E20 Resources

E20 Competition Dates for 2024:

(Please confirm before travelling)

Buckminster Mondays

CD Luke Goymour - Open E20 and NFFS Rules

  • 29th April

  • 20th May

  • 17th June

  • 29th July

  • 2nd September

Sam 35 Events with E20:

CD Andy Green

  • Sunday 14th April Buckminster Spring Gala

  • Saturday 18th May Old Warden MayFly

  • Sunday 16th June Buckminster Retrofest

  • Saturday 27th July Old Warden Scale Weekend

Peterborough Flying Aces

Saturday 14th September (Many FF classes including Open E20)

PMFC Ferry Meadows Series

A monthly midweek club competition including Open E20. Visitors require BMFA membership.


E20 Rules:

The Peterborough MFC have flown with a few different E20 rules over the years. The original class was known as Ferry 500 using a specific motor & battery. In 2019, the broader Open E20 Rules were established to allow any motor set up. In 2022 members began experimenting with the US-style NFFS E20 Rules, which specify an 8.5x20mm coreless motor and single cell LiPo.

Most PMFC Ferry Meadows competitions are flown with the Open E20 Rules which suit small fields. The Ferry 500 rule is now obsolete, but these models can still enter the Open class. Monday competitions at Buckminster and International Postals include events for both Open E20 and NFFS Rules. NFFS Rules are likely to be adopted for future competitions in the UK.

Open E20 Rules (2024)

This is an electric free flight development class where experimenting with different power systems is encouraged.

Models must have a maximum 20" projected wingspan (the previous maximum 20" overall length rule has been dropped.)

Any motor, battery, propeller and timer are permitted.

Motor run will be less than 8 seconds.

Models must have a dethermalizer fitted.

No minimum or maximum model weight.

Competition comprises of three flights to a max decided on the day (up to 60 seconds.) A flight of less than 10 seconds will be considered an attempt.

NFFS E20 Rules

US-Style E20 with a restricted motor and battery.

Maximum projected wingspan: 20 inches

Minimum Weight: 28.4g (1oz)

Motor: 8.5mm x20mm Coreless, no gear drives

Battery: Single Cell LiPo (no capacity limit)

Propeller: maximum 2.7” diameter

Motor Run: 20 seconds (Fly offs 10 seconds)

No auto-surfaces other than dethermalizer

Three flights to a 90 second max, Fly off max increases in 30 second intervals

Full Rules can be found at the National Free Flight Society: https://www.freeflight.org/free-flight-rules/

International Postal Competition Rules

can be found at: https://www.e20world.com/postal-winter-warmer-23-24

Ferry 500 Rules (Historical)

This is an electric free flight class flown on a fixed power system to provide a level playing field for small field competition.

Models must have a maximum 20" projected wingspan (not flat span) and a maximum 20" overall length including propeller.

Any airframe design is permitted within the above limits.

Models must fly with a specified motor, propeller and timer.

For the 2019 competitions these will be:

GWS CN12-RXC 7.2V or N60 25500RPM 6-7.2V 12mm brushed can motor

3x2" direct drive prop

Peterborough FET fixed motor run timer (details here: https://peterboroughmfc.org/Ferry500-Timer.html )

Battery must be a minimum of 2S 180mah Lipo.

Motor run will be fixed at approximately 8 seconds.

The timekeeper is responsible for ensuring the motor run in flight is 8 seconds or less.

Models must have a dethermalizer fitted.

No minimum or maximum model weight.

Competition comprises of three flights to a max decided on the day (up to 60 seconds.) A flight of less than 10 seconds will be considered an attempt.

For 2019 the motors are available to PMFC members on proof of a viable model. The recommended battery is a Turnigy Nanotech 2S 180mah (25-40C)

(Ferry 500 is no longer flown by the PMFC as a separate class but the rules are included here for historical interest.)


