YOU CAN BUILD THE BOX SURGEONS PRACTISE KEYHOLE SURGERY IN, FOR UNDER 150 DOLLARS
A Columbia University team rebuilt the 4,686-dollar trainer commonly used to prepare for the laparoscopic surgery (FLS) exam, for under 150 dollars in materials.
HealthOpen-hardware
Built with3D printing
- difficulty
- ●●●○○
- time
- a weekend-plus
- license
- CC BY-SA 4.0 (trocar: CC BY-NC-SA 4.0)
- repo
- repo ACTIVE1 stars
●●●○○ · a weekend-plus · CC BY-SA 4.0 (trocar: CC BY-NC-SA 4.0) · 1 stars · repo ACTIVE
WHAT YOU’LL NEED
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COMPAREE VERDICT
OpenTrainer is a complete laparoscopic surgery simulator that medical schools and residents can actually build. The repository is unusually thorough: the FLS task modules have STL and STEP files, the acrylic body has DXFs, there are Word assembly guides, a BOM with supplier links, and demo videos of tasks such as peg transfer and a bleeding-arteriole ligation. The team described the design in a peer-reviewed "How I Do It" article in the Journal of Surgical Education, which puts the commercial FLS trainer at 4,686 dollars. The under-150-dollar figure is materials only and does not include laparoscopic instruments, which are the expensive part and which you need at least two of to practise. The BOM links the smartphone endoscope the team used, so sourcing the camera is straightforward. The trocar files are non-commercial because they remix an existing Thingiverse design, which is fine for training but blocks selling kits. The single hardest part is not the build — it is sourcing or borrowing real laparoscopic instruments, because without them the trainer is just a box. If you are a medical student, resident, or part of a simulation lab, this is a legitimate low-cost alternative for FLS practice.
IN THE REPO
GOOD TO KNOW
- —BOMs, STL/STEP files for all 3D-printed modules, DXF files for laser-cut acrylic body, assembly guides and demo videos are in the repository.
- —The trocar (instrument port) files are CC BY-NC-SA 4.0 because they remix an existing design; all other files are CC BY-SA 4.0. Commercial use of the trocar design is restricted.
- —You still need real laparoscopic instruments (graspers, scissors, needle drivers) to train with; the build does not include or price them.
- —The BOM links the smartphone endoscope used (Useeplus-app compatible) and an alternative with a built-in display.
- —No firmware or code is required; this is a physical trainer with a passive camera feed to a phone.
- —Peer-reviewed "How I Do It" article in the Journal of Surgical Education (2026, PMC13526417) describes the design, materials and custom modules.
Parts to buy
6 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
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Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the README and the two assembly guides (Word documents) in the "Appendix C - Assembly Instruction" folder (Start here — the guide explains module assembly order and trocar seal fitting)
- 2.Review the BOM spreadsheet and source the acrylic sheets, fasteners and USB endoscope(The BOM links the endoscope used (Useeplus-app compatible); test any substitute with your phone first)
- 3.Print all STL files for your chosen exam modules and the trocars(STEP files are also provided if you need to modify dimensions)
- 4.Laser-cut the acrylic body using the provided DXF files(The BOM specifies two 12×24 inch sheets of 1/8 inch clear acrylic)
- 5.Watch the task demo videos in Appendix D to see what the finished trainer should do(These show the trainer in use on the tasks (peg transfer, gauze cutting, appendectomy, bleeding arteriole), not the assembly itself)
KNOWN ISSUES
- The under-150-dollar cost is materials only. Real laparoscopic instruments (graspers, scissors, needle drivers) are not included, and you need at least two to practise, which can cost more than the trainer itself unless you borrow them from a medical school or simulation lab.
- The BOM links a specific smartphone endoscope that works with the Useeplus app. If you substitute a different model, you may need a different app and should check phone compatibility and image quality first.
- The trocar (instrument port) files are CC BY-NC-SA 4.0 because they remix an existing design. You cannot sell kits or use the trocar design commercially, even though the rest of the project is CC BY-SA 4.0.
- Trocar seals must fit tightly or instruments will not move smoothly. The assembly guide mentions this but does not give tolerances; if your printer over-extrudes, the seals will bind.
- Access to a laser cutter is assumed. If you do not have one, acrylic cutting services will add cost and a week of lead time. The DXF files are provided but cutting services charge per sheet.
- This is a training simulator, not a toy. If you are not a medical student, resident, or part of a medical education program, you will have no practical use for it and no way to validate that your build meets FLS exam task specifications.
Does this replace the commercial FLS Trainer for exam certification?
No. The FLS exam itself must be taken on an official FLS Trainer System at an accredited testing center. OpenTrainer is for practice before the exam, not for taking the exam.
Are laparoscopic instruments included in the build or the cost?
No. The build is the trainer box, camera and exam modules only. You also need laparoscopic instruments (graspers, scissors, needle drivers), which are not in the BOM and are the expensive part; many students borrow them from their school's simulation lab.
Which USB endoscope should I buy?
The bill of materials links the exact endoscope the team used: a smartphone USB endoscope that works with the Useeplus app (Amazon B0FC2HS5GZ), plus an alternative semi-rigid endoscope with its own display. If you pick another model, check it works with your phone before cutting the acrylic.
Can I sell assembled OpenTrainer kits?
Not without changing the trocar design. The trocar files are CC BY-NC-SA 4.0 (non-commercial) because they remix an existing design. The rest of the project is CC BY-SA 4.0, which permits commercial use with attribution, but the trocars are required to make the trainer functional.
How does this compare to the commercial FLS Trainer?
The commercial FLS Trainer System costs 4,686 dollars according to the paper. OpenTrainer replicates the exam tasks and adds custom modules (bleeding arteriole, appendectomy), using a smartphone endoscope, laser-cut acrylic and 3D-printed parts. The paper describes the design; it does not report a head-to-head study of training outcomes.
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Discussion1
FROM THE COMPAREE TEAM
The paper puts the commercial FLS trainer at 4,686 dollars, and OpenTrainer at under 150 dollars in materials, but you still need real laparoscopic instruments to train with. If you are a medical student or resident, where would you source or borrow them?
Arvind Nandakumar, Maria R. Hudock, Griffin Welsh Daly, Mohamed Diane, Meghal Shah, Daniel Naveed Tavakol, Gordana Vunjak-Novakovic
The team is from Columbia University's Department of Biomedical Engineering and Columbia University Irving Medical Center. They built OpenTrainer to make surgical simulation accessible to medical schools and residents who cannot afford the 4,686-dollar commercial trainer, and described it in a peer-reviewed "How I Do It" article in the Journal of Surgical Education in 2026.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM14d agoedited
Practical notes from our verification: the repository is thorough: BOM spreadsheets, STL and STEP files, a laser-cut DXF for the acrylic body, assembly guides as Word documents, and short videos showing the training tasks being performed. The paper (Journal of Surgical Education, 2026, PMC13526417) is a 'How I Do It' design report: it describes the build and its under-150-dollar materials cost, but it does not include a study of training outcomes. The single biggest cost trap is not in the repository: real laparoscopic instruments (graspers, scissors, needle drivers) are not included, and you need them to practise realistically. The BOM does link specific USB endoscopes that work with the Useeplus smartphone app, so check that compatibility before you buy a different one. The trocar design is non-commercial (CC BY-NC-SA 4.0) because it remixes an existing Thingiverse file, so you cannot sell kits that include it, even though the rest of the project is CC BY-SA 4.0. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.