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Posted by eagle60 | Aug 27, 2017 @ 10:24 AM | 3,228 Views
After I saw in a ChillPhatCat's post a pack of balsawood ribs for a wing I have been thinking a while of the possibility to use cheaper materials for this components. Actually in Italy Balsawood is expensive and for sure it is possible to save something at least for rectangular (untapered) wings.
First alternative material is depron, which is also very easy to work : cut as many rectangular pieces as required ribs just a little bigger than the ribs themselves; make 2 ribs in playwood or aluminum as per cutting a foam wing; pack everything together with 2 threaded bars (2 or 3 or 4 mm depending on the rib size); finally cut the ribs with the hot wire. You can foresee also the slots for the spars (make them a little smaller as the wire will "eat" some material and the spar must be tight) and also eventual lightening holes. Off course the depron could be 3 or 6 or other mm size depending on ribs and wings size.
The second alternative is to use foam, but not the normal white foam, the more compressed one (see photo) that could be found yellow, blue, green, pink and maybe more colours : you just cut a piece of wing with the playwood ribs previously described and then slice it on the thickness you need.
It should be simple and easy.
Posted by eagle60 | Jul 19, 2017 @ 09:09 AM | 4,820 Views
Material needed :
- polythene flexible sheet (the one used to cover the salad in the vegetable garden will do)
- 60 gr/m2 glass cloth
- 120 gr/m2 glass cloth
- packing paper light
- a small piece of nylon cloth
- epoxy resin
- pure alcohol (the one used for liquors 95%)
- off course the wings with the shells
- an old fridge or freezer compressor (must be working) to be used as vacuum pump
- plastic to make a sealed bag and tape to seal it

Cut a piece of polythene big enough to envelope the wing (top and bottom) and make an invitation bent on the line of the leading edge (photo 1).
Cut a piece of packing paper like the polythene size.
Cut a piece of 60 gr glass cloth like the polythene size.
Cut 2 triangular pieces of 120gr glass cloth with base half the wing central cord and high 3/4 of the wing span (photo 2)
Cut 3 squares 1"x1" of nylon cloth

Now take the polythene sheet, place on it the paper and the 60gr cloth on the paper (no wax or detatching agent is needed as the epoxy will not stick on the polythene).
Mix the resin and the catalyst and dilute with the alcohol (40% about). For each wing in the photos I did use 12 gr resin, 5 gr catalyst and 6/7 gr alcohol. In my opinion it is better to dilute the resin beause it will be more fluid and you will need less resin to soak the glass cloth; remember that all the weight you place in this operation will increase the wing weight, whilst the alcohol will go away.
Now soak the whole surface using as less resin as...Continue Reading
Posted by eagle60 | Jul 03, 2017 @ 01:12 AM | 4,627 Views
First you need a sound file of your flight. Remember that the closer the pass to the microphone the more precise will the estimation be. If the passes are too far from the microphone the frequency analysis (and therefore the speed result) will not be real.
Second you need a spectrogram progam, which can be downloaded from internet, but you can also find as app for android in the playstore. With this program you will see graphically (and read) the incoming (higher) and outgoing (lower) frequencies (remember that the more preccise the reads will be the more real the result will be).
Third you need to calculate the sound speed, which depends on local temperature (C) and humidity (%) of the moment (this latter is not much effective and could be ignored, but temperature is important as it could change results significantly), but this is included in the datasheet supplied herebelow. I suggest to separate the single passes audio and produce multiple frequency readings in order to have more speed computing which can give an idea of your model speed (input data are to be placed in the orange columns).
Hope this will be helpful for all those that do not want to put a gps data logger on the plane.
Finally remember that all the apps using Doppler effect to compute the speed of your model ignore the humidity datum and get the local temperature datum from the meteo system, that is why they require the gps to be on, therefore they can not be used on a second moment. If they do not ask the gps to be on do not trust their results.
Posted by eagle60 | Jun 12, 2017 @ 02:55 AM | 7,521 Views
I do not use more thickness than originals, as my goal is to acieve higher speed. Basically in the center I use a 17 cm (nearly 7") cord goe445 wich is simmetric and laminar with thickness increased to 7.4%, thus giving about 10 mm thick airfoil. On the tip I use a 11 cm (nearly 4 1/2") cord mh42 airfoil with thickness increased to 8.9 % to get an airfoil with the same thickness (in mm) as in the center with 1.7 negative incidence to get zero lift effect. In this way wings are neutral with constant thickness but absolutely no tip stall causing a sudden flip, if you slow the plane progressively increasing elevator up with no motor thrust it will start to sink flat.
All airfoils can be made with the program "profili" , which is free and can be downloaded here :