Index of PMFC Resources

Jonathan Whitmore's Idiom E20 Plan and information:

https://peterboroughmfc.org/feature/idiom

E20 Rules: https://peterboroughmfc.org/FlyingRules/Ferry500-E20.html

Ian Middlemiss' 2013 Experiments with E20:

https://peterboroughmfc.org/membersmodels2013/04Smallfielesff.htm

https://peterboroughmfc.org/membersmodels2013/08Smallfielesff-two.htm

https://peterboroughmfc.org/membersmodels2013/11-E20_3.htm

2014 Competition Proposal:

https://peterboroughmfc.org/membersmodels2014/01-E20.htm

2014 Competition Progress Report:

https://peterboroughmfc.org/membersmodels2014/08-E20-progrep.htm

E20 Competitions re-established in 2018:

https://peterboroughmfc.org/technical-articles2018/E20Competition.htm

https://peterboroughmfc.org/technical-articles2018/E20-FurtherInfo.htm

PMFC Magazine Report:

https://peterboroughmfc.org/newsletters/2018-01-Leading_Edge-A5.pdf

Peterborough FET Timer Index Page:

https://peterboroughmfc.org/technical-articles2018/FET_Timers_consolidation.htm

The Ferry 500:

The 2019 AeroModeller Plan

https://peterboroughmfc.org/Ferry500.html

Ferry 500 FET Timer tutorials

https://peterboroughmfc.org/Ferry500-Timer.html

Luke Goymour’s E20 talk for the BMFA ‘In The Air Tonight’ Series:


E20 Kits, Plans & Components:

BMK Free Flight Store (UK Timers, Chargers etc): https://bmks.co.uk/collections/e20-timers-parts

J&H Aerospace (US Kits, Motors etc): https://jhaerospace.com/product-category/free-flight-kits/electric-freeflight

Joshua Finn’s Youtube Channel (Including videos for J&H Aerospace E20 kits): https://www.youtube.com/@joshuawfinn

Component Shop (UK LiPo’s): https://www.componentshop.co.uk/batteries/radio-control/li-po-flight-packs/3-7v-1s-packs.html

Mariusz Wrona – Fatcat 2, 3 Kits (Poland): https://www.facebook.com/mariusz.wrona.77

Vintage Model Company SAMS E20 Kit: https://www.vintagemodelcompany.com/sams-e20-free-flight-duration-model

Ralph Bradley Thermite Plan: http://parmodels.com/thermite-e-20-by-ralph-bradley

Ralph Bradley Cliché Plan: http://parmodels.com/cliche-e20


Useful Links:

Facebook E20 Free Flight Group: https://www.facebook.com/groups/252734703568141

Luke Goymour’s E20 site (Postal Competitions): www.e20world.com

The original Hip Pocket Aeronautics Forum E20 thread (Currently only available via Wayback Machine): https://web.archive.org/web/20210620223000/http://www.hippocketaeronautics.com/hpa_forum/index.php?topic=14519.0

Current Hip Pocket Aeronautics Forum E20 thread: https://www.hippocketaeronautics.com/hpa_forum/index.php?topic=27299

Willamette Modeler’s Club: http://willamettemodelersclub.weebly.com


Further Reading

Aeromodeller E20 Coverage:

November 2018 Peterborough Flying Aces Demo Andrew Boddington

June 2019 Ferry 500 Plan Feature Jonathan Whitmore

February 2021 GTS-E20 Review Chris Edge

June 2022 E20 Events Chris Edge

August 2022 2022 Mini Nats Report Chris Edge

August 2022 International Postal Reminder

November 2023 SAMS E20, BMK Timers Stuart Marsden

E20 Development Series: March 2024 1. The E20 Story (Class History) Jonathan Whitmore April 2024 2. E20 Design and Performance Jonathan Whitmore May 2024 3. E20 Idiom Free Plan Feature Jonathan Whitmore

National Free Flight Symposium #48 (2015)

An account of the origins of the US E20 class: “The E-20 Story – One of Free Flight’s Newest Events – Bob Stalick, Various Authors” https://www.freeflight.org/complete-symposium-contents

Free Flight Quarterly:

FFQ #62 - Bob Selman - 'Micro Pearl' (Depron)

FFQ #68 - Ralph Bradley - 'Cliché'

FFQ #70 - Ralph Bradley - 'Magnetic Propeller Brake For E20'

FFQ #74 - Ralph Bradley - 'Thermite'

FFQ #82 - Stan Buddenbohm - 'PushE' (inc. Plan)