Last checked: August 17, 2026.
Status check: the Bondtech INDX — the 8-material toolchanger add-on for Prusa’s CORE One — is real, hands-on reports confirm the mechanism delivers, and you still can’t easily get one. The 1,000-unit Founders Edition shipped in July. The first batch of standard conversion kits sold out back in April and hasn’t left the factory yet. Per Prusa’s August 13 update, compensation news comes “early next week” and shipping “very soon after that.” The delay has one root cause, and the community has a name for it: Nozzlegate. Bondtech shipped nozzles that aren’t the hardened steel its marketing promised. Here’s where everything stands, what the nozzle issue means in practice, and whether ordering now makes sense.
Where INDX stands right now
- November 2025: Bondtech and Prusa announce INDX, an 8-material toolchanger built for the CORE One.
- April 23, 2026: Conversion kit orders open; the first batch sells out within days — “in record time,” in Prusa’s words. US pricing has been listed at $749 for the 4-tool kit and $999 for the 8-tool kit, tariffs included; Prusa’s Czech store sells the 4-tool kit at 15,990 CZK. Each kit bundles the Smart Head, passive tools with 0.4 mm nozzles, spool holders, and the docking hardware.
- Early July 2026: The limited Founders Edition (1,000 units, sold through Bondtech) ships. Prusa’s July 3 update calls it “out in the wild”; Tom’s Hardware got one and assembled the 8-tool kit for a hands-on report by mid-July.
- July 17-18, 2026: Reddit and Discord users discover the shipped nozzles aren’t through-hardened. Product pages quietly drop the word “hardened.”
- July 29, 2026: Bondtech formally confirms the substitution.
- July 31, 2026: Prusa postpones standard kit shipping to mid-August and commits to “ship every conversion kit we can,” warning that nozzle production is the bottleneck.
- August 13, 2026: Mid-August slips too. Compensation details are due the week of August 17, shipping “very soon after.”
Bondtech’s own store sells the INDX Smart Toolhead separately at $390 with passive tools at $40 each — a developer-oriented line with shipping starting late August into September. The CORE One kits themselves are sold through Prusa.
Nozzlegate: what actually happened
Prusa’s April announcement promised the kits would ship with “hardened high-flow 0.4 mm nozzles.” Bondtech’s marketing went further, promising “zero fear of wear” with carbon fiber, glass fiber, and glow-in-the-dark filaments. What shipped instead: nozzles with a nitrocarburized surface treatment measuring roughly 30-32 HRC. That’s a real surface-hardening process, but it isn’t the through-hardened steel at around 60 HRC that the marketing language implied. For scale, ordinary untreated steel sits at 20-25 HRC.
Bondtech’s explanation — given to founders in mid-July support emails and repeated publicly — is that mass-producing truly hardened nozzles kept destroying the production tooling: “The cutting tools simply did not withstand the process.” Rather than delay, Bondtech shipped the softer version, and the marketing language never caught up. The community caught it first, through a support email and hardness tests shared on Reddit and Discord around July 17-18. The formal statement followed on July 29.
What does it mean in practice? For standard, unfilled filaments — PLA, PETG, ABS — nozzle hardness matters little. The promise that broke is abrasives: CF- and GF-filled spools of any polymer, plus glow-in-the-dark blends, are exactly what wears soft nozzles down, and exactly what the marketing sold. Genuinely hardened replacements are “many months” away by Bondtech’s own account. A Bondtech representative promised that “all founders will be compensated,” but as of mid-August the concrete plan is still pending; refunds and discounts on future hardened nozzles have been floated, and details are due this week.
One separate early-unit note: the community troubleshooting list also documents nozzles blocked from the factory by machining debris. If a brand-new tool refuses to extrude and the extruder clicks, that’s the first thing to check.
How INDX works, and why the waste numbers matter
Single-nozzle filament switchers like Bambu’s AMS or Prusa’s own MMU3 share one nozzle among all filaments, which means purging: melting away the old color until the new one runs clean. INDX takes the toolchanger route in a retrofit format — each material gets its own complete nozzle assembly parked in a rack at the back of the printer, and the toolhead swaps assemblies instead of flushing a shared melt zone. There’s still a little tool-change waste; Bondtech puts it at about 13 mg per change. Prusa markets that as one-fifth the waste of the most efficient competing systems and as little as one-thirtieth of filament-rewinding systems. A complete tool change, nozzle heat-up included, takes about 12-16 seconds.