http://www.hoppenbrouwer-home.nl/ika...re/profi12.htm

The material used is not the normal polystirene (white) foam, but the more compressed one (see photos); you will barely notice the weight increase, but the strength will be much higher.
Now the strengthening tecknique depends on the weight of the model and the speed you want to achieve and if wings will be swept or not.
for speed up to 200 km/h (125 mph) and flying weight up to 600 gr (22 onces):
- On the swept wing I use a .8 mm piano wire rolled up the soldering iron (see photo) to cut a 3mm deep x 1mm wide slot top and bottom of the wings at the max thickness point for about the 2/3 or 3/4 of the wing span in which I glue with foam...Continue Reading
Posted by eagle60 | Mar 31, 2017 @ 10:18 AM | 6,710 Views
This story starts long ago: on the italian magazzine "Modellistica" of December 1993 I saw an article about an electric model designed by Joe Beshar, which I believe also cooperated later on with Lanier for the realization of their Shrike model.
I did like the geometry of the model and, with a friend of mine, decided to make one for a .40 glow motor, but changing some things :
- wing arifoil : I opted for a GOE 445 laminar and faster
- wing span : I went for 130 cm (52") to achieve surface enought extended to manage the extra weight
- fusolage : new in fiberglass to include some kind of karman.

The motor chosen has been a kwick 500 from supertigre which allowed the model to reach 130+ Mph.
Not only, but the model resulted also very maneuvrable and, despite its nearly 2.2 Kg (5 lb), with an excellent gliding capacity and on the top NO STALL (.... ok no significand stall: it just lowers the left wing of 1-2" and slides on that side regaining a little speed).
2 years later Lanier launched its Shrike.

Later on I made also a smaller version of about 80-90 cm (32-36") for a MDS .15 with resonance and the result has not been far from the bigger brother.

Today my son has one with the wing tips cut 5 cm (2") per side and with a MVVS 40 GRRT ( the very old pilon motor), which flyes at about 160 Mph.

white gas model plane (3 min 36 sec)


I am thinking about making a small one for an electric motor; we'll see.
At the end many thanks to Joe Beshar for its wonderful idea.
If you want the original lanier plans you can find them here:
https://outerzone.co.uk/plan_details.asp?ID=8900
https://outerzone.co.uk/plan_details.asp?ID=8886
Posted by eagle60 | Feb 28, 2017 @ 09:21 AM | 6,402 Views
Time for strange ideas : what happens if I add a couple of wings to a zeppelin baloon ( not full of gas) ? Will it fly ?
Peculiar item, but it flyes.
Posted by eagle60 | Jun 26, 2015 @ 09:06 AM | 7,480 Views
I did find the Elipsia model for the AFPD simulator and I have been impressed by its performance, so I decided to reproduce one. First step getting the plans, which I was not able to find in interned. Being it a fomie I thought it was enough to have the 2 views, side and top, to make it, so I entered the edit model mode on AFPD, placed the Elipsia on perfect top and side view and catched the image with proper software. Images have been reworked and placed on such dimensions that could be printed with the posteriza program ( my second post) on 3Wx5H horiz. paper for the top view and 5Wx1H vert.paper for the side view . Despite the obtained drawing are not perfect it is possible to built the model with some adaptations.
Flying exclusively outdoor I skipped the airbrakes on ailerons. The result is what you can see in the video ( pls consider that I am a terrible 3D flyer)

elipsia rough (4 min 34 sec)


sorry for the audio, but it was a windy day and there is some background noise.

