Polyhedral wing — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/polyhedral-wing/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
Catalog version: 2026-10-20

Sizes: see table below
- Polyhedral breaks the dihedral at more than one point, with tip panels steeper than the inner panels; McCombs calls it common on duration models.
- Because outer panels are farther out, they count more: McCombs combines breaks as an equivalent V-dihedral EVD = A + k*B, and Wainfan notes tip changes affect lateral stability more than root changes (Kitplanes).
- Rudder-only RC models need roughly 9 deg total effective dihedral to turn with rudder and recover (McCombs).
- The file is a reference example built by Xem Studio from the numbers above. Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

parameter  value or range  source
EVD formula  EVD = A + k*B (+ k*C ...)  McCombs, Model Aviation 1994
Worked example  A = 6 deg, B = 20 deg -> EVD 15.0 deg  McCombs 1994
Rudder-only RC total effective dihedral  about 9 deg  McCombs 1994
Hand-launched glider EVD  12-17 deg  McCombs 1994
Nordic towline glider EVD  9-12 deg  McCombs 1994
Reference build  span 1500, inner 6 deg (tips steeper)  McCombs example

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Model Aviation (AMA), W.F. McCombs: Wing and Tail Dihedral for Models (Dec 1994) — web — Publisher's page; dimensions are facts — https://library.modelaviation.com/article/wing-and-tail-dihedral-models
- Kitplanes (B. Wainfan): Wind Tunnel: Roll's role in lateral stability (2008) — web — Publisher's page; dimensions are facts — https://www.kitplanes.com/wind-tunnel-135/

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/polyhedral-wing/index.json
API: https://xemstudio.com/api/geometry?object=polyhedral-wing