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        Cool Lun/Spasatel Ekranoplan build *IT FLIES! with photo's!

#1 hoverman Dec 17, 2009 12:04 PM

Lun/Spasatel Ekranoplan build *IT FLIES! with photo's!
 
Hey guy's,

I just had to show you what I've been doing in my garage for the last two days! I started with a threeview drawing of the Lun ekranoplan and simplified it to the Spasatel, then got rid of all the details, till it resembled what I wanted to shape from Solid Bluecore foam?(here they call it TEMPEX or Styrodur)

Ahwell it isn't much yet but it looks quite cool.

This is the plan..threeview..drawing whatever :p

http://i218.photobucket.com/albums/c...ipilot/lun.jpg

And this is it so far, still have to sand down the whole tail fin and tail dome, need to make wingtipfloats and ofcourse the wings need to be attached...and it needs controll surfaces and a propulsion, and ofcourse it needs paint;)

http://i218.photobucket.com/albums/c...DSC_0010-1.jpg
http://i218.photobucket.com/albums/c...DSC_0013-1.jpg
http://i218.photobucket.com/albums/c...DSC_0016-1.jpg

Marijn

#2 hoverman Dec 17, 2009 12:19 PM

It is about 1.2 meters in length, because I didn't want the wing chord to get too small.

As for the main wing, the profile is of a fully symmetrical type this time, the real Lun didn't have a very strongly cambered wing either and I wanted to try these profiles in ground effect for a long time.

I'm planning to use a simple gyro on the elevator, and it's COG will be between 50% and 75% of the wing chord(the stabiliser is positively loaded, not like an airplane stabiliser)

As for the propulsion, it will get a single outrunner on the tail, just to keep the costs low.

Marijn

#3 HoverTim Dec 17, 2009 01:17 PM

ekranoplAN
 
That looks good i will be nice to see it going

#4 hover dude Dec 19, 2009 12:53 PM

Nice work! Any specifics on the power system?

#5 hoverman Dec 20, 2009 03:52 AM

Well this is one of those builds like... hey lets build a model dunno how bit it will be...

I am planning on using a 1000KV outrunner from himodel and power it by either 3 or 4 cells. I've got a 3700mAh 4S flightpower lying around which should do the job. As for the location, I think i'll mount the engine forward of the Dome on top of the tail fin.

As for the progress of the model, I've made the sponsons and started sanding down the tail fin, however, at the moment we have got a lot of snow coming down outside and I don't feel like standing out there, sanding this thing, with my fingers freezing of;)

Marijn

#6 ftwtf Dec 20, 2009 02:40 PM

Hi

I just started building the A-90 Orlyonok.
I ve been having troubles with the correct lengths because i dont have any plans.
Its gonna be about 1,65 meter long.
I will make the shape out of styrofoam and to make it strong i will put 2 big wooden poles in the middle. At last i m going to going over it with fiberglass
Im gonna use a nitro engine as propulsion

#7 hoverman Dec 20, 2009 02:50 PM

Heyman, this is what my Orlyonok looked like, I made it from Styrodur

http://i218.photobucket.com/albums/c...t/PICT0165.jpg

I covered it with glassfibre, than had a lot of sanding and some painting to do
http://i218.photobucket.com/albums/c...t/DSC_0736.jpg

Ow and uhm...it ended in the trashcan achum..
It was way to heavy and i made some mistakes so I started over with the Lun

Marijn

#8 ftwtf Dec 20, 2009 11:52 PM

Did it get so heavy because of the glassfibre?
should i not put glassfibre on it ???

#9 hoverman Dec 21, 2009 01:21 AM

well it depends of course on how you glass it. This was the first model i glassed and I used way too thick glass. I think glassing is fine but nomatter what you do it will still turn out to be quite heavy.

I won't glass the Lun, just going to paint it till it's smooth, The foam should be more than strong enough for normal use.

Marijn

#10 hoverman Apr 02, 2010 10:55 AM

So, I thought it was time for an update!

