D printer with eight toolheads, plus a Buddy Cam and Advanced filtration. If you already have the printer, the conversion kit is $749 for four toolheads and $999 for eight. There is no pricing for individual toolheads at the moment, but you can start with four toolheads and later add more. Individual tools are currently $45 on the Bondtech website.

The Prusa CORE One+ INDX lives up to its reputation and is one of the best 3D printers we’ve tested to date.

Specifications

Prusa CORE One+ INDX: Included in the Box

The Prusa CORE One+ INDX we received was pre-assembled and included eight toolheads. It only needed to be unpacked, have its screen mounted, then snap on the spool holders and Bowden tubes. Besides tools, the printer comes with a full spool of Galaxy Black Prusament PLA, a USB Stick, a handbook on 3D printing with your new machine, and a bag of Gummy Bears. The USB stick contains several models, while PrusaSlicer is available for free download from the website.

We also received a Buddy Camera and several boxes of filament to perform the review.

Design of the Prusa CORE One+ INDX

The CORE One+ INDX is a Core XY 3D printer converted into a toolchanger. It has a slim, steel exoskeleton with indents on either side. The right side holds a 3D-printed waste container on the outside for the tiny bits of filament the machine drops from the wiper system inside the chamber. We’re unsure if this mod is a permanent feature or an apology bonus for being unable to deliver fully hardened steel nozzles at launch.

Like the original CORE One, the door and upper parts of the side panels are translucent black polymer. The top panel is now replaced by a “top hat” to give the multitude of Bowden tubes room to work. Since the shell is made of folded steel, it’s not exactly airtight, but so far we haven’t had any trouble printing ASA or ABS in the machine.

The exoskeleton is an interesting concept. It provides a strong, stiff frame for the printer while also minimizing materials and avoiding that cheap plastic feel that plagues many other designs. The indented sides do more than slim down the printer’s silhouette; they reduce the interior space of the printer, allowing the chamber to be sufficiently heated (when needed) by only the heater bed.

Like every other Prusa printer before it, several of the CORE One+ parts are 3D printed with PC Blend Carbon Fiber, though more pieces are moving to in-house injection molding. Most of the machine is manufactured at the main factory in Prague, though printers assembled in the United States will have some parts printed locally in Delaware.

The CORE One+ has a door that can be flipped to open on either side. And thankfully, that door can remain closed at all times thanks to an active cooling system and automatic top vent.

The INDX ditches the Nextruder extruder for the Bondtech induction-heated toolhead. The toolhead looks way too exposed out of necessity, as it picks up the passive nozzles by simply ramming itself onto the rack and grabbing the toolhead with magnets. The motion system is extremely accurate, and I had no problems with it during testing. You can see the copper coils of the induction heating system very plainly.

Unlike the Prusa XL, the toolheads mount on a rack in the front of the chamber. They take up very little space, but you will lose 15 mm of Y and 2 mm of X on the build plate compared to the CORE One+.

The rack does make seeing inside the printer a bit of a challenge, but the optional Buddy Cam has a clear view from the inside.

The wiper is located to the side, on top of the indent. In the Founder’s Edition, the wiper dumped into a small removable cup clamped to the side panel. Our review unit has a hole drilled into it to dump into a large exterior container, which is a huge improvement.

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Anyone who’s had to calibrate an XL will rejoice at the new automatic tool offset calibration system. A calibration sensor sits in the front corner of the machine, and you don’t need to do a thing but keep it clean.

The CORE One+ has active chamber temperature control, which is NOT the same as chamber heating. Instead, the machine’s interior geometry is optimized to capture heat thrown from the bed to heat the chamber up to 55C. A fan and smart ventilation system likewise keep the chamber cool enough for PLA even with the door closed.

Assembling the Prusa CORE One+ INDX

The Prusa CORE One+ INDX we reviewed came fully assembled and only needed to be unpacked. Simply pull it out of the box, remove the packing materials, snap the screen on and the spool holders, and plug it in.

Once the machine is turned on, you’ll see a cartoon version of Josef Prusa to guide you through setup. However, calibration is now handled at the factory, so there’s nothing left to do but make sure you’ve removed the zip ties and carry on your merry way.

Leveling the Prusa CORE One+ INDX

Bed leveling is a no-brainer, as the Prusa CORE One+ is fully automatic. There are no manual adjustments and no need to adjust the Z offset. The printer uses a load cell sensor connected to the nozzle, which physically taps the print surface for precise measurement.

The printer trams the bed and calculates the required Z height before each print. And yes, if you need it, live Z adjustments are available in the control panel.

Loading Filament on the Prusa CORE One+ INDX

Loading filament is very simple. Simply place the spools on the side-mounted rack and feed the plastic into the reverse Bowden tube until it reaches the hotend. You’ll need to open the printer menu and tell it which toolhead you’re loading, since the toolheads themselves are passive. The carriage will zip over, grab the requested tool, and take it to the nozzle wiper to purge a small amount of filament into the cup. It will wipe the nozzle and park the toolhead when you’re done.

The inductive heater brings each nozzle up to temperature in a matter of seconds.

