OpenFixture

Goal

The motivation of OpenFixture was to make a parametric fixturing system that could take fully generated inputs from kicad and produce a test fixture with minimal effort. The easiest way to use it is through the kicad python scripting interface.

Parameters

For most projects (if using the standard BOM) the only parameters you'll need to set are mat_th and pcb_th. Something like the following should be sufficient:

./GenFixture.py --board [path to board.kicad_pcb] --mat_th [thickness in mm] --pcb_th [thickness in mm] --out board-fixture

usage: GenFixture.py [-h] --board BOARD --mat_th MAT_TH --out OUT
                     [--pcb_th PCB_TH] [--screw_len SCREW_LEN]
                     [--screw_d SCREW_D] [--layer LAYER] [--flayer FLAYER]
                     [--ilayer ILAYER]

optional arguments:
  -h, --help            show this help message and exit
  --board BOARD         <board_name.kicad_pcb>
  --mat_th MAT_TH       material thickness (mm)
  --out OUT             output directory
  --pcb_th PCB_TH       pcb thickness (mm)
  --screw_len SCREW_LEN  Assembly screw thread length (default = 14mm)
  --screw_d SCREW_D     Assembly screw diameter (default=M3)
  --layer LAYER         F.Cu | B.Cu
  --flayer FLAYER       Eco1.User | Eco2.User
  --ilayer ILAYER       Eco1.User | Eco2.User

The resulting output is:

A 3D model of the test fixture for visualization
A 2D DXF that can be directly lasercut for assembly

Recommended workflow for kicad

Clone this repo if you haven't already
Setup a project specific bash script (use genfixture.sh as an example)
Enter board specific info, fixture hardware, material thickness, etc.
Whenever the layout changes call ./genfixture.sh (from repo) and pass path to .kicad_pcb file.
Fixture will be generated in $OUTPUT folder.
If anyone is interested in integrating this into kicad directly I'd be happy to support it and clean it up...

Hardware

All that is needed is M3 (14mm+) screws, M3 hex nuts, and lasercut parts
I use nylon bushings in the main pivot with m3 screws for a smoother joint but this is optional

Documentation

http://tinylabs.io/openfixture

BOM

http://tinylabs.io/openfixture-bom

Kicad export

http://tinylabs.io/openfixture-kicad-export

Assembly

More info including detailed assembly instructions at http://tinylabs.io/openfixture-assembly

Dependencies

Newer version of openscad >= 2015.03-1
kicad or other EDA software. Please email me if you have instructions for other packages so I can add them.

Known Issues

When loading the fonts file a new small window opens in Ubuntu. Seems innocuous but still annoying [Only seen on ubuntu 14.04]

License

Creative Commons (CC BY-SA 4.0)

Contributors

Elliot Buller - Tiny Labs Inc

Please email with any pull requests or new feature requests elliot@tinylabs.io

matt-chaney/openfixture