openGrid - Framefit Hook Generator

An open-source frame-fit hook generator for openGrid. This model attaches directly to the frame of an openGrid board, so it does not need a separate snap or openConnect connector. The default settings generate a compact hook for holding small objects, but you can create larger and stronger hooks by adjusting the parameters.

The recommended width for frame-fit hooks is under 20 mm. If you need wider or stronger hooks, check out the openConnect Sturdy Hook Generator.

Inspired by David D's openGrid Minimal Hook. The frame-fit snap shape is based on code adapted from BlackjackDuck's openGrid Tile Generator.

Several example .stl files are included, with the parameters used to generate them in the file names.

Customization guide

• Set "hook_vertical_grids". The default is 1 for a compact hook; increase it for a taller hook that grips more vertical openGrid frame sections.

• Choose "hook_corner_angle". Use "Horizontal" for a standard hook, or "Diagonal" when you want the hook body to angle upward from the frame.

• Adjust the hook reach. Use "hook_length" and "hook_tip_length". "hook_length" controls the overall length of the hook, while "hook_tip_length" controls how far the raised tip extends at the end.

• Adjust the hook cross-section. Use "hook_width", "hook_back_thickness", and "hook_bottom_thickness". Increase these values for a stronger hook. Adjust "hook_corner_fillet" to make the inside corner sturdier and smoother.

• Optional: add a bottom truss. Set "truss_vertical_grids". The default is 0 for no truss; increase it to add a bottom truss that helps the hook handle heavier loads.

• Optional: Set miscellaneous options:

• - "framefit_snap_clearance" - increase this if the frame-fit snap is too tight.

• - "hook_tip_angle" - adjust the angle of the tip.

• - "hook_tip_shape" - choose between "Round" and "Rectangular".

• - "hook_tip_corner_fillet" - adjust the rounding at the tip corner.

• - "hook_side_chamfer" - adjust the chamfer on the hook body edges.

The model is open-source under the CC-BY-SA license. Like all the OpenSCAD models I've designed for openGrid, it can be found in this GitHub repository. Feel free to use the code; feedback and suggestions are welcome.

2026-06-21 Update: Cleaned up the code and revamped the "hook_length" calculation.

2026-01-21 Update: Added an optional bottom truss for hooks that need to hold more weight. The truss is designed to print without supports, but you can enable supports if you are using a filament that bridges poorly. Thanks to @agentharm for the idea!

2025-09-14 Update: Added diagonal hooks and revamped the design.

Design and description by mitufy , licensed CC-BY-SA.