Unfortunately, the printer only asks what kind of filament you’re loading (PLA, ASA, Flex, or more) but not what color. This is probably due to the fact that the slicer does not constantly communicate with the printer over the cloud, but I’m hoping that this feature will become available with a future firmware update. For now, you’ll have to manually enter your filament colors into the slicer. There is a remapping option on the control screen, but shifting around eight spools' worth of information in this fashion is tedious.

The spoolholders are sturdy manual devices that can hold literally any brand of filament you might be using. They even expand to hold 3KG spools.

Preparing Files / Software for Prusa CORE One+

The Prusa CORE One+ uses its native slicer, PrusaSlicer. This open-source slicer is developed by Prusa Research and serves as the foundation for many other slicers. It comes with dozens of profiles for every material and nozzle size that Prusa Research makes.

The slicer also has built- in Color Mixing, which allows you to blend two or three colors with ultra-fine layers to create the illusion of more colors.

The CORE One+ can also use Prusa’s web-based slicer, EasyPrint, to print directly from Printables, Prusa’s free library of files, or from a mobile device.

Printing on the Prusa CORE One+ INDX

The fully assembled CORE One+ comes with a full 1 KG roll of Prusament PLA Galaxy Black. If you want more colors and materials like silks and multicolor filaments, you should check out our guide to the best filaments for 3D printing for suggestions.

I used some of the sample rolls sent my way, plus a couple more lying about the workshop, to Prusa’s new calibration butterfly, Otto. This eight-color sample test print took 1 hour and 14 minutes. The wings are a first-layer test and are only two layers thick. A tab on the wing slots into the body to prove that tolerances and extrusion flow are correct. The multi-colored wing segments act as a visual test for first-layer quality, belt tension, and toolhead alignment, as any tiny offset in color boundaries or axis motion will show up instantly. This is a lot more useful than a Benchy for multicolor printing, and it makes a cool decoration you can keep on the shelf.

I printed this 100%, 150mm tall, Cinderwing3D Butterfly Dragon that I could never get to stick to the bed with other multicolor machines. Sitting next to it is a small container with all the waste this print produced from 1646 tool changes: 18 grams. When you look really close, they look like Nerds candy.

This printed in 25 hours, 41 minutes, using a .2 mm layer height, 3 walls and 10% gyroid infill. It took a little longer to print because I slowed it down to 100mm/s across the board due to the precarious wing situation. The filament is Prusament PLA in Orange, Yellow, Simply Green and Galaxy Black; Inland Purple, and Bambu Lab Basic Pink.

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For PETG, I printed a planter I designed. I’ve been trying to learn Nomad Sculpt, but I still need to rough things out in Tinkercad. For that reason, please excuse the rough layer line near the bottom, which is entirely a design flaw and not the printer’s fault. PETG doesn't color swap quite as cleanly as PLA, and I had to pick a few stray flecks off the print. Otherwise, it’s pretty darn good. This is printed in Prusament Galaxy Black and Yellow Gold PETG, with Deepwater Blue from Greengate. This print took 6 hours and 14 minutes to print using default settings and a .2mm layer height. There was 6.84 grams of filament wasted with 537 tool changes.

For high-temperature testing, I made these pumpkin containers, again with a mash-up of Tinkercad and my fledgling Nomad Sculpt skills. You really don’t want to see the insides of these things. But they printed really well in Prusament ASA Orange and Galaxy Black, with Ambrosia Armored Turtle Green ASA. I couldn’t find any white ASA, so I found a random spool of white ABS to fill in. The printer had no problem mixing the two materials as they are quite similar. I don’t think this photo does the orange justice; it’s possible it’s a bit fluorescent. Most importantly, there was no odor while these ran, as the printer remained closed and filtered. The large pumpkin took 13 hours and 45 minutes to print using a default .2mm layer height. It had 9.4 grams of waste over 632 tool changes.

A note on TPU: The Prusa INDX does not have an official profile for flexible materials as yet, but it is listed as being TPU-capable. I wrote up my own profile, copied from a standard CORE One+, and had mixed luck. It had difficulty with oozing and would occasionally jam up when trying to print with more than one color. This needs further work and experimentation.

Bottom Line

The Prusa CORE One+ INDX is the machine Prusa Research needs right now to compete in the modern marketplace. Is it a bit of a splurge? Yes, but the company’s reputation for reliability, right to repair, data security, and continued support through the years makes it a safe splurge.

Starting at $749 for a four-tool conversion kit and going to $2,119 for a fully assembled machine with the works, the CORE One+ INDX offers flexible price points for Prusa fans. Once assembled, the 3D printer itself is easy enough for families and school kids to use, but capable enough for small businesses and workshops. Plus, the ability to take the machine completely offline means it's a secure work partner for those who are mindful of data security or simply have unreliable internet service.

If you're a tinkerer and already have a CORE One or heck, even a MK4S, there is an upgrade path that could be a fun project that will net you the latest printer at half the cost.

If a Prusa machine seems just a bit too spendy for your budget, the $849 Snapmaker U1 is an awesome four-color toolchanger with an evolving ecosystem and a thriving community of users. The Bambu Lab H2C nozzle swapper is a touch more expensive at $2,499, but has a larger 330 x 320 mm build plate, even if it only does five colors.

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