More details
motor turnigy 2204-14T 19 gr
servo 3x4,7 gr
esc turnigy 10A
recever orange 6 ch naked
battery nanotech 2s 460 mA 25/40 C
all depron 3 mm
total weight 180 gr
Posted by eagle60 | May 01, 2015 @ 05:16 AM | 8,517 Views
Few years ago I bought from HK a cheap 55mm fan unit, but it came with a brushed motor allowing 90 gr thrust only. Then I bought a 24 mm inrunner with 4400 kv, but everything has been laying in a drawer up to last year. In fact, having seen the performance of the F 22 & the F 15, I decided to go for a try with a fan model. The choice has been of an Su 35, whom resized plans are enclosed. they can be printed with posteriza previously supplied in 2 sheets high x 3 wide.
all is in 3mm depron except for the skids which are 6mm depron
The results have been :
- wing span 45 cm
- total wight 250-265 gr
- battery lipo 3s 800 mA 30 or 40 c
- thrust 450 gr.
The performance can be seen in the following video :

su 35 mini (2 min 51 sec)


that fan unit is no more available, but in its place the following one could be used :


https://www.hobbyking.com/hobbyking/s..._Version_.html

or

https://www.hobbyking.com/hobbyking/s...W_4300kv_.html

Having seen how it flyes and the thrust the fan provides, I could have made it 25% bigger and sooner or later I will make one like this. also for this case I enclose plans, which will have to be printed in 3 sheets high x 4 wide.
Posted by eagle60 | Mar 19, 2015 @ 10:27 AM | 9,077 Views
Same consideration as per the F22 video. Plans posted early Jan.

F15 mini (2 min 17 sec)

Posted by eagle60 | Mar 05, 2015 @ 11:31 AM | 8,593 Views
The video has been made with my smartphone and the operator was not very skilled so pls forgive some "out of field" moments. Day was windy so the audio is slightly disturbed, despite I had to cut freq below 1.300 hz to reduce noise.
Overall you can have an idea of model performance capability.
Plans posted early Jan.

F22 mini (2 min 16 sec)

Posted by eagle60 | Jan 07, 2015 @ 10:03 AM | 9,589 Views
In the same way as the F22 I made also an F15 but the batteries ar below the wings level thus, with the reduced elevon area, inibiting the spin manovre.
But anyway, as the F22, it has unlimited vertical climbing and discrete speed for such a small plane. furthemore it could be slowed down a lot working with elevetor and throttle. I find also that tonneau are very elegant.
Posted by eagle60 | Jan 07, 2015 @ 09:37 AM | 9,257 Views
A friend of mine found on this site the plans for the F22. He made it according to the size and specs of the plans and it was flying yes, but it was not a really good flyer. I really like the design of this plane, so decided to modify the project. plans have been resized and placed in an image that could be printed with posteriza program (wich I enclose below) in 2highx3wide A4 sheets and overall specs are:
basic materials : specified on plans
motor : SK3-2122-2100kv
esc : 10A
receiver : orange 6 ch naked with 2x9gr servos
propeller : camprop 4x3
battery : nanotech 3s 460 mA 25-40c
Flying weight . between 150 and 165 gr
The whole project (battery apart) was less than 40 euro (1=1.35$)
I suggest also to reinfoce where the elevon horn are fixed (see photos)
Performance is excellent, you have only to find proper throw for the elevon. I use for normal flying 10mm for elevator and 15mm for ailerons (taken at the longest tip of the elevon) and 30mm elevator and 30 mm ailerons only for the spin figure (it really makes a creazy one). I hope somebody could enjoy this project.
posteriza setting : no text - no border - 5mm page margin

I realise today (2019,june 15th) that the motor SK3-2122-2100kv is no more available. Main features are:
2-3s, 2100kv, 7A max, 63W max, 24gr.
nowaday there are many motors ( specially drone ones ) with similar features or even better that could be used in this project.