lefishray of foam. - RC Groups
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Nov 30, 2017, 05:37 PM
VVVLADN SKY
Discussion

lefishray of foam.


I decided to make a plane out of foam to learn how to fly on the slopes. I chose LEFISHRAY and made it from foam. The design was strong. Longeron is strengthened with bamboo. The wingspan is 1500mm, weight 700. But with a wind of 4-5m / s poorly gaining altitude. It seems to me that the wing is too thick and the profile needs another .... I want to remake to KFM! Just do not know which KFM to choose ..
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Nov 30, 2017, 09:27 PM
Registered User
Ward Hagaman's Avatar
It looks nice! However, personally I doubt that any KFM airfoil would be an improvement though...the ones I've seen were super draggy. What kind of slope have you tried it on?
Dec 01, 2017, 02:51 AM
VVVLADN SKY
Thanks for attention to my problem! In the vicinity there are no good slopes, so I want to learn to fly on the beach dunes, but they are not big either! Can I make another glider much lighter than this with the KFM wing?
Dec 01, 2017, 03:33 AM
VVVLADN SKY
Lefishray test (0 min 21 sec)
Dec 01, 2017, 04:11 AM
VVVLADN SKY
lefishray (0 min 13 sec)
Dec 01, 2017, 08:44 PM
It's time for me to fly
JimZinVT's Avatar
It looks like it glides well Vlad; it should work on the slope too. A steeper slope will help. It doesn't have to be big....My Fishray flies well on a 10foot (3m) dune in 15 - 20 mph (7 - 9 m/s). Steeper and a little more wind and she should be flying

Of course bigger is better, but we use what we've got!

Jim
Dec 01, 2017, 09:28 PM
Slope-a-Dope
Steve 0's Avatar
Quote:
Originally Posted by VVVLADN SKY
Thanks for attention to my problem! In the vicinity there are no good slopes, so I want to learn to fly on the beach dunes, but they are not big either! Can I make another glider much lighter than this with the KFM wing?
There is the Flytrap. It is a chevron wing design using the KFM foil. Can be built very light for small slopes, dunes , etc with light lift. I don't have the link but a "flytrap" search will find it.

I have built one. They are very quick and easy to build.
Latest blog entry: First PSS Warbird effort
Dec 02, 2017, 03:36 AM
VVVLADN SKY
Quote:
Originally Posted by JimZinVT
It looks like it glides well Vlad; it should work on the slope too. A steeper slope will help. It doesn't have to be big....My Fishray flies well on a 10foot (3m) dune in 15 - 20 mph (7 - 9 m/s). Steeper and a little more wind and she should be flying

Of course bigger is better, but we use what we've got!

Jim
very good!!! What is the weight of your fishray?
Dec 02, 2017, 03:39 AM
VVVLADN SKY
Quote:
Originally Posted by Steve 0
There is the Flytrap. It is a chevron wing design using the KFM foil. Can be built very light for small slopes, dunes , etc with light lift. I don't have the link but a "flytrap" search will find it.

I have built one. They are very quick and easy to build.
Thanks for the information, and you have a photo of the gliders that you built?
Dec 02, 2017, 10:20 AM
It's time for me to fly
JimZinVT's Avatar
Quote:
Originally Posted by VVVLADN SKY
very good!!! What is the weight of your fishray?
Mine is 20oz (570g). Your's is a little heavier, but with good (more vertical) lift it should work. On a flatter slope you get pushed back more than you get pushed up, so it's hard to stay just in front of the lip where the best lift is.
Dec 02, 2017, 10:26 AM
VVVLADN SKY
Quote:
Originally Posted by JimZinVT
Mine is 20oz (570g). Your's is a little heavier, but with good (more vertical) lift it should work. On a flatter slope you get pushed back more than you get pushed up, so it's hard to stay just in front of the lip where the best lift is.
I understand you, you need to look for a steeper slope. Such slopes are there, but too close to the sea and this leaves no room for error. my quality of management is too low I'm still learning ...
Dec 02, 2017, 10:53 AM
It's time for me to fly
JimZinVT's Avatar
Yes, I know what you mean. I still have the same fears, but I'm beginning to trust that I can probably fly out of most errors, if I don't panic
Dec 02, 2017, 11:06 AM
VVVLADN SKY
Quote:
Originally Posted by JimZinVT
Yes, I know what you mean. I still have the same fears, but I'm beginning to trust that I can probably fly out of most errors, if I don't panic
thanks for the support! more wind and less panic !!! you need to fly more and gain experience, but this requires a glider for training (perhaps easier).
Dec 02, 2017, 11:13 AM
Firecracker!
BillO's Avatar
The best way to learn in the beginning is to use a flight simulator on a PC. There are many to choose from including two free open source ones (Picasim and SSS). It will save you many hours of frustration.
Last edited by BillO; Dec 02, 2017 at 11:18 AM.
Dec 02, 2017, 11:47 AM
VVVLADN SKY
Quote:
Originally Posted by BillO
The best way to learn in the beginning is to use a flight simulator on a PC. There are many to choose from including two free open source ones (Picasim and SSS). It will save you many hours of frustration.
yes it's true, I regularly train in Picasim and thanks to him I have not learned much. This yellow glider (wingspan 2000mm, weight 1200g.) I built a year ago and started flying when I was living in Ukraine. But I could not bring to Israel and built lefishray.
Slope soaring rc glider depron 2000mm (1 min 46 sec)


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