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Pitch-to-diameter ratio

Name: Pitch-to-diameter ratio dimension sheet
Creator: Xem Studio
License: https://creativecommons.org/licenses/by/4.0/

What pitch-to-diameter ratio should I use for speed vs aerobatics? · Standard part · basis: Design rules and figures from the cited sources; example geometry by Xem Studio

Also called: pitch to diameter ratio, prop pitch ratio, square prop, low pitch prop 3d, high pitch prop speed, best prop for speed rc, best prop for 3d, p/d ratio propeller, pitch speed

Exact dimensions. True size, with no printing tolerance added.

sizes: 4 in table

Notes

Pitch ratio (pitch divided by diameter) sets what the prop is good at. APC recommends a near-square ratio such as 9x9 for high-speed use and a low ratio such as 13x4 for aerobatics and hovering (Model Aviation, APC Q&A).
Low-pitch props let the engine reach high rpm and maximum thrust at low speed, the same reason full-size constant-speed props use low blade angle for takeoff and higher pitch for cruise (FAA Powerplant Handbook).
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.

Pitch-to-diameter ratio size chart

parameter	value or range	source
Speed example	9x9 (P/D = 1.0)	Model Aviation (APC)
Aerobatics / hover example	13x4 (P/D = 0.31)	Model Aviation (APC)
Full-size takeoff vs cruise	low blade angle takeoff; higher pitch cruise	FAA Powerplant Handbook
Reference build	13 x 4, 2 blades	APC example

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

Model Aviation (AMA), J. Smith with APC Propellers	Common Questions with APC Propellers (Mar 2021)	web	Publisher's page; dimensions are facts
FAA	Aviation Maintenance Technician Handbook - Powerplant, Ch. 7 Propellers	web	Publisher's page; dimensions are facts

Free files

★ Free files 1 parts. Xem Studio design: free to use, print and sell things from; not to be republished as files. Xem Studio Design License. index.json

pitch-diameter-ratio-propeller

13×4 in propeller, 2 blades: each section set at the geometric pitch angle atan(P / 2πr); chord and section illustrative

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Plain text: sheet.txt · JSON: /api/geometry?object=pitch-diameter-ratio