Micro DLG Yasu Airfoil test on Balsa Wood - WattFlyer RC Electric Flight Forums - Discuss radio control eflight

Hi-Performance and Sailplanes RC hotliners, electric pylon racers, F5B, F5D, sailplanes and gliders

Micro DLG Yasu Airfoil test on Balsa Wood

Old 03-26-2013, 05:57 AM
  #1  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default Micro DLG Yasu Airfoil test on Balsa Wood

Here is my first attempt to sand a Yasu airfoil on a micro 11" DLG wing

Last edited by littlephoenix; 07-06-2019 at 09:17 PM.
littlephoenix is offline  
Old 03-26-2013, 07:11 AM
  #2  
JetPlaneFlyer
Super Contributor
 
JetPlaneFlyer's Avatar
 
Join Date: Mar 2009
Location: Aberdeen, Scotland
Posts: 6,121
Default

Looks like a nice carving job... but what's a 'Yasu' airfoil?
JetPlaneFlyer is offline  
Old 03-26-2013, 09:23 PM
  #3  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

Yasu is a great Japanese DLG builder, you can google him, i believe this is his twist on micro DLG wing foils.
littlephoenix is offline  
Old 03-26-2013, 09:46 PM
  #4  
JetPlaneFlyer
Super Contributor
 
JetPlaneFlyer's Avatar
 
Join Date: Mar 2009
Location: Aberdeen, Scotland
Posts: 6,121
Default

Interesting. I winder how the performance compares with established airfoils such as the Drela AG-14.. that's the foil used on the tip of the Supergee and also on the 1M Elf micro DLG.

The Drela foil looks a little thinner and less cambered so I'd guess might launch higher but maybe not float as well.
Attached Thumbnails Click image for larger version

Name:	ScreenHunter_01 Mar. 26 20.44.jpg
Views:	5156
Size:	70.7 KB
ID:	167406  
JetPlaneFlyer is offline  
Old 03-27-2013, 06:16 AM
  #5  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

I have used Drela's AG-14 many times, my guess is the smaller the glider, the more the camber, you might be correct, the launch should be higher on the AG14 for being flatter, i will test this theory soon but Yas's micor DLG's seem to tell the full story

Last edited by littlephoenix; 07-06-2019 at 09:19 PM.
littlephoenix is offline  
Old 03-27-2013, 08:42 AM
  #6  
JetPlaneFlyer
Super Contributor
 
JetPlaneFlyer's Avatar
 
Join Date: Mar 2009
Location: Aberdeen, Scotland
Posts: 6,121
Default

Well actually, theory would tend to point the opposite way. At the lower Re numbers small gliders fly at conventional theory tells is to use less camber (and less thickness). Reason being that slow moving air in low Re regime doesnt follow a curved surface as well as faster moving air, so curvature needs to be reduced to avoid separation. Hence my curiosity on the Yasu airfoil
JetPlaneFlyer is offline  
Old 03-27-2013, 08:05 PM
  #7  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

although that does make sense, these guys in Japan seem to say otherwise as they are the first in their class in the 600MM DLG's and from trial and error, they seem to get 80 second flights out of these micro DLG's.
only way to find out is by doing it whcih is why im here, i will soon find out and let you know
littlephoenix is offline  
Old 03-27-2013, 08:14 PM
  #8  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

this is what he says BTY

"The high aspect ratio wing design of this plane is based on my friend Mr. Junji Ishii's design.
Ishii is a specialist of aircraft design.
He calculated the performance and found that, the higher aspect ratio design is superior on sink rate at slow flight.
I saw his plane flies very well and soon changed my mind to follow him.
Wing loading of my 26g plane is higher than that of full sized DLG, but the sink rate is superior. It was a big surprise.
He said that wider chord plane is superior in higher speed range."
littlephoenix is offline  
Old 03-27-2013, 09:09 PM
  #9  
JetPlaneFlyer
Super Contributor
 
JetPlaneFlyer's Avatar
 
Join Date: Mar 2009
Location: Aberdeen, Scotland
Posts: 6,121
Default

This all sounds totally opposite to conventional wisdom. The 'rule book' says at smaller sizes you go to lower aspect ratio because the wider chord gives higher Re number. Very low re numbers are disastrous for lift/dag performance so best avoided. You just have to accept the induced drag trade off vs. high aspect ratio.
I've seen Ishii's designs fly on video and you cant argue with his results, his gliders are spectacular. But this micro size model seems much narrower chord than his larger gliders so the same approach may not work.

Is 80 seconds in 'dead' air? (indoors maybe?) If so that's mighty impressive. If I'm throwing well I get 80s out of my 1M Elf DLG
JetPlaneFlyer is offline  
Old 03-27-2013, 09:21 PM
  #10  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

i agree, but again these guys are flying 22" wingspan gliders not 1M
here is the full thread http://www.rcgroups.com/forums/showthread.php?t=1492035
again this is new to me, that is why im curious and building it for a test

the micro DLG's whcih i build and sell use the Drela AG03, this will be a good test
littlephoenix is offline  
Old 03-27-2013, 10:10 PM
  #11  
JetPlaneFlyer
Super Contributor
 
JetPlaneFlyer's Avatar
 
Join Date: Mar 2009
Location: Aberdeen, Scotland
Posts: 6,121
Default

Originally Posted by littlephoenix View Post
i agree, but again these guys are flying 22" wingspan gliders not 1M
Yep, which was why I said it was mighty impressive.

