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Homemade Slope Soarer - Build log

Old 09-29-2018, 03:35 PM
  #26  
aaindthu
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Today I learnt myself One big lesson

It is a BAD idea to put symmetric airfoil in a glider especially

when there is no slope for soaring..

My glider was working fine, it turned left, right, pitching up and down but..
it never climbed. I mean it came down too fast.

I think it was because of the symmetrical airfoil that i used or it could also be because there was no significant slope from where I tried.

But I am going to try again with a camber airfoil next week with the same fuselage.

So, the bottom line is that my glider design is a flop.

Last edited by aaindthu; 09-29-2018 at 11:24 PM.
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Old 09-30-2018, 12:44 AM
  #27  
Panther
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Don't get disheartened. Try a lifting airfoil like a Clarke Y (from memory) You do need a reasonable breeze and a fairly high slope for slope soaring.
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Old 09-30-2018, 04:24 AM
  #28  
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Originally Posted by aaindthu View Post
.........So, the bottom line is that my glider design is a flop.

If you learned something, the project wasn't a flop, it was a learning experience.......
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Old 09-30-2018, 06:17 AM
  #29  
aaindthu
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Thank you for your kind words.
They are encouraging.
I hope the glider flies better next time with a lifting airfoil like Clark-Y.
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Old 09-30-2018, 11:11 PM
  #30  
quorneng
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aaindthu
There is nothing wrong with Clark Y particularly at small sizes however in a glider where you are trying for good performance make sure it is a accurate Clark Y section and the surface is as smooth as possible even if it requires a small weight increase to achieve it.

The "glide" performance benefit of an accurate profile Clark Y profile is quite significant. Although a poorly shaped Clark Y will create virtually the same lift it will require a bit more power to do so which in a glider you just don't have!

As Brner says building and flying your own design plane is never a waste as long as you work out what features were below you expectations and what to do that improves them.
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Old 10-01-2018, 05:49 AM
  #31  
aaindthu
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Originally Posted by quorneng View Post
aaindthu
There is nothing wrong with Clark Y particularly at small sizes however in a glider where you are trying for good performance make sure it is a accurate Clark Y section and the surface is as smooth as possible even if it requires a small weight increase to achieve it.

The "glide" performance benefit of an accurate profile Clark Y profile is quite significant. Although a poorly shaped Clark Y will create virtually the same lift it will require a bit more power to do so which in a glider you just don't have!
Quorneng,

I am already finished making the new wing and even did some glide-test.
I launched it (without Transmitter control) aiming at a bush several times to test its glide angle.
One time, as the glider was gliding and was about to hit the bush and suddenly the wind started to blow and carried the glider to some height and the glider could not fight the wind and turned itself along the wind direction and landed some distance away from the bush.
I wish I only had the Transmitter in my hand to control and I was left watching it.

I am happy with the new wing. The breeze was plenty more at the beach.

So I expect this glider to climb into the winds without any problem.
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Old 10-02-2018, 02:05 AM
  #32  
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This is how my modified glider looks now.

The glider
Name:  001.JPG
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The airfoil
Name:  002.JPG
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Old 10-02-2018, 02:30 AM
  #33  
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Should be good

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Old 10-02-2018, 07:02 AM
  #34  
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Looking Good make yourself a power pod, Strap it on the main wing, use either gas or e power to get the plane in the air with, I learned to fly with a 2 meter Glider with a power pod and a 049 Cox engine with a 6x4 prop, it got the glider up there then it ran out of gas then i would catch thermals and normally fly for about 1 hour. set the CG to 25% back from the front of the wing to start with, a nose heavy plane is Best for a beginner, because the nose will drop before you stall the plane, I used to fly 1/2 planes with a Fox 15 engine in them, What a blast, they never stalled in flight, it was a ACE Whizard, its was so much fun with a 7x6 prop it was fast too








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Old 10-02-2018, 07:04 AM
  #35  
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Whizard 1/2 A Plane and i used a fox 15 engine in it, What fun :0

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Old 10-02-2018, 07:07 AM
  #36  
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aaindthu since you like to build, here are some of my scratch built Planes, Have fun, Chellie.


https://wattflyer.com/forums/showthread.php?t=55444
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Old 10-02-2018, 08:06 AM
  #37  
solentlife
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I learnt to fly Slope before power and I really miss it as Latvia has no decent hills to create good flight location.

Ridge soaring is actually not quite the same as Slope ... because Ridge soaring is limited in lift area and requires finer control by the pilot. Ridge soaring is often with much smaller rise of ground to create the upgoing airflow needed for the soaring.

Beach soaring where often you have a cliff or steep ground rise at back of beach provides serious lift but has a factor that catches many out ... the rise being near vertical and usually with a sharp top change to level creates a serious turbulent area just a few feet back from that edge ... so you MUST fly ahead of the cliff ... but the distance ahead is also limited .. Its a strong lift environment but generally a narrow band along the front of the cliff or ridge. It also does not extend to significant altitude due again to turbulence.

But Slope soaring as the name suggests is actually where you have a slop and is best with a rounded top that eases into level ground. This type of location provides a wider and higher lift area but unless wind is strong - weaker than the sharp cliff or ridge. It is not unusual for slopers to fly BELOW hill top line ... and actually significant height above it. It also lends itself to less abrupt lift loss and hard landings !

OP's observation of lift when the wind picked up is typical reaction of the model when its angle of attack of wing is then subjected to an increased airflow .. it rises ... but it will then quickly stall or yaw round as he observed. Not having the TX meant he could not pitch the nose down to keep her straight and onward.

As to symmetrical airfoil .... only if you want to aerobat really ... then you need to fly faster ... in UK - I flew various ..

SS Ridge Recruit - Clark Y
RC Mendip - Clark Y
Phase 4 - Compromise of sort of Y and semi symmet .. not really sure what it was but not one or other !! Good intro to mild aerobatics
Phase 6 - Semi Symmet for competition where endurance was needed but also speed
Phase 6 / Centi-Phase - full symmet for speed and aerobatics.

plus a couple of Thermal jobs ...

Here's a photo from the early 1980's of a part of my hangar .. you see the Phase 6 full symmet and the Phoenix Thermal job at the back ...




I love sloping and really do miss it. We have relatively low cliff edges to our beaches in Latvia .. about 10 - 15m height - but they are sheer and the turbulence is strong. Maybe I will have a go one day ... evening shots with setting sun are fabulous over water with sloper silhouetted ....

Nigel
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Old 10-02-2018, 11:49 AM
  #38  
quorneng
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aaindthu
That looks really nice.
I am sure it will fly well but it I suspect it would make a rather better power plane or as Chellie suggests a power assisted glider.

I have no hill or even gentle slopes where I fly so all my planes are powered but in the right weather conditions there are thermals. These 'columns' of rising air are plenty strong enough to lift even a simple plane to a great height but thermals are basically 'invisible' so not that easy to find!
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Old 10-02-2018, 01:33 PM
  #39  
aaindthu
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I know now that it requires slope for slope soaring.
I learnt it the hard way.

I flew this glider second time and it was not much different from the first one.

There was a small slope though. I did launch my glider in such a way that it flies above the slope. Just as it passed above the slope, it lifted slightly up.

Then I realized about the slope that you all mentioned. I simple don't have sufficient slope for soaring.

So, I am giving up on building gliders - for now.

Thank you all for your support. I will return with some other project soon
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