By ByteBot
3D printer manufacturer Bambu Lab sent a cease-and-desist letter last week to independent developer Paweł Jarczak for creating OrcaSlicer-BambuLab, a fork that restored cloud printing functionality Bambu had removed in January 2025. The fork used AGPL-licensed code—a copyleft license that explicitly permits derivative works—but Bambu claimed Terms of Service violations anyway. Jarczak shut down the project under legal pressure. Within hours, the story hit #1 on Hacker News with 848 points, and Louis Rossmann, prominent right-to-repair advocate, pledged $10,000 toward legal defense.
This isn’t about security. It’s about control. Bambu Lab is testing whether hardware manufacturers can use Terms of Service to override open source license protections, and the answer matters far beyond 3D printing.
AGPL Exists for Exactly This Use Case
The GNU Affero General Public License v3 explicitly permits creating derivative works and forks. It’s not ambiguous. The entire software chain—Slic3r → Prusa Slicer → Bambu Studio → OrcaSlicer → OrcaSlicer-BambuLab—is AGPL-licensed. Jarczak used Bambu Studio’s upstream code verbatim, precisely as copyleft licenses are designed to allow.
Bambu Lab itself built Bambu Studio as a fork of Prusa Slicer. They benefit from AGPL code every day. Furthermore, Jarczak previously contributed to Bambu’s own GitHub projects, establishing good faith. This wasn’t reverse engineering or code theft—it was standard open source development using permissions the license grants.
The copyleft principle is simple: if you use copyleft code, your derived work must be open too. Fork rights are explicitly protected. Developers can modify and redistribute under the same license. That’s the deal. However, if Terms of Service can override AGPL protections, copyleft licenses become meaningless. Hardware manufacturers could ban forks, restrict modifications, and lock down ecosystems—all while benefiting from open source code themselves.
When Roles Were Reversed, Prusa Showed Restraint
In 2022, Bambu Studio accidentally routed telemetry data to Prusa’s servers, overwhelming their infrastructure with unauthorized traffic. Prusa Research didn’t send a cease-and-desist letter. They fixed the issue quietly and maintained community goodwill.
Four years later, when the situation reversed, Bambu Lab chose legal threats instead of collaboration. Jeff Geerling, Red Hat engineer and prominent tech blogger, captured the hypocrisy: “You can’t have it both ways—benefit from open source when it suits you, then threaten legal action when others exercise the same freedoms.”
This is the worst kind of corporate behavior. Bambu Lab built its success on open source generosity—Prusa’s forbearance in 2022, community support that made OrcaSlicer the most popular slicer for Bambu printers. Now they’ve abandoned those same principles because it serves their business interests.
Bambu Connect: Security Theater or Lock-In?
In January 2025, Bambu Lab removed OrcaSlicer’s direct cloud printing access. They forced all connections through Bambu Connect, proprietary middleware that severely limits third-party slicer functionality. Users can no longer send print jobs directly to printers they own. Bambu claimed this was for security and to prevent 30 million daily “unauthorized” requests.
The 3D printing community sees it differently: ecosystem control disguised as infrastructure protection. For decades, 3D printers worked with any slicer—Cura, PrusaSlicer, Simplify3D, OrcaSlicer. Software independence was assumed. Consequently, Bambu’s restriction breaks that standard.
Security is a valid concern, but forcing ALL traffic through proprietary middleware isn’t the only solution. Better infrastructure, rate limiting, and API keys could address “unauthorized” requests without killing software freedom. Bambu chose the most restrictive approach—the one that gives them maximum control, not maximum security. When a developer restored direct access using AGPL code, Bambu sent lawyers instead of improving their architecture.
Louis Rossmann Puts $10,000 on the Table
Louis Rossmann, right-to-repair advocate with 2.35 million YouTube subscribers, pledged $10,000 toward Jarczak’s legal defense. His argument is simple: “If you bought it, you own it.” Owners should have the freedom to fix, modify, and maintain products. Therefore, forcing middleware is ecosystem lock-in that violates ownership rights.
“If Bambu Labs goes after you for keeping up your code, I am so confident in your case that I will pay the first $10,000,” Rossmann said in a video mobilizing the right-to-repair community for crowdfunding. This is a test case for whether hardware manufacturers can restrict software freedom through Terms of Service, even when open source licenses explicitly permit the modifications.
Rossmann’s involvement elevates this from niche 3D printing controversy to broader right-to-repair movement. His $10,000 pledge signals confidence that Bambu Lab’s legal position is weak. Moreover, if Jarczak fights with community funding, this could establish legal precedent protecting open source hardware modifications against ToS restrictions.
Community Backlash Threatens Bambu’s Foundation
The Hacker News thread hit 848 points with 295 comments, overwhelmingly supporting the developer. Comments captured the sentiment: “AGPL exists for exactly this use case,” “Bambu benefited from Prusa’s open source generosity, now pulls the ladder up,” “Corporate overreach disguised as security concerns.” Additionally, many developers vowed to avoid Bambu Lab printers.
Geerling published a scathing analysis recommending customers “consider alternative manufacturers” who respect open source principles. He argued Bambu misunderstands open source culture: companies that fight communities built on openness rarely win.
Bambu Lab’s success was built on that community—early adopters, OrcaSlicer developers, open source enthusiasts who championed their printers despite higher prices than established brands. Alienating that community threatens their market position. In contrast, Prusa Research gains goodwill. The 2022 incident showed how open source communities prefer collaboration over litigation.
Verdict: Bambu Lab Is Wrong
This is corporate overreach, not security enforcement. AGPL licenses exist to prevent exactly this scenario—companies benefiting from open source code, then restricting the freedoms that made that code possible. If Terms of Service can override copyleft protections, open source hardware development faces a chilling effect. Why contribute to projects if manufacturers can later ban your modifications with legal threats?
The precedent matters beyond 3D printing. Apple walled gardens and gaming console restrictions work because users accept the trade-off: curation and integration for lock-in. Bambu Lab marketed as open-source-friendly, benefited from community support, then imposed restrictions post-purchase. That’s bait-and-switch, and communities remember.
Jarczak should fight with Rossmann’s support. Bambu Lab should withdraw the cease-and-desist and fix their infrastructure instead of restricting software. Customers should demand open-source respect or consider Prusa and other alternatives. Open source licenses must mean something, or they mean nothing.
