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recently added:  turns calculator
see SAM 35 Speaks - June 2016 page 10

also:  balsa density calculator 


best Indigo result so far:

Bruce has posted a time of 4:28s set on 2016_02_20
 - previously he had posted a time of 3:56s set on 2015_12_05 using 0.070" rubber

Garry Flack, also of IVCMAC, had previously posted a time of 2:50s





Clive King believed that the future of popular indoor flying was in the use of local sports halls. His series of articles in Aero Modeller , covering the skills needed and a suitable design for flying in such sites, are a lasting contribution to the hobby he loved.

Indigo Postal CompetitionClive King

Aero Modeller will promote a postal competition for Clive King's Indigo design It will run for 12 calendar months and be administered by IVCMAC Andrew Boddington, Editor of the Aero Modeller, has offered a prize as well as agreeing to run regular updates in tha pages of the magazine



Indigo plan
A free copy of this plan was included in the Nov 2015 Aero Modeller

you can download the plan full size (A3 pdf) here


Part 1 March 2015 
"New columnist Clive King introduces us to the skills and science of indoor duration flying."
Part 2 April 2015   
"Clive King continues his introduction to indoor duration flying."
Part 3 May 2015    
"Clive King goes into more detail about rubber motors and propellers for indoor duration."

Part 4 July 2015     
"Having dealt with the basic indoor flying procedures and making the best use of the associated equipment to improve your existing models performance, Clive King now begins to discuss concepts that will prepare you for INDIGO, soon to be featured as a full size plan for you to build for the next indoor season."
Part 5 August 2015
"Clive King gives advice on covering materials and techniques for indoor models."

Part 6 October 2015
"Clive King looks at preparing different classes of Indoor models for optimum performance."
Free Plan November 2015
"Clive King has designed the Indigo to allow the average club indoor modeller to progress with their duration flying."
Part 7 December 2015
"Clive King completes this series on indoor duration models by giving hints and tips on flying Indigo the Free Plan in the last issue."

back issues of Aero Modeller can be bought from ADH publishing

building a simple Torque Indicatortorque indicator

A design for a quick and easy Torque Indicator can be downloaded here


automating a winderwinder

Design notes can be downloaded here




balsa density calculator

enter values for size and weight

width mm  
length mm  
thickness mm  
weight g  


lb/cu ft 

example: a 3" sheet of 3/32" balsa weighs 15g
when measured it is 76mm wide, 915mm long and 2.4mm thick
entering those values into the claculator and clicking on 'calculate' we get 5.61 lb/cuft

light or soft is anything between 4 and 5.5 lb/cuft
medium goes from 5.5 to 6.5 lb/cuft
heavy or hard ranges from 6.5 to 9.5 lb/cuft though some is more dense still

spruce is around 28 lb/cuft






turns calculator

enter values for length and weight

length inches  

weight g  


calculated turns 

example: a 30g motor of un-stretched length 29 ins
entering those values into the claculator and clicking on 'calculate' we get 1,255 turns



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