Is “INDX” the ultimate Prusa 3D CORE One multi-material printer upgrade? We don’t get to find out, yet.

CORE One with BondTech ‘INDX’ (image provide by BondTech)

Prusa has long been a leader in upgradeable 3D printers — don’t throw the old one away, buy an upgrade! Thus you could at various times update a MK2 (“Mark Two”) to MK3, MK3 to MK3.5, MK3.5+ to MK4, MK4 to MK4S, and most dramatically, completely rebuild your MK4S into a CORE One core xy printer. All at significantly less than the cost of the new printer. For example, if you have the CORE One, the website currently states:

Current CORE One owners can easily upgrade to the new CORE One+!
You can either download the free print-it-yourself files from Printables
or purchase the official upgrade kit from our e-shop.

That upgrade kit, by the way, sells for just US$15 plus shipping. Most upgrades are not so inexpensive, of course.

More importantly, Prusa just announced — ​in conjunction with Swedish printhead/extruder experts BondTech — yet another upgrade for the CORE One, the INDX; see the Prusa Announcement and the BondTech page. BondTech’s prices as of November 2025 do not cover the complete Prusa kit, which is expected to retail for US$499 (4 heads) or US$699 (8 heads). The INDX sounds spifftastic on the web sites — it adds 4 or 8 colors and each has a ($35!) mini-print-head resulting in basically zero wasted filament when switching colors. It’s not cheap, of course. The Prusa announcement says that the early-adopter “Stage 1” will become available in Q1 2026, but this discounted “Founder’s Edition” was sold out in an hour or so on Feb 18 (cue massive web-site overload music), and I missed the chance to get in :-( Prusa’s current multi-color attachment, the MMU3, has up to 5 colors and half the price of the INDX but is kinda Rube Goldberg.

All that aside, I have to wonder if Prusa is losing ground. They are pursued by many Asian makers: Bambu, SnapMaker, Creality, Sovol, and more. To take one example, SnapMaker’s U1 lists at $999, is on sale this week and several times a year for $849, offers 4 colors max, but has 4 or 5 second filament swap time. The INDX swap time claims range from 8 to 12 seconds. That’s each time you swap filaments. A decent print may have hundreds or even thousands of print swaps. Adding up the difference between 12 seconds and 5, spread over a thousand swaps, is 7000 seconds, or 7000/60 or about 115 minutes extra printing time (I have of course invited Prusa to respond to this comparison but have not heard back after several days). That CORE One + 4-color INDX (bought separately, at today’s listed prices) would cost US$1,319 + US$499, or US$1818. Not bad next to the newly-minted Bambu Lab H2C which starts at €2,399. You could shave a bit off the CORE One by assembling it from a kit at US$1009. Or, you could buy two of the Snapmakers and have some redundancy. Why, then, go with the Prusa?

Why Prusa?

Prusa has (like any other tech) curated a loyal (occasionally rabid) fan base. They (and I, hopefully not rabidly) will tell you that Prusa’s advantages are worth the extra cost:

• Company founder Josef Prusa practically invented consumer-priced 3D printing (based on his work with the earlier RepRap project).
• Ethical: Prusas are designed and manufactured in Europe, where workers are paid a decent wage.
• Continual upgrades: free firmware updates for life, and always a hardware upgrade path.
• Almost everything is open source, including the hardware.
• Prusa provides a complete ecosystem:
• • They maintain the open-source PrusaSlicer (a fork of Slic3r), which includes profiles for competitors’ printers and filaments.
• • They make their own filament, Prusament
• • They sponsor Printables.com, one of the largest 3d printing model download sites with contests, store credits for uploads and downloads, and more.
• • Flexible inputs: USB stick, WiFi, wired Ethernet, with both localnet web and cloud-based control (including a mobile app for the latter).
• • Some people like to modify hardware, and the systems are largely modder-friendly.
• • Reputation for reliability: uptime really matters in commercial printing!
• • Security: all versions can be operated completely offline; the CORE One L (large) has two WiFi-free options; just remove one screw and unplug the WiFi card, or, order the special version whose mainboard doesn’t even have the connections for the WiFi card (this is both important for security-paranoid organizations, and ironic, since the earliest consumer 3D printers didn’t even have networking).
• Also there are huge communities of helpful users.

So all considerations weighed, I shall be keeping my CORE One and plan eventually to get the INDX upgrade, though I’ll have to let others be the “early adopters” (remembering the line about how “you can tell the pioneers…”).

P.S. I’m now accepting offers for my MMU3 kit, which I never got round to assembling [Update: it sold].

P.P.S. INDX? INdependent, Dynamic eXtrusion.

Update 2026–04–24: Prusa announced with great fanfare that they were opening orders for the INDX Upgrade kit, priced at US$749/CAD$1059. You could, in fact, order one. A day or so later, they were closed again; the order page again says “Notify me when available” (viewed 2024–04–26). Because they sold all the units they had. More will become available in batches. So someday we’ll have one in hand, probably, maybe.