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SF47 large depron glider

Started by kobac, June 04, 2011, 07:53:42 am

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kobac

Project cheapest big glider of the fishing rods and depron

Yoyo

Quote from: Kobac on June 04, 2011, 07:53:42 am
Project cheapest big glider of the fishing rods and depron


Presumably it's a floater?

I guess it needs the fan on the front as the gentlest way to get it up there - winch or slope might be too much for it? Or is it stronger than that?

Looks like a nicely done project though.
Doing what you like is Freedom
Liking what you do is Happiness

kobac

It was electric glider.
The project is successfully finished.

Take-off weight of 2363g
Wing area 113dm2

Static thrust 2600g is as much of the weight of the model, then no problem would have to stand in Hovering.

The engine is: TDO W35E2 KV900
[attachimg=1]
The data I copied from some site I forgot that.
• Type: Brushless
• Dimensions: Ø 35 x 54mm
• Diamètre Axe: Ø 5mm
• Poids: 177g
• Batteries: NiMh 8 à 18 ou à 3S 5S LiPo
• KV: 900V/trs
• Puissance: 650 W
• Internal Résistance: 43mohm
• Courant en pointe: 45A pendant 60 secondes
• Rendement:> 86%
• Tension d'utilization: 9-19V
• IO: 2.1 A (10V)
Hélices recommandées: 3S Lipo NiMH ou 10 14x7E APC - 4S LiPo ou 12 Nimh 12x7 - 5S LiPo NiMh ou 16 11x5.5E

Propeller is CamCarbon Aeronaut 15x6
Controller: Turnigy Plush 60amp Speed ​​Controller
Battery: Turnigy 2200mAh 3S 35C Lipo Pack
Spinning the maximum 6600 rpm.

kobac


kobac

Too bad, no one is interested glider 5m large, made out of € 50 material  + setup.

http://www.rcline.tv/video/4069/sf47-busevec

Yoyo

Quote from: Kobac on June 06, 2011, 22:47:40 pm
Too bad, no one is interested glider 5m large, made out of € 50 material  + setup.

http://www.rcline.tv/video/4069/sf47-busevec


I've definitely found I get hardly any replies on the Building Techniques forum, it might be worth trying asking the mods to move it to the powered gliding forum instead...

For what it's worth, I'm definitely impressed.  :af
Doing what you like is Freedom
Liking what you do is Happiness

kobac

I used only two fishing rod for the entire model.
[attach=1]
[attach=2]

The two thicker parts, 5m rod for the fuselage, following three, and the whole rod 3m for spar.
[attach=3]

Fishing rods for spar I put the foam "stirodur"
[attach=4]
[attach=5]

paul w

Goodwind Slope Soaring     blogtastic hill side adventures

cliffhanger

Interesting use of fishing rods as wing spars- on shorter wing span models we use golf club shafts.
As Feefo said- you would get more interest on the powered glider forum.

By the way- haven't I seen you in a James Bond movie?  :co

kobac

Quote from: cliffhanger on June 07, 2011, 18:35:44 pm
By the way- haven't I seen you in a James Bond movie?  :co


Look me in the comic book Alan Ford  [attachimg=1]

kobac

I told colleagues that I intend to do, faces all speeches
[attach=1]


Ready to cut
[attach=2]

cut the space between the ribs
[attach=3]

Ready for gluing the ribs and fill spar
[attach=4]

Glued ribs and rod
[attach=5]

kobac

Ready to cut the profile of the tips
[attach=1]

Hot wire cutting
[attach=2]
[attach=3]

Cut ribs of the tips
[attach=4]

Cut ribs of the centroplan
[attach=5]

Yoyo

Quote from: cliffhanger on June 07, 2011, 18:35:44 pm
As Feefo said- you would get more interest on the powered glider forum.


:'( :'( :'(

What is it about me that makes people remember things I said as being said by Feefo, or PDR, or....

:embarassed:  $%& :banghead:
Doing what you like is Freedom
Liking what you do is Happiness

kobac

June 07, 2011, 19:58:48 pm #13 Last Edit: June 07, 2011, 20:01:28 pm by Kobac
Quote from: Yoyo on June 06, 2011, 23:21:11 pm
I've definitely found I get hardly any replies on the Building Techniques forum, it might be worth trying asking the mods to move it to the powered gliding forum instead...