Progress is very slow, cause I am also building VTOL's and they tend to draw away a lot of building time;)

So after completely assembling the model and a lot of sanding, it really started looking like the Spasatel. I then covered it with some white base paint(acryl). After some layers with carefull sanding in between it looked like this:
http://i218.photobucket.com/albums/c...t/DSCN2319.jpg
Marijn

#11 hoverman Apr 02, 2010 11:45 AM

And..some more updates, now in some early gray, I also started cutting out the battery hatch and the rudder..
http://i218.photobucket.com/albums/c...t/DSCN2326.jpg
http://i218.photobucket.com/albums/c...t/DSCN2328.jpg
http://i218.photobucket.com/albums/c...t/DSCN2330.jpg
http://i218.photobucket.com/albums/c...t/DSCN2332.jpg
http://i218.photobucket.com/albums/c...t/DSCN2333.jpg

Marijn

#12 hoverman Apr 11, 2010 12:05 PM

And some more updates, I made a hatch, an started on the controlls. The ailerons are hinged on the top side of the wing, because the tail will give positive lift(not as on an airplane)

http://i218.photobucket.com/albums/c...t/DSCN2424.jpg
http://i218.photobucket.com/albums/c...t/DSCN2423.jpg
http://i218.photobucket.com/albums/c...t/DSCN2415.jpg
http://i218.photobucket.com/albums/c...t/DSCN2414.jpg
http://i218.photobucket.com/albums/c...t/DSCN2422.jpg
http://i218.photobucket.com/albums/c...t/DSCN2419.jpg

Greetz;)

Marijn

#13 metroidrc May 27, 2010 10:36 PM

wow that's impressive. be sure to get video!

#14 hoverman Jun 01, 2010 04:45 AM

Hey Metroid, Allready a while ago I finished the Spasatel for the first test runs. First I added the Brushless:
http://i218.photobucket.com/albums/c...t/DSCN2429.jpg
http://i218.photobucket.com/albums/c...t/DSCN2427.jpg

I placed two rate Gyro's, both lying on it's side, angled 90 degrees to each other:
http://i218.photobucket.com/albums/c...t/DSCN2446.jpg
(kinda hard to see:P)
By placing them like this they are both stabilising roll & pitch, both beeing connected to one of the elevons on the tail!

Servo's...
http://i218.photobucket.com/albums/c...t/DSCN2444.jpg

Then..it was ready for the first tests! They quickly revealed a design flaw, When the craft starts aquaplaning, the front Hull step also touches the water, which means the craft has two water contact points during planing, allthough the CG is located very near to the rear hull step.
Alltogether this means that as soon as the model starts aquaplaning, it is directionally unstable and does it's best to go anything but straight forward!;)

I changed this by adding a lager Hull step which also was located nearer to the CG, to reduce the nosedown attitude during aquaplaning, Plus by adding a small Aluminium fin below the tail:

http://i218.photobucket.com/albums/c...t/DSCN2435.jpg
http://i218.photobucket.com/albums/c...t/DSCN2440.jpg
http://i218.photobucket.com/albums/c...t/DSCN2441.jpg

The final model:
http://i218.photobucket.com/albums/c...t/DSCN2447.jpg

And...the next test run was higly succesfull. The model starts aquaplaning after a few meters and quickly accelerates. Without rudder input it keeps track and after 50-100 meters it starts to completely unstick from the water, no instability issues sofar!:D

After the second high speed pass, during "landing", the model started to slip sideways. I tried to prevent this by using opposite rudder input, but the model tripped over it's left sponson(float) and rolled over completely, ripping of its rear stabiliser.

Now I actually did pull of my clothes and jumped into the water, but it was kinda "too late".

Back on the dry I found the brushless outrunner beeing completely stuck, I couldn't turn it any way, probably some loose magnets! I then opened the electronics hatch and found that the broken Brushless motor had shorted out my ESC, which had burned out.

The Lipo was fine, the ESC and Brushless are trash!

The model is now standing in my room, at the moment I don't have the financial capabilities and the motivation to continue testing;)

Greets,

Marijn van de Ruit

#15 RdsG Jun 01, 2010 03:58 PM

Nice one!

I hope it will fly again.


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