“When you're racing against your own biology, the story is just the exhaust; the science is the engine and time is the fuel.”
Steady Hand Tool: Mechanical stability for a wandering hand.
Demonstrating the stability and precision of the Steady Hand Tool.
Steady Hand Tool is a manual SMD (Surface Mount Device) assembly stabilizer designed to help makers and professionals prototype PCBs with high precision. Originally created to overcome physical challenges—specifically hand tremors caused by Parkinson’s disease—this tool makes high-accuracy soldering accessible to everyone.
- Stabilized 4-DOF Movement: Keeps your hand on a steady track while allowing full vertical and horizontal reach.
- Near-Zero Friction: Equipped with 14 high-quality metal bearings and carbon fiber rods for smooth, silent, and effortless operation.
- Modular Magnetic Coupler: Features a quick-swap magnetic system for changing tool heads (tweezers, vacuum tips, etc.) in seconds.
- Purely Mechanical: No power required, no cables, and no noise. It's always ready to work when you are.
- Heavy-Duty Base: A weighted 680g (1.5 lb) base ensures the arm remains stable even at full extension.
- Open Source: Designed to be hacked and customized. Create your own tool heads to suit your specific workflow.
The Steady Hand Tool is coming to Crowd Supply.
Sign up to be notified when the campaign launches.
- Reach: Approximately 250 mm (9.8 in) vertical and horizontal travel.
- Construction: 3D-printed components (optimized for PETG/Carbon Fiber) and 8mm carbon fiber rods.
- Bearings: MR128ZZ precision shielded bearings.
- Compatibility: Designed to support a pair of specialized reverse tweezers optimized for 0805-size components and smaller.
Tip
Looking to build it? Check out our Assembly Guide for step-by-step instructions.
steady-hand-tool/
├── hardware/
│ └── models/
│ ├── stl/ # Printable parts and tool-head adapters
│ ├── 3rdParty/ # Adapters for third-party tools (PixelPump)
│ ├── 3mf/ # Print plates — orientation and slicer settings, not geometry
│ └── step/ # CAD-fidelity parts (being added part by part)
├── docs/
│ ├── assembly-guide.md # Step-by-step build instructions
│ └── magnet-polarity.md # The polarity standard every adapter follows
├── media/ # Photos used in the docs
├── BOM.md # Bill of Materials (the "Shopping List")
├── LICENSE # CERN-OHL-S-2.0 License text
└── README.md # This file
| Part | Notes |
|---|---|
SteadyHandTool-Pillar.stl |
Pillar |
SteadyHandTool-Spacer.stl |
The "fat" spacer — ⌀10.8 body on a ⌀8 spigot. One per bearing set (14 sets) |
SteadyHandTool-SpacerSmall.stl |
The "thin" spacer, same three diameters. One per bearing set |
SteadyHandTool-Stopper.stl |
Split clamp collar for an 8 mm rod, M3 cross screw |
SteadyHandTool-Aligner.stl |
Alignment jig used during assembly |
SteadyHandTool-InterfaceRing.stl |
The ring that interfaces with the tool head (assembly guide, Step 11) |
SteadyHandTool-Plate_STEADY_HAND_TOOL.stl |
Name plate (Step 12) |
SteadyHandTool-Plate_half_LOGO_marble.stl |
Logo plate (Step 12) |
InterfaceTweezers.stl, InterfaceManualVacuumPen.stl, InterfaceTemplate.stl |
Tool heads. InterfaceTemplate is the blank to start your own from |
Quantities per tool are in the assembly guide, not repeated here.
Not in this repo yet: the carriage (cage) assembly and the base. Every 3D model will be published when the campaign funds — that is the commitment, and it is part of what backing it pays for. Until then the BOM and the assembly guide describe those parts, and the magnet polarity standard is what any tool head you design has to match.
"It's the only tool that I have, to help me and others manage our own slice of PD hell."
The Steady Hand Tool is an engineering response to a personal biological war. It exists because "making" is a vital part of staying human. Inspired by the lived reality of Parkinson’s Disease, this tool is engineered to ensure that biological constraints never dictate the boundaries of human creativity.
This is a race against time and biology. We invite you to pick up a wrench and help us optimize the hardware for the next generation of makers facing similar constraints. Feedback, CAD iterations, and mechanical refinements are the high-octane fuel that keeps this engine running.
10% of the net profit from selling the Steady Hand Tool will go directly to support
Team Fox, the grassroots fundraising program of
The Michael J. Fox Foundation for Parkinson’s Research.
halfmarble is an independent Team Fox third-party fundraiser.
This project is licensed under the CERN-OHL-S-2.0 License - see the LICENSE file for details.
The license above covers this repository’s hardware designs and documentation. It grants no rights to any trademark, trade name, or logo — including the Team Fox and Michael J. Fox Foundation marks, and halfmarble’s own.
Photography: Hero images provided by Crowd Supply.