For what it's worth, I'm definitely impressed.  :af


I've listened to this advice,

Yoyo

Quote from: Kobac on June 07, 2011, 19:58:48 pm
I've listened to this advice, thank you.


No problem. I know what it's like to put a lot of effort into something and it not get noticed.

So... how does it compare to big commercial models? What does it fly like?
Doing what you like is Freedom
Liking what you do is Happiness

kobac

Quote from: Yoyo on June 07, 2011, 20:01:12 pm
So... how does it compare to big commercial models? What does it fly like?



It is impossible to compare, there are no models on the market size of 5m with a wing loading 20g/dm2. At least I do not know of such.

The model flies very slowly, beginners have enough time to bring the right decision. The model has great stability, forgiving pilot mistakes. The model survived negative loop, the positive loop, bell. Other acrobatic I did not try for now. This is not the F3A model.
The model is good for flying without wind. When you want to relax, no stress, no surprises.

We like such flights.
[attachimg=1]

Yoyo

Quote from: Kobac on June 07, 2011, 20:37:09 pm
The model is good for flying without wind. When you want to relax, no stress, no surprises.

We like such flights.


Definitely glider pilots...  :af
Doing what you like is Freedom
Liking what you do is Happiness

kobac

Quote from: Yoyo on June 07, 2011, 20:38:31 pm
Definitely glider pilots...  :af


Yes we are, but not fly SF47, I fly shadow on that image.
kobac sljeme 2009 09 06

jiberjaber

Regards,
Jason "clickerty, click, click, flickerty flick"

stukno

subscribed and looking forward to learning more.   :af

stu k

kobac

Only three templates for cutting foam. One of the root of the wings, one for connecting the central part of the wings and tips, and one for the end of the wings.
[attach=1]


Cross section of the central part of wing
[attach=2]


Cross section tips.
[attach=3]

Drawings for cutting template wings and tail

Motobiman

Hi Kobac

I just love these 'different' models and construction techniques. Well done indeed.

In the UK, an island country, we seldom get wind conditions light enough for such a model.

Some of the circa 3.6 mtr WS e gliders for HL/F5J competition flying have wing loadings of 20g/dm2 but to survive the launch loads and winds of around 10 or 12 mph they are much stronger and more rigid than your design.

Floating about in clam conditions is certainly addictive though...............

Keep it up.

be lucky

 

kobac

Quote from: Motobiman on June 08, 2011, 09:50:45 am
I just love these 'different' models and construction techniques. Well done indeed.
In the UK, an island country, we seldom get wind conditions light enough for such a model.


Thanks for the commends for the building.
I envy you for your gliding slope conditions.



kobac

I decided to put sticky tape around servos and paste them with polyurethane glue.
Servo Arms, I immediately configured and fixed. I have attached a clevis on them (http://www.der-schweighofer.at/en/product/36137/gabelkopf_metall_2_mm_10_stueck)
The idea is not to do openings for servos until something breaks or needs replacing. So, the only hole in the planking of wings will be holes through which I'll twist in metal push rods.

kobac

Now, we must put the ribs and spar!
That I made with 3mm depron. I used "Izoflor (http://www.arbiton.com/strony/1/y/229.php) panels are 120x50cm.
The surfaces of the panels are not equal, one is smooth and glossy and the other is matte.
Bending is possible only if the smooth side inside a mat outside, in the opposite panel breaks in place folding.
To leading edge was strong enough to matte side of depron with tape sticky tape

[attach=1]

[attach=2]

[attach=3]


Sticky tape will be very good squeeze to get well together on depron. It will become part of the prestressing leading edge.
Bending depron on the inside there is a crease, squeezing depron which creates pressure on the portion that is sealed.
I have tested so folded depron and the result is stunning. Resistant to impact has grown.

To depron could well bend and shape the ribs, I squeeze of depron where the sticky tape, with a thicker pipe. I used the pipe to prevent damage depron.

[attach=4]

The result of squeezing can be seen on the other, smooth, side of depron.
[attach=5]

kobac

Now be patient, no need to rush, if you do not have time, you're nervous, or anything that interferes with you, do not start this part of the job.
Folding is a very important part of which the strength of the wing.
Any bending took me 20 minutes to half an hour.
At the end of the guideline to look like.
[attach=1]

[attach=2]

In this position, which is similar to the profile, I left the board to rest, leave for 24 hours.

