Prusa's INDX Toolchanger Adds 8 Colors to the CORE One Plus

Prusa Research and Bondtech have started shipping the retail version of the INDX toolchanger, an add-on that turns the Prusa CORE One Plus into a multi-material machine with up to eight independently heated tools. First revealed at Formnext 2025 and previewed to early backers through a limited Founder's Edition run, the system is now available as a conversion kit with prices starting at $749 for a four-tool configuration and $999 for the full eight-tool setup.

How it actually works

Unlike conventional multi-material systems that push several filaments through one hotend, INDX keeps each tool completely separate. Eight tools mount across the front of the printer. When the slicer calls for a different material, the printhead parks the active tool, moves to the next one, and that tool's nozzle is brought to temperature in a few seconds using induction heating. The machine then resumes printing without a long transition delay.

Waste is the clearest win. Purge towers on standard multi-material systems can burn through hundreds of grams of plastic on a complex color print. Prusa says INDX produces roughly 0.013 to 0.015 grams of material per tool change, routed into a small silicone-cleaned waste bin rather than a tower. On the multi-color rocket engine demo print Prusa showed at launch, the INDX produced under 30 grams of waste compared with more than 800 grams on a conventional setup.

What early users are actually seeing

The YouTube review channel Canuck Creator posted a full livestream setup walkthrough on August 22 and confirmed the swap speed claim in real use. Tool changes happened fast enough to make multi-material prints practical without halting for minutes at a time. The system also won praise for keeping nozzles clean: an eddy current sensor on the bed corner performs automatic offset calibration and nozzle cleanliness checks before every print, removing one of the main failure points on earlier toolchanger designs.

Those positives come with real caveats. Installation of the conversion kit is not a quick afternoon project. Prusa puts the labor time at seven to 12 hours, and the company is still considering whether to offer fully pre-assembled CORE One Plus INDX units to avoid the assembly barrier. The Founders Edition units that went out in July were explicitly described as unfinished. Prusa asked reviewers not to treat them as final products, and at least one prominent reviewer confirmed he will revisit the system once retail profiles and assembly improvements are in place.

The nozzle controversy

The biggest stain on the launch so far is what fans are calling "Nozzlegate." Initial batches of the INDX upgrade kit shipped with nozzles Bondtech described as hardened steel. Testing by owners found the nozzles measured around 30 to 32 on the Rockwell C scale. True hardened steel nozzles sit at 55 to 60 HRC. Bondtech later clarified that the nozzles were nitrocarburized, a surface treatment that produces a shallow hardened shell rather than through-hardening, and that the testing method used was not appropriate for that kind of case depth.

The admission did not satisfy all owners. Bondtech's public statement acknowledged that a properly hardened replacement nozzle was months away and offered no immediate compensation, asking customers to stick with non-abrasive materials in the meantime. Customer law in several European countries gives buyers a two-month window from the disclosure date to request a refund, and discussion threads suggest some owners are pursuing that route.

Prusa Research has not directly apologized for the nozzle issue but did publish a blog post and a firmware update around the same time. Firmware 6.6.1 and 6.6.2 added a larger waste bin, improved cleaner positioning, and better offset persistence. Whether those updates address the core complaint depends on whether you need hardened nozzles for carbon-fiber or abrasive-filler materials today, or if you are happy to wait.

Who should buy now

The INDX is genuinely interesting if your work regularly requires more than two or three material changes per print. The waste savings alone justify the expense for small production runs, and the speed of the tool swaps puts it ahead of single-hotend systems like Bambu Lab's AMS or Prusa's own older multi-material approach on complex files.

If you mostly print single-color models, the math changes fast. Eight loaded spools tie up filament, moisture, and capital. The kit is only compatible with the CORE One and CORE One Plus, leaving owners of the CORE One L or earlier Prusa machines out. Assembly time, still-evolving software profiles, and the nozzle hardness question all point to this being a product best bought by people who actively need the capability today and can tolerate early-product friction.

For everyone else, waiting for a fully assembled retail unit plus hardened nozzle availability probably makes more sense. Prusa has a track record of fixing these problems, but the track record does not help you if you unbox a $999 kit and cannot print the material you bought it for.