Foil-Design-Tool

Foil Design Tool and B-Series Propeller for Onshape

Two free, parametric toolsets for Onshape, for people who design and build their own hydrofoils and propellers. Both run in a free Onshape account, both make the 3D-printable molds to build the parts in carbon, and both come with a user guide and an AI assistant that reads their output and suggests what to change next.

By JB69. Licence CC BY-NC-SA 4.0: use them, copy them, change them, not commercially, and share changes alike.

  Foil design B-Series Propeller
Search custom features in Onshape for Foil designer B-Series Propeller
Features Foil wing, Foil stabiliser, Foil performance, Foil mast, Foil fuselage, Foil mold B-Series Propeller, Universal B-Series Blade Engine, Propeller mold, Propeller model from part, Core forging mold
Guide Foil_Design_Tool_Guide.pdf BSeries_Propeller_Guide.pdf
Everything in one download foil-design.zip propeller.zip
Browse the files foil-design/ propeller/
AI assistant foil-design-assistant, in the zip propeller-design-assistant, in the zip

Foil design

Give it an area, an aspect ratio and a handful of shape choices, and it builds the front wing, stabiliser, mast and fuselage, runs a speed sweep of lift, drag, trim, stability, structure and power (with a propulsion group for eFoil and foil assist), and generates printable mold shells, a layup schedule and fabric cutting templates.

  1. Foil wing: area-first planform, NACA or tabulated sections with a tip section blended along the span, sweep, tip drop, washout, and the joint to the fuselage.
  2. Foil stabiliser: the same geometry, placed by arm, with a mount pad.
  3. Foil performance: no geometry; the speed sweep and the propulsion group.
  4. Foil mast: tapered, with fillet, optional motor pod and board plate.
  5. Foil fuselage: a round tube or a hub body, seated on the stab’s mount.
  6. Foil mold: two-part printable molds with keys, pinch-off, plugs, tiling, clamps or bag, the layup, cut templates and core molds.

Every number it produces is a steady-state estimate. Trust the trend from one variant to the next; treat absolute numbers, stall speed especially, as optimistic until you’ve checked them against a foil you’ve ridden. The guide explains how.

B-Series Propeller

Give it a diameter, a pitch, a blade area and a blade count and it builds a fixed or folding propeller on Wageningen B-series blades with its hub and mount, checks it against your motor and battery, and makes the mold to lay it up as one carbon part.

  1. B-Series Propeller: a complete fixed or folding propeller with its hub and mount (bore, keyway or bolt circle), and an optional printed hub core for a carbon layup. The folder has pins or captive bolts, bosses, stops, tail relief and a fold check.
  2. Universal B-Series Blade Engine: one blade for a hub of your own.
  3. Propeller mold: a printable matched mold for a fixed propeller, with hub sectors for the undercuts beside the roots, pinch-off, clamps or a vacuum bag, release checks, the layup and cut templates.
  4. Propeller model from part: measures a propeller drawn in any other CAD, imported as a STEP, so the mold can take it.
  5. Core forging mold: a printed piston press for forging the hub core in chopped carbon.

The operating check is an open-water estimate from the B-series polynomials, about ±20 %. Use it to compare designs and to catch a mis-sized drive before a print; trust your own logs over it.

Getting started

  1. In any Part Studio, open Add custom features, search for Foil designer or B-Series Propeller, and add the one by Jason Bird. Copies of older builds exist; the one by Jason Bird is current. Right-click any feature and choose Open linked document for the public Onshape document with its guide.
  2. Read the guide’s quick start, then change one or two things at a time.
  3. Turn on Log inputs (foil) or Print to notices (propeller). That text is what you read, compare and paste when asking for help.

The AI assistants

Each zip has an assistant/ folder with a skill for AI assistants. Paste a log and it explains the results, checks them against target ranges, and recommends a few changes in the dialog’s own labels, with the expected effect and the cost.

What’s in each zip

foil-design.zip propeller.zip
foil_design.fs, the Feature Studio source bseries_propeller.fs, the Feature Studio source
docs/: the guide PDF and its source, the charts, every parameter docs/: the guide PDF and its source, its images, every parameter
assistant/: the skill, its scripts, the portable version assistant/: the skill, its log reader, the portable version
examples/: a full console log and speed sweep  
LICENSE LICENSE

The Feature Studio source is only needed for your own copy; the published features are added in Onshape by search.

Feedback

Issues and suggestions here, or on foil.zone in “Going down a rabbit hole - Parametric foil design and printable molds in Onshape” (the foil tool) and “Three-Blade Folding Prop Experiment” (the propeller).