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Posted by knlever | May 28, 2014 @ 04:51 AM | 1,936 Views
An outline of my future plans should help understand my posts

Projects Estimated Completion

Rubber Powered Model 2014
Rubber Powered RTP scale model 2014
RC RTP 2014-2015
Racetrack Pattern RTP 2014-2015
Scale Catapult Jet Gilders 30 cm span 2014
RC Gider modelled after jet 1 metre + span 2016-2017
Posted by knlever | Sep 17, 2010 @ 10:44 AM | 2,636 Views
In case you are wondering:

I have built and flown the following models

Limited Success:

- Monogram foam Cessna 180 ( Yes it is from the late 1970s!)

- Guillows Me 109 - Similar to this one at RC groups

( Two flights or so before it crashed. I still have the wing)


- Foam spitfire ( Picture not available) see similar P-51 here

- 1:26 Paper and card Cessna 180
Posted by knlever | Jul 24, 2010 @ 05:07 AM | 2,788 Views
1) The HLG has flown, and although not exactly scale, it proves the concept. Thinking of the next model.

2) The cardboard, bamboo and paper wing has been sucessfully tested on the stick rubber powered plane, I had to add an extra rubber band for more power and flies satisfactorily - a short 15 metre flight or so but entertaining enough.

Now to build a scale fuselage and make that fly. Plan - Do - Study - And... I forget the next Adjust? Works for me.

I am looking at the set of vintage sheet balsa kits ...
Posted by knlever | Jul 23, 2010 @ 08:39 PM | 3,507 Views
Can alternative materials replace sheet balsa? The answer is yes, and it has in some cases, but what about weight?

Some free flight sheet balsa models use sheet balsa, and balsa has a density of between 5 and 10 lbs per cubic ft. ( 88 - 160 kg per cu metre)

A sheet balsa wing of 12 inches span and 3 inches wide ( 30 cm by 7.5 cm ) will weigh about 1.6 g and can be replaced by three bamboo spars and covered with 80 gsm paper. The paper will weigh 0.0225 sq metres weighing 1.8 g. What will the bamboo spars weigh?
Twice or more the density of balsa, so say Bamboo 300 - 400 kg/ Cu metre.

Volume of the spars : 30 cm x 1mm x 1 mm = 0.0000003 cu metres, and will weigh 0.36 g

So we have: balsa wing weight: 1.6 g
80 gsm paper weight for the wing area: 1.8g
Tissue paper weight for the wing area : 0.9g
40 gsm tissue paper wing with bamboo spars 1.26g
80 gsm paper with wing bamboo spars 2.16g 35% heavier

Cardboard is about 7 times the density of balsa, so using cardboard sheet and cutting out 1/7 of the area or more and covering with the 80gsm or tissue paper will result in a fairly light wing.

For sheet models such as those at Paul Bradley's Model Airplane Plans Page using cardboard and tissue is a possibility.

Posted this in my scale free flight thread also, but this is a simplified version

These links will take you to the data :



Balsa 88 kg/ Cu metre
Bamboo 300 - 400 kg/ Cu metre
Cardboard 680 kg/ Cu metre

Paper weights per (grams per sq m)

10–35 gsm tissue paper
35–70 gsm lighter textweight
70–100 gsm medium textweight
Posted by knlever | Jul 20, 2010 @ 09:14 PM | 2,934 Views
Cardboard is one of the most abundant materials on Earth ( I think)

Decided to put all the links for cardboard planes here.

- Pizza box plane - amazing achievement - and you get a free Pizza as well. Ok that part is not free.

-The famous cardboard plane site- I cannot believe how good the models look-
see the 'model photos' links

-And those RC groups links

- And er Wattflyer

- Other sites

Cardboard Flying Wing. And it is 'Not Light'

New link.Must make this a thread:A patent for a type of MODEL AIRPLANE CONSTRUCTION using - you guessed it - cardboard!
Posted by knlever | Jul 20, 2010 @ 12:36 PM | 2,710 Views
Added a set of posts on problem solving - applying these problem solving techniques - for example the '5 whys' I came across in the course of my work, and root cause analysis may speed up progress which has been somewhat slow.

I hope that other modelers will benefit from this approach.
Posted by knlever | Jul 10, 2010 @ 08:39 PM | 3,161 Views
On RC groups - there are two distinct types of discussions I have started, one set of discussions related to theory and ideas, which has been very useful and can be considered closed.

The other set of threads concerns building of actual planes. I have stopped the free flight glider project temporarily to concentrate on building a rubber powered model plane out of cardboard.