Stratasys v. Bambu Lab — Judge Gilstrap Issues 23 Pretrial Rulings, 3D-Printing Patents Advance to Trial with § 101 Wins and a Damages Hit

Background

Stratasys — the company widely credited with inventing fused deposition modeling (FDM) 3D printing — has been in a multi-front patent war with Bambu Lab, a fast-growing Chinese 3D printer maker whose machines have taken significant market share from Stratasys’s consumer and prosumer lines. The district court case involves at least eight asserted patents covering FDM build-path algorithms, tagged filament spools that auto-configure printers, heated build platforms, networked print management, and multi-material purge towers.

On July 2, 2026, Judge Gilstrap issued a comprehensive pretrial conference order memorializing rulings from a May 7–8, 2026 hearing that addressed 23 categories of pending motions: summary judgment on validity and infringement, Daubert motions to exclude expert testimony, and motions in limine. The court is preparing this case for trial even as PTAB proceedings continue in parallel — the court had previously issued a mixed ruling on IPR petitions and denied Bambu Lab’s motion to stay the district court litigation pending PTAB decisions.

The Court’s Holding

§ 101 patent eligibility — mixed results, all patents survive. Three summary judgment motions challenged multiple Stratasys patents under Alice. For the foundational FDM build-path patent (U.S. Pat. No. 7,555,357), the court denied Bambu Lab’s motion outright at Alice Step 1, finding the claims address a specific technological problem — comparable to the software improvements upheld in DDR Holdings and Enfish. For the tagged-material patents (Nos. 10,569,466 and 11,167,464, covering RFID/optical tags on filament spools that auto-configure printer parameters), the court found the claims directed to an abstract idea at Step 1 but denied summary judgment because genuine fact issues remain under Alice Step 2 as to whether the ordered combination of claim elements represents an inventive concept beyond routine activity.

Claim 7 of the heated platform patent (U.S. Pat. No. 9,592,660) found indefinite. Bambu Lab’s motion for summary judgment of invalidity of claim 7 was granted. The court had previously found the term “thermally conductive plate” indefinite in claim 1 at Markman. Because claim 7 added only material specifications (aluminum, steel, brass, ceramic, or low-CTE alloys) and those additions could not cure the predicate indefiniteness of the underlying term, claim 7 falls with claim 1.

License defense clears all patents except No. 7,555,357. The court granted Stratasys’s motion for summary judgment on Bambu Lab’s license defense as to all asserted patents other than the ‘357. For the ‘357, genuine disputes of fact remain — specifically, whether Stratasys controls its MakerBot and WidowMaker subsidiaries and whether Bambu Lab materially modified open-source code (ReplicatorG, Slic3r) in a way that would trigger or foreclose a patent license under the applicable open-source agreements. That issue goes to the jury.

Stratasys damages expert takes significant hits. The court struck three categories from Stratasys’s damages expert: (1) his survey-based apportionment figure yielding 51% value allocation — excluded for lack of a reliable quantitative methodology; (2) convoyed sales opinions — excluded for lack of nexus to the asserted patents; and (3) future royalty opinions — excluded as speculative. The expert was given leave to supplement on apportionment. Bambu Lab’s damages expert survived intact.

Key Takeaways

• Tagged-spool patents survive § 101 on factual grounds. Even though the court found RFID-tagged filament claims directed to an abstract idea, the Alice Step 2 inquiry is fact-intensive enough to survive summary judgment when the patentee presents competent technical expert testimony about the non-obviousness of the ordered claim combination.
• Open-source license is a live invalidity defense. The ‘357 patent’s open-source license defense is a rare scenario where a competitor’s potential license under GPL or MIT-family open-source code could affect patent enforceability. The jury will decide whether Bambu Lab modified the code materially enough to change its license status.
• A damages apportionment model must be precisely tied to specific claims. A survey showing “51% of buyers cite patented features” is not enough; the expert must articulate a reliable methodology connecting survey responses to specific patented claim limitations.
• IPR stay denied — parallel tracks accelerate costs. With the district court proceeding to trial despite pending IPRs, Bambu Lab faces simultaneous proceedings at PTAB and in Marshall, Texas. Certain prior art references are now precluded at trial because they were the same grounds raised at PTAB.

Why It Matters

This case is shaping up as a landmark confrontation between the incumbent FDM pioneer and the most disruptive new entrant in desktop 3D printing. Judge Gilstrap’s rulings keep most of Stratasys’s portfolio intact for trial while removing Stratasys’s most aggressive damages theory. For the broader 3D-printing industry, the open-source license defense is the most intriguing subplot: if a jury finds that Bambu Lab’s printers run on materially unmodified open-source code originally developed at MakerBot, an entire generation of FDM patents could be subject to open-source licensing constraints that limit enforcement.

For patent practitioners, the order is a study in pretrial motion practice before Judge Gilstrap — one of the most experienced patent trial judges in the country. His approach to section 101 closely tracks the Federal Circuit’s bifurcated framework, and his enforcement of contention-disclosure deadlines reflects his case-management philosophy: expert testimony must track what was disclosed in contentions, with no late surprises.