I found a site for izifor in English:
http://www.arbiton.com/strony/1/e/229.php

Yoyo

Quote from: Kobac on June 08, 2011, 14:07:57 pm
The surfaces of the panels are not equal, one is smooth and glossy and the other is matte.
Bending is possible only if the smooth side inside a mat outside, in the opposite panel breaks in place folding.


There was someone on another forum a while ago who worked at a Depron factory - he said the two sides were a result of the heated rollers it went through to make it set properly.

The smooth side has been melted and reset so is stronger, the other side is 'loose foam' so it compresses well but breaks under tension.
Doing what you like is Freedom
Liking what you do is Happiness

kobac

Quote from: Yoyo on June 08, 2011, 17:55:51 pm
There was someone on another forum a while ago who worked at a Depron factory - he said the two sides were a result of the heated rollers it went through to make it set properly.

The smooth side has been melted and reset so is stronger, the other side is 'loose foam' so it compresses well but breaks under tension.


Exactly, I tried to write. The construction wing styrofoam, glass, balsa, Oracover. The hard layer of glass is placed between the balsa and styrofoam. Just so I set depron.

kobac

Now I'm prepared for plating adhesion. I was drawn to the place setting.
[attach=1]

For gluing, I used two types of glue. Contact (Suadol) and polyurethane (Mitopur).
[attach=2]
[attach=3]

Trailing edge is ground down so that the profile work as intended. This profile is very sensitive to the trailing edge.
When the abrasive should be very careful depron that does not originate outside of the substrate on which it grind, every move depron over the edge where you grind, and there were at least leads to breakage of the trailing edge.  One such fault is visible in the picture. It is better to move two millimeters from the edge of the substrate rather than sandpaper Tear off the outside surface of depron.

In different places using different glues
[attach=4]

kobac

Trailing edges very thin and sensitive. Such are the cause of the trailing edge flutter in the model. That is why I cemented the trailing edge, and again in an unusual way.
[attach=1]
Between the plating I installed Milar foil which I bent at an angle that follows the upper panel. The picture is shown in yellow.

[attach=2]
milar foil trailing edge stiffening
[attach=3]
[attach=4]

kobac


kobac

Centroplan joiner
[attach=1]
[attach=2]

The first time I put the wing parts
[attach=3]

So it looks cut out and hanged aileron
[attach=4]
[attach=5]

kobac

June 09, 2011, 11:08:09 am #32 Last Edit: June 09, 2011, 11:24:08 am by Kobac
Now, we must connect a piece of rod to the fuselage with wings. On the Web I found several solutions but we were all be too heavy. I decided to combine milar foil vitroplast and stirodur. Milar foil I glued about half rod on the inside with foil glued I vitroplast 0.5 mm on both sides. The resulting cavity filled above the rod'm stirodur. Milar foil and vitroplast were a lot bigger than needed. When I adjust the angle of the wings drew up the shape wings and subsequently shaped bracket wings.

kobac

Fit Aluminum pipes I made a little larger in order to adjust the wing perpendicular to the body. I smeared aluminum pipe with a separator for molds, looseness in the joint filled with epoxy I + microbaloons. In it I laid pipe and I got a very lightweight and strong junction wings with fuselage.

kobac

There are many solutions for the construction of the tail. I wanted x tail. Maybe not the easiest, but I'm happy. The tail is very strong, usable in F3X, F5J.

Fuselage and tail with the other wings can become significantly faster model, suitable for windy weather.

I'll show you pictures, if anyone has questions I will answer




















































Rob590

Very nice mr. Kobac...

It looks like I've seen those pictures before somewhere...   :co

And it was nice to see you fly the SF47 in Buševac...  :af
Slow flyer, even slower builder...

kobac

Truth project I posted on several forums. If I want to be fair to the members of this forum I think I should write a real topic. I was able to publish the link, then no one would comment, discuss. For those who are actively participating here's a movie in HD.

SF47 u Ivanić Gradu.mp4

Woodstock

Exceptionally innovative work, congratulations  :)!
Chris van Schoor

kobac

I 've definitely wandered into the wrong forum.
No one is interested in "Building Techniques" or "Gliders & Gliding (powered), my Topic: "SF47 large depron glider "does not belong anywhere else.
I was hoping that was an interesting topic, but I've realized that the publication on your forum is a waste of time. :'(

Farewell

enginetorque

Shame  - some of us DO build on here and I reckon it's a stunning bit of 'proper' aeromodelling - nice job  :af