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YOU CAN BUILD A PRINTER THAT MAKES POTTERY FROM RAW CLAY

A tilting clay printer that can overhang layers without support, built around an air compressor and an auger extruder.

by Joshua Bird

FULL CAD BOM FIRMWARE DOCS

WorkshopOpen-hardware

Built with3D printing

difficulty
●●●●●
time
several weekends
license
GPL-3.0 with restriction forbidding sale of files or derivatives
repo
repo ACTIVE915 stars

WHAT YOU’LL NEED

Videos
1
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COMPAREE VERDICT

This is a working clay printer with tilting-nozzle kinematics, but it is a reference design for someone who has built printers before, not a step-by-step kit. The repos give you the CAD, the firmware config and parts lists; the author says there are no written instructions yet and points to an online 3D model and the Discussions tab instead. You will need an air compressor and regulator rated for at least 120 PSI, a kiln to fire the prints, and the skill to commission RepRap firmware on custom kinematics. The licence forbids selling the design files or machines derived from them. The one thing most likely to go wrong is the extruder: clay consistency, air pressure, motor speed and nozzle size all interact, and there is no published tuning guide. If you have built a CoreXY or a delta printer from scratch and you already own a compressor and a kiln, this is an extraordinary project for several weekends. If you do not, expect months of iteration.

GOOD TO KNOW

  • —Printer files include Fusion 360 and STEP CAD, STLs, a KiCad project for the optional PCB build plate, and RepRap firmware configuration.
  • —Extruder repo has CAD, syringe adapter and a parts list (compressor 120 PSI minimum, NEMA 14 motor, standoffs, 0.5 l clay cylinder).
  • —No assembly guide, no wiring diagram, no tuning walk-through for the extruder or the pneumatic system.
  • —Printer licence is GPL-3.0 with an added restriction forbidding sale of the files or derivatives; the extruder repo has no licence at all.
  • —The author says in his video that the printer costs less than 300 dollars; on top of that you need an air compressor capable of 120 PSI, a kiln for firing, and experience commissioning RepRap firmware on custom kinematics.
  • —The 4-axis tilting kinematics are novel but undocumented — expect significant troubleshooting to match the video results.

Parts to buy

9 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • NEMA 14 motorFind
  • 120+ PSI air compressorFind
  • 0.5 l clay cylinderFind
  • Pneumatic fittingsFind
  • StandoffsFind
  • Linear railsFind
  • BeltsFind
  • Controller boardFind
  • Kiln for firing finished piecesFind

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Can I build this?

PrintSTLs for the printer frame; the extruder and syringe adapter come as STEP/Fusion files you export yourself; an optional PCB build plate (KiCad files) to have made, or use a sheet of MDF
BuyNEMA 14 motor, 120+ PSI air compressor, 0.5 l clay cylinder, pneumatic fittings, standoffs, linear rails, belts, controller board, and a kiln for firing finished pieces
Tools3D printer, soldering iron for the bed PCB, multimeter, air line fittings, and access to Fusion 360 or a STEP-compatible CAD tool if you need to modify anything
Skillsexperience building 3D printers from scratch, familiarity with RepRap firmware, pneumatic system assembly, and the ability to troubleshoot custom kinematics without a guide
Timeseveral weekends: one to print and assemble the frame, one for the extruder and pneumatics, and however long it takes to tune the firmware and extruder for consistent layers
CostThe author says in his video that the open-source printer costs less than 300 dollars and that he uses a 40-dollar AliExpress compressor; a kiln for firing comes on top if you do not have access to one.
SafetyThe printer runs from a 24V power brick; no mains wiring is needed. Pneumatic air at 120 PSI can cause injury if fittings fail or the line is mishandled. Clay dust during cleanup is a respiratory irritant; work in ventilation. Kiln firing involves high temperature and requires proper ventilation and separation from flammable materials.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

I Built a Clay 3D Printer that Prints Impossible Objects

Shows the printer in action: double-walled cups, a rock-climbing cup and chain mail, plus the drying, firing and glazing steps. No assembly or tuning footage.

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Gallery

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Read the printer README and the extruder parts list (Confirm you have access to the tools and the skill level required; there is no assembly guide.)
  2. 2.Source the air compressor and verify it can sustain 120 PSI(This is the part most likely to be underspecified or bought wrong; the extruder will not push clay reliably without it.)
  3. 3.Order the custom bed PCB from the Gerber files(Optional: the README says a sheet of MDF also works as the build plate.)
  4. 4.Print the frame and extruder STLs(Use a printer with a build volume large enough for the frame parts.)
  5. 5.Assemble the frame, install the extruder and pneumatic system, then flash the RepRap firmware(Expect to spend time troubleshooting the 4-axis kinematics and the extruder flow rate before you see results like the video.)

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

  • Buying an air compressor that cannot sustain 120 PSI: the extruder will not push clay consistently, and you will spend days chasing flow problems that are actually pressure problems.
  • Expecting an assembly guide: the repos contain CAD and a parts list, not step-by-step instructions. If you have never built a printer from scratch, this will take far longer than a weekend.
  • Underestimating the tuning required for the extruder: clay consistency, air pressure, auger speed and nozzle diameter all interact, and there is no published tuning guide.
  • Missing the licence restriction: the printer licence forbids selling the design files or machines derived from them, and the extruder repo has no licence at all.
  • Not budgeting for a kiln: the prints are raw clay until they are fired, so you need your own kiln or access to one.
  • Assuming the 4-axis kinematics will just work: the tilting nozzle is novel and the firmware configuration is a starting point, not a drop-in solution. Expect troubleshooting.

Do I need an air compressor?

Yes. The extruder uses pneumatic pressure to push clay from the cylinder into the auger. The parts list specifies 120 PSI minimum.

Can I sell prints made with this printer?

Yes, the licence restriction is on selling the design files or derivatives, not on selling objects you make with the machine.

How much does it cost to build?

In his video the author says the printer costs less than 300 dollars, and his compressor was a 40-dollar AliExpress unit. The extruder parts list asks for a compressor and regulator capable of 120 PSI or more. Firing needs a kiln, which is the big extra cost if you do not have access to one.

Is there an assembly guide?

Not a written one. The repos contain CAD, STLs, a parts list and firmware config; for assembly, the README points to an online 3D model you can explore and to the GitHub Discussions, where builders share what they learned.

What size prints can it make?

The README does not state a build volume; you can read it from the CAD model or the axis limits in the firmware config.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

The video shows double-walled cups, a rock-climbing cup and even chain mail printed in clay. If you had a clay printer and a kiln, what would you print first?

CompareeTEAM8d agoedited

Practical notes from our verification: the extruder is in a separate repo (jyjblrd/Ceramic-3D-Printer) with CAD files and a BOM but no licence file, so its legal status is unclear. The printer repo has about 915 stars, was last pushed in June 2025 and uses a custom GPL-3.0-based licence that forbids selling the files or derivatives. The README says there are no written instructions yet; it points to an online 3D model that shows the assembly and to the Discussions tab, which is the best place for setup and tuning help. The biggest barrier is the skill floor: if you have never commissioned RepRap firmware on custom kinematics, plan for a long project. Get the air supply right before you start: the extruder BOM calls for a compressor and regulator capable of 120 PSI or more. 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.

Joshua Bird

Joshua Bird designed the Core R-Theta, a 4-axis polar printer whose tilting nozzle lets it print overhangs without support, and later built a pneumatic clay extruder for it. The printer and extruder repos share the CAD and firmware for others to replicate the build.

GitHub

Star the project on GitHub

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.
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