Prusa INDX Kit Delayed After Bondtech Nozzle Defect Surfaces

Prusa Research has halted shipments of its INDX toolchanger conversion kits for the CORE One after a manufacturing defect came to light. Bondtech, the Swedish company that designed the INDX system, confirmed that the nozzles included with Founders Edition kits are nitrocarburized steel, not the fully hardened steel promised in marketing materials.

The delay will push INDX kit deliveries to mid-August at the earliest. Prusa emailed all customers with active INDX orders on August 2, explaining that the company wants clearer answers before sending out more hardware.

What went wrong

Bondtech founder Martin Bondeus revealed the issue in a support email that surfaced on Reddit. He wrote that production challenges prevented the company from machining the originally specified hardened steel reliably. The cutting tools simply could not withstand the process. Instead of releasing inconsistent parts, Bondtech chose to ship nitrocarburized nozzles as a temporary measure.

That decision backfired. The nitrocarburized nozzles measure around 30-32 on the Rockwell C scale. True hardened steel typically sits at 55-60 HRC. For everyday PLA, PETG, and TPU, the difference means little. The nozzles will outlast standard brass by a wide margin. But once abrasive filaments enter the mix, the treated steel wears faster than expected. Bondtech batch-tested the nozzles with carbon-fiber PETG and saw minimal wear after five kilograms. Switch to Ultraglow glow-in-the-dark filament, and the protective coating began failing after just 100 grams.

Customer fallout

Founders Edition buyers paid a premium for early access. Many have already taken apart their CORE One printers to install the INDX system, a process that can consume an entire weekend. Prusa is now offering extra hardware free of charge with delayed kits, but has not specified what that hardware will be.

One frustrated customer went further. He built an entire protest website called Nozzlegate.com, laying out grievances against Bondtech and advising buyers on their options. The situation has generated heated discussion across Prusa and 3D printing communities.

The path forward

Bondtech says a "concrete solution" is not ready. Manufacturing truly hardened INDX nozzles could take months. The company is not offering compensation yet, because it does not know the replacement cost. It is asking customers to hold off on returns and avoid abrasive materials for now.

Prusa Research still stands behind the INDX concept. The system itself works well when paired with appropriate filaments. The misstep is in the communication, not necessarily the product. A clearer disclosure from the start, before pre-orders locked in, would have avoided much of the anger.

For buyers waiting on INDX kits, the message is simple: the upgrade will arrive, and it will include something extra as an apology. If you planned to run carbon-fiber or glow-in-the-dark filament through your INDX, you may want to hold off until hardened nozzles are confirmed.