WingHopper · Designer · Guide · Sections · Reef · Methods · Pricing · FAQ
The Foil tab sets the cross-section. The outline decides where the fin is; the foil decides how thick it is and which way the thickness faces.
| Type | Inside face | Where it is used |
|---|---|---|
| Flat | Flat, all the foil on the outside | Thruster side fins, keels on a fish |
| 50/50 | Symmetric | Center fins, single fins, every windsurf fin |
| 80/20 | Mostly outside, a little inside | Quad rears, some side fins |
| 70/30 | Between 80/20 and 50/50 | Quad rears, twins |
A side fin with a flat inside face is built left-handed and mirrored for the right side. The Mount tab's handedness control chooses which; symmetric foils ignore it.
Maximum section thickness at the base, in millimetres. The app caps it at 20% of the base chord: a short, thick request builds thinner than the slider says, and the metrics card reads the as-built value off the surface.
Tip thickness as a share of the base thickness. Lower tapers the section toward the tip.
Where along the chord the section is thickest, from 20% to 50% back from the leading edge.
The trailing edge is held to a minimum thickness so it can be printed or machined. A knife edge does not survive a slicer or a mill. The default is 0.6 mm.
Next: Mounts