Just watched the video, amazing!.. If I was to be real sceptical I guess it would be nice to see a few flights back to back to see what the average is, but either way the performance is outstanding for such a tiny glider.

PS.. did you use any sanding guides or rib templates to do the wing sanding, or was it all by eye?
JetPlaneFlyer is offline  
Old 03-28-2013, 08:59 PM
  #12  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

i used Yasu's sketch for reference, ive been sanding foam wings for a long time now and never thought i would be able to sand balsa wings, especially the trailing edge, sure one wing is easy but duplicating the same patten on the other wing,, i used reference lines and it seemed to work great, see attached sketch and the other is my finished wing, need to apply lacquer and all done.
Attached Thumbnails Click image for larger version

Name:	sand.jpg
Views:	3426
Size:	89.6 KB
ID:	167452  

Last edited by littlephoenix; 07-06-2019 at 09:19 PM.
littlephoenix is offline  
Old 03-29-2013, 12:42 AM
  #13  
fhhuber
Super Contributor
 
fhhuber's Avatar
 
Join Date: Mar 2013
Posts: 4,786
Default

under-chamber is interesting in its effects.

A small amount adds significant lift and little drag.

More keeps adding lift but drag added gets significant fast. You can create HUGE lift with a 30% underchamber but you better have power... its like full flaps and more on a full scale aircraft. You almost push all the air the airfoil works on straight down.
Slow and heavy lift go for huge underchamber.

*****

To be able to duplicate the airfoil you "tacky glue" sandpaper to the one you made... use that as a sanding block to sand a block to the inverse shape. Put sandpaper on that. You can now repeat the shape forever.

************

Be VERY careful lacquering balsa. it can warp very badly. Light coat... clamp in a form for that thin airfoil... then do the other side. And still you'll have to be watching and correcting warps as you go.
fhhuber is offline  
Old 04-02-2013, 09:44 PM
  #14  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

ive tried using a template sandblock but it doesnt really work, i find just using a block to sand works for me, i ended up not using lacquer but rather covering the wing with ultra coat, some pics below

these Japanese builders know what they are doing, as their 600mm DLGs have broken records, so that is why i was shocked as well for the super underchamber, only way to find the truth is trial and error, which is where im at, just need to slap on electronics and see how she glides.
this is a 21" wingspan

Last edited by littlephoenix; 07-06-2019 at 09:18 PM.
littlephoenix is offline  
Old 04-02-2013, 10:14 PM
  #15  
JetPlaneFlyer
Super Contributor
 
JetPlaneFlyer's Avatar
 
Join Date: Mar 2009
Location: Aberdeen, Scotland
Posts: 6,121
Default

Is it freeflight or RC?

weight?

Good luck with the maiden. I'm almost tempted to crack open my box of 4lb contest balsa. One feature I noted on the Japanese guys gliders is the extra long tail boom, longer even than the long booms fitted to the typical DLG... Possibly an important feature in terms of launch height?
JetPlaneFlyer is offline  
Old 04-02-2013, 10:22 PM
  #16  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

this will be RC, so far all up weight is around 35grams, using 1.7gram servos, micro receiver and 130mah 1s lipo, and you are correct, they use a longer boom and smaller tail feathers
where do you buy your contest balsa from?
this is a fun project, you should give a go, i will post maiden flight video soon
littlephoenix is offline  
Old 04-02-2013, 11:32 PM
  #17  
riverrat
circa: 1946
 
riverrat's Avatar
 
Join Date: Jul 2008
Location: Eulonia, Ga.
Posts: 629
Default

Littlephoenix


Good luck on the maiden.

Looking fwd. to the video.

Regards
Jimmy
riverrat is offline  
Old 04-03-2013, 12:42 AM
  #18  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

thank you Jimmy

Last edited by littlephoenix; 07-06-2019 at 09:18 PM.
littlephoenix is offline  
Old 05-16-2013, 08:05 AM
  #19  
littlephoenix
Member
Thread Starter
 
littlephoenix's Avatar
 
Join Date: Jan 2008
Posts: 104
Default

here is the video of the final build, she flies great in windy conditions, and i only assume she will stay skyhigh under updraft winds, but the longest flight i had was around 43 seconds, not to bad, will fiddle with different airfoils and see the difference.

Last edited by littlephoenix; 07-06-2019 at 09:18 PM.
littlephoenix is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
drummaker
Scratch and Kit Built Aircraft
62
11-23-2013 10:31 PM
Merritt
General RC items For Sale and WTB
0
02-17-2013 11:53 PM
littlephoenix
Hi-Performance and Sailplanes
1
10-23-2012 09:20 AM
Joe 1320
Electric Ducted Fan Jets
13
02-02-2012 01:15 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Quick Reply: Micro DLG Yasu Airfoil test on Balsa Wood


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

Page generated in 0.08583 seconds with 16 queries