YOU CAN BUILD THE MACHINE THAT 3D PRINTS HEART TISSUE — FRESH BIOPRINTER CONVERSION FOR UNDER 900 DOLLARS
A low-cost desktop 3D printer becomes a collagen bioprinter for under 900 dollars in total, built by the lab that developed the FRESH method used to print a full-size model of a human heart.
by Feinberg/Shiwarski lab, Carnegie Mellon University
ScienceOpen-hardware
Built with3D printing
- difficulty
- ●●●●○
- time
- a weekend-plus
- license
- CC BY 4.0
- repo
- repo ACTIVE0 stars
●●●●○ · a weekend-plus · CC BY 4.0 · 0 stars · repo ACTIVE
WHAT YOU’LL NEED
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COMPAREE VERDICT
This is the Carnegie Mellon lab's own recipe for turning a low-cost FlashForge Finder into a FRESH bioprinter: the stock board is replaced with a Duet 2 WiFi, and the filament extruder with their Replistruder 4 syringe pump, driven by the printer's original extruder motor. The paper puts the total under 900 dollars and reports travel accuracy better than 35 µm in all three axes, with collagen lattice prints averaging under 2 percent error and a collagen ear printed from scan data. The machine is the easy part. The FRESH support bath is a lab protocol (gelatin microparticles, centrifuging, degassing) and the collagen bioink is a research product, so check what you can actually source and process before you start. What you get is a validated research tool at a fraction of the price of commercial bioprinters, which the paper says range from 5,000 dollars to over 1,000,000 dollars.
IN THE REPO
GOOD TO KNOW
- —Complete CAD (24 MB) for FlashForge Finder conversion and Replistruder 4 syringe extruder on Zenodo under CC BY 4.0.
- —Full bill of materials and step-by-step conversion procedure published in open-access Scientific Reports paper (PMC9805454).
- —The stock controller is replaced with a Duet 2 WiFi board; you configure its firmware through the Duet web interface, step by step in the paper's guide.
- —You print collagen and hydrogel scaffolds at home; printing living tissue requires cell culture facilities not covered in the build.
- —The base FlashForge Finder printer has to be sourced separately; the paper puts the whole conversion, printer included, under 900 dollars.
- —CC BY 4.0 licence permits commercial use with attribution.
Parts to buy
7 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.
Videos
Carnegie Mellon College of Engineering video about the lab's FRESH heart bioprinting research. It shows the method, not this FlashForge Finder conversion; there is no build video for the conversion.
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Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the full conversion paper (Scientific Reports open-access paper with complete build procedure, BOM, and troubleshooting)
- 2.Download the CAD files (24 MB Zenodo archive with FlashForge conversion parts and Replistruder 4 syringe extruder CAD)
- 3.Source the base printer(The FlashForge Finder is the documented base and is mostly available used. Carriages for the MakerGear M2 and LulzBot Mini 2 are also on Zenodo, and the lab is moving its workshop build to the Creality K1 SE.)
- 4.Order syringe pump components(The Replistruder 4 reuses the Finder's extruder motor; most of its parts are 3D printed and the rest is common hardware listed in the Replistruder files on Zenodo.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- The FlashForge Finder is hard to find new — expect used units and varying prices. The Zenodo files include carriages for the MakerGear M2 and LulzBot Mini 2 if Finders dry up.
- Collagen bioink and support-bath materials are research products from suppliers such as Advanced Biomatrix, Fisher and Sigma-Aldrich. The paper names them but says nothing about availability outside the US, so check what you can order before you start.
- You are printing scaffolds, not living tissue. Cells require sterile hoods, incubators, and training the build does not cover. If you lack lab access, the prints will be structurally impressive but biologically inert.
- Gelatin bath preparation is half chemistry, half trial-and-error. The paper gives the recipe, but temperature, mixing time, and degassing all affect print quality. Expect the first few batches to fail.
- The conversion assumes you already own a 3D printer to fabricate the custom parts. If you do not, you will need to order them from a print service or find a makerspace.
- No official support forum exists. The paper's corresponding author email is listed, but this is a research publication, not a product with a helpdesk.
Can I print living tissue at home?
No. You print collagen scaffolds. Living cells require sterile facilities, incubators and cell culture training not covered in this build. The lab notes the printer is small enough to fit in a biosafety cabinet, but the biological side needs a lab.
What if I cannot find a FlashForge Finder?
The Zenodo files also include carriages for the MakerGear M2 and LulzBot Mini 2, and the lab is updating the design for the newer Creality K1 SE, so you are not locked to a used Finder.
Where do I get collagen and gelatin?
The paper uses gelatin Type B from Fisher Chemical, Pluronic F-127 and gum arabic from Sigma-Aldrich for the support bath, and LifeInk 200 collagen from Advanced Biomatrix. These are research-supplier products; depending on your location you may need a research or university account to order them.
Is the licence commercial-friendly?
The design files on Zenodo and the paper are CC BY 4.0, which allows commercial use with attribution. But the paper notes that the FRESH printing method itself is patent-protected and commercialised by FluidForm, so check the patent position before using it commercially.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
The conversion is cheap; the biomaterials are the hard part. What is the research-grade collagen and gelatin sourcing situation where you are?
Feinberg/Shiwarski lab, Carnegie Mellon University
This conversion was published by the Carnegie Mellon bioengineering team that developed the FRESH bioprinting method and printed the first full-size 3D model of a human heart. The open-source release brings the same technique within reach of small labs and serious makers.
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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.
CompareeTEAM1mo agoedited
Practical notes from our verification: the project homepage (3dbioprint.org/bioprinter) hosts the overview and links to Zenodo and the paper, but there is no GitHub repo — all files are on Zenodo under doi 10.5281/zenodo.7496012. The documented build is a FlashForge Finder with the Replistruder 4 syringe extruder and a Duet 2 WiFi controller replacing the original board, so you will be configuring RepRapFirmware, not just swapping mechanical parts. Alternative carriages exist for the MakerGear M2 and LulzBot Mini 2, and the lab is updating the design to the Creality K1 SE. The paper puts the conversion under 900 dollars, against 5,000 dollars and up for commercial bioprinters. The biggest non-obvious hurdle is biomaterial sourcing: research-grade collagen and support-bath materials are not supermarket items, so check what you can actually order before you start. Photo note, 22 August 2026: this page had no images. We added 2 photographs of this specific build, each credited above; nothing here is a stock shot or another project. 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.