INDX caps out at 8 materials, and only on a Prusa CORE One or CORE One+. Bambu Lab attacks the same purge problem with its Vortek hotend-swap system — built into the H2C printer ($2,399) and sold as an upgrade kit for H2D/H2S owners. We compare that machine in detail in our H2C vs H2D guide.
INDX vs AMS 2 Pro vs MMU3
One caveat before the numbers: this isn’t an apples-to-apples trio. INDX is a toolchanger retrofit; AMS 2 Pro and MMU3 are filament switchers feeding a single nozzle. They solve the same problem for very different money.
| Bondtech INDX | Bambu AMS 2 Pro | Prusa MMU3 | |
|---|---|---|---|
| Mechanism | Dedicated nozzle per material, toolhead swaps them | Spool switcher, single shared nozzle | Spool switcher, single shared nozzle |
| Materials | Up to 8 | 4 per unit, chainable to 16 | 5 |
| Purge waste | ~13 mg per change (Bondtech’s figure) | Purges on every change — less than the first-gen AMS, but never zero | Purges; Prusa claims 73% less waste than competitors on PLA/PETG defaults |
| Change speed | ~12-16 s incl. heat-up | Feed motor 60% faster than gen 1; total varies with purge | 35-45 s (typically ~42 s since the March 2026 firmware update) |
| Printers | CORE One/+ only | Most current Bambu printers | MK4S, MK3.9S, CORE One (enclosed variant) |
| Price (US listings) | $749 (4-tool) / $999 (8-tool) | $299 | $399 assembled |
| Availability | Backordered; first standard batch not yet shipped | In stock | In stock |
CORE One L: not yet, despite the banner
Prusa’s CORE One L+ product page carries the headline “GET CORE ONE L+ NOW, UPGRADE TO INDX LATER,” and that second half is doing a lot of work. The 8-tool kit page lists the CORE One L as not compatible today. Conversion kits for the L, along with factory-assembled printers with INDX preinstalled, are “planned to become available later this year” (Prusa, April 2026) — and as recently as August 12, a Prusa staffer answered a pricing question with “sadly nothing yet.”
Two details worth knowing if you’re holding out for the L version. Prusa staff have said the L’s rack has physical room for 10 tools instead of 8 — though physical space is not a firmware or product promise, so treat 8 as the real number until Prusa says otherwise. And the August 12 lineup refresh (CORE One+ Gen 2, CORE One L+ Gen 2, XL+) kept prices unchanged. Buying an L+ today buys you a promise, not a capability.
Should you order now?
You own a CORE One/+ and print multi-color heavily: order, and treat the queue as part of the price. At ~13 mg per change, the waste savings are structural, not incremental. Just keep abrasive filaments away from the current nozzles until through-hardened ones actually exist — and if you’re in batch one, watch this week’s compensation announcement before spending more.
You want carbon-fiber multi-material today: wait for the hardened nozzles, or look at the Vortek route on the H2C. The current INDX nozzles are the wrong tool for the job the marketing promised.
You own a CORE One L: there’s nothing to buy yet. “Later this year” is the only official timeline.
You don’t own a compatible printer: the CORE One is the ticket in, and it’s a strong printer even before INDX enters the picture. Check the current CORE One price, or line it up against 23 printers in our printer comparison tool.
FAQ
Is INDX shipping right now? The Founders Edition shipped in July 2026. Standard conversion kits hadn’t shipped as of August 17; Prusa’s latest update puts compensation news first, with shipping “very soon after.”
Does INDX work with the CORE One L? Not yet. Only the CORE One and CORE One+ are supported. L kits and preassembled INDX printers are promised for later in 2026.
How much waste does INDX actually save? Bondtech puts tool-change waste at about 13 mg. Prusa markets that as one-fifth the waste of the most efficient competitors and as little as one-thirtieth of filament-rewinding systems.
How fast is a tool change? Around 12-16 seconds including nozzle heat-up. Bondtech’s official figure is ~14 seconds.
What is Nozzlegate in one sentence? INDX shipped with surface-treated nozzles at roughly 30-32 HRC instead of the promised through-hardened ~60 HRC steel, which makes them a poor match for the abrasive filaments the marketing explicitly advertised — and compensation details are still being worked out.
