Chinese 3D printer manufacturer Bambu Lab sent a cease-and-desist letter to Polish developer Paweł Jarczak, forcing him to remove a fork of OrcaSlicer that restored cloud printing features the company had locked to its own software.

Within days, YouTubers with audiences in the millions had pledged $20,000 in legal defense funds, rehosted the code, and announced they were switching to rival hardware. The dispute began as a narrow technical argument but has since drawn in a non-profit legal organisation with a track record of suing hardware manufacturers over open-source licence violations.

Jarczak’s public response, posted after Bambu Lab refused to share the full correspondence. Image via Paweł Jarczak/GitHub.

The Roots of an Open-Source Clash

Bambu Lab’s own slicer, Bambu Studio, is a fork of PrusaSlicer, which is itself a fork of Slic3r. All three are distributed under the AGPLv3 license, which requires derivative works to also be released as open source. Jarczak’s project, OrcaSlicer-bambulab, let users route print jobs through Bambu’s cloud without the company’s proprietary Bambu Connect middleware, introduced after purchase to restrict third-party software access.

In a blog post, Bambu Lab argued that the fork used a hardcoded version number to present itself as official Bambu Studio traffic, making it indistinguishable at the server level, and cited documented outages from unauthorized traffic spikes as evidence of real infrastructure risk. 

Its stated position: “a license for code is not a pass to our cloud infrastructure.” Jarczak disputed every charge, noting that the method his fork used came directly from Bambu’s own published AGPLv3 source code, unmodified.

A company running remote monitoring across a large installed base has a legitimate interest in controlling server traffic. The problem, as open-source developer Jeff Geerling explained, is that Bambu applied that argument not through policy or technical controls but through legal threats directed at one developer working with the company’s own published code.

YouTuber Louis Rossmann reposted the code on GitHub on May 12 with Jarczak’s permission after offering him $10,000 in legal support, which Jarczak declined. Gamers Nexus matched the pledge, rehosted the files independently, and announced it was switching to Prusa hardware. Rossmann’s FULU Foundation formally republished the fork by May 14.

The conflict is not unique to 3D printing. Cybernews quoted lawyer and YouTuber Leonard French framing it as a case of “what right-to-repair advocates have started calling progressive enclosure,” a strategy used by manufacturers to convert one-time hardware sales into ongoing managed services through software locks.

Project Baltobu Mounts a Legal Offensive

On May 18th, the Software Freedom Conservancy (SFC) announced it had confirmed two separate AGPLv3 violations by Bambu Lab. The first predates Jarczak entirely. Bambu has distributed a proprietary networking library, libbambu_networking, alongside Bambu Studio for years without releasing its source code, which SFC says breaches the licence’s requirement to provide a complete corresponding source. 

The second violation, in SFC’s assessment, is the legal threat against Jarczak itself, which it argues contravenes AGPLv3’s prohibition on imposing further restrictions on rights the licence grants.

SFC has launched a project called baltobu to reverse-engineer the networking library, maintain Jarczak’s OrcaSlicer fork, and develop a replacement fork of Bambu Studio. Jarczak has joined as a collaborator. SFC has opened a $250,007 fundraiser to fund long-term staff on the effort, with over $60,000 raised at time of publication.

SFC’s fundraiser tracker showing $61,222 raised toward a $250,007 target for its Bambu Lab compliance effort. Image via SFC.

Rossmann’s earlier contention, that Bambu cannot coherently invoke legal protection for code it published under a licence designed to prevent exactly that restriction, now has institutional backing. 

Whether the dispute resolves through compliance, litigation, or a reverse-engineered replacement for Bambu’s proprietary library, it has moved beyond a community backlash into organised legal scrutiny that Bambu Lab will need to formally answer.

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Featured image shows SFC’s fundraiser tracker showing $61,222 raised toward a $250,007 target for its Bambu Lab compliance effort. Image via SFC.