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Yasu's blog
Posted by Yasu | Feb 18, 2012 @ 08:04 AM | 11,517 Views
Servos and receiver are buried in the wing.
Finished just now. Not yet tested.
HK servos seems good in neutral.

wing max thickness: 6mm
profile: my latest 1202c(see my former post)
span: 585mm
length: 535mm
28grams all up weight
wingTE to tail LE: 271mm
Rx: FrSky V8R4
servo: two HK 1.7g
battery: 3.7V 138mAh Lipo
Posted by Yasu | Feb 02, 2012 @ 11:52 PM | 13,386 Views
On balsa solid wing, especially if you use very light material, the wing flutter is a serious problem.
So I am trying to create new wing profiles to fix them.

The image I attached (1202c) is one example.
You can see the thickness is well remained at rear quater.
Despite very different shape from previous profiles, it has good trial result.

The 1202c profile improves tortional stiffness significantly.
I launched one test bed at my full power in 3m/s wind and no flutter occured.
And it also improves launch height in comparison with well under-cambered profile.
Only negative point is a weight, due to its volume.
The weight is heavier by 20% to 40% than previous wings.

Both flat areas are parallel, so you can use the material surfaces directly.
Posted by Yasu | Nov 06, 2011 @ 09:06 AM | 12,747 Views
The wing is made by Mr. Mitsuru Ishii, a famous FF glider competitor.

Data:
All up weight: 83g
Rx: Frsky V8R4
Two 3.5g servos for rudder and elevator
One cell 138mAh Lipo

I'll make comparison flight with the ELF....Continue Reading
Posted by Yasu | Aug 20, 2011 @ 09:54 AM | 25,200 Views
My 600mm DLG marked 80sec. duration time in early morning test session.
Launch height is around 25m.
I think the sink rate is now superior than full sized DLGs.

600mm micro DLG time trial 80sec. (1 min 55 sec)


The overalll design is based on Mr. Junji Ishii's design.
Mr. Ishii was a chief designer of record breaking HPA Nihon University's Stork.

I'm planning to flight these planes with former F1N(indoor free glider) world record holder Mr. Mitsuru Ishii at indoor to precised record.

2011#6 is the second newest design.
26g all up weight, two 2.5g servos, sanwa rx40v, and 100mAh 1cell Lipo.

2011#7 is the newest one.
27g all up weight, same components as #6.
Posted by Yasu | Dec 13, 2010 @ 07:19 AM | 14,543 Views
My new 600mm DLG achieved 45m(147ft) launch at almost calm condition.
The height is measured at exhibition held after Japanese local DLG competition meet and by laser range finder.
(My average launch height of full size DLG(240g) is around 55m.)

Now micro DLG can compete with full sized DLG on at least launch height!

Data
span: 597mm
weight: 65g
servo: three arced D531BB digital(for flaperons and elevator)
rx: SANWA Airtronics 6ch 2.4GHz
batt.: 180mAh Hyperion 1 cell Lipo
tail boom: AVIA sport skinny-UL
surfaces: balsa solid, finished by thinned epoxy resin and talc, polished
weights of components: finished wing total 27g, tail group total 2g
angle of attachment: zero-zero at bottom surfaces to boom
Posted by Yasu | Nov 13, 2010 @ 10:22 AM | 14,572 Views
Today I competed with other micro DLG made by Shuhei Okamoto, a Japanese major competition RC sailplane flyer/builder.
We are planning to make a local racing rule of this class now.
Small sailplanes will suitable to organaize competitions for here Japan and we think launch height between competitors will compressed by downsizing to achieve more thermaling skill oriented competition.

At today's comparison flight, my plane(#2) shows its superior launch height.
It seems about twice as high as Okamoto's one.
Therefore, the result was my decisive victory with 6 sets to 0(3flight for a set).

Despite the smallest sized DLG of my product, this is the best performer.

launch movie
600mm micro DLG launch (0 min 22 sec)


comparison flight
...Continue Reading
Posted by Yasu | Nov 12, 2010 @ 10:20 AM | 15,731 Views
I have made maiden flight of my new 600mm 50g DLG today.
It was windy day, gust up to 5m/s today at Okayama Japan.

It withstood my full power launch.
Fun to fly, but I felt something sensitiveness on pitch in comparison to #2.
It penetrates well, and floats better than #2.
But total balance is seemed to be slightly inferior to #2.

flight movie
600mm micro DLG#3 flight (1 min 10 sec)


detail movie
...Continue Reading
Posted by Yasu | Nov 08, 2010 @ 09:43 AM | 16,356 Views
I just finished my new micro DLG(#3 of this year).
It features slightly enlarged wing area and more stiff tail boom.
I'll make maiden flight at this weekend

Former #2 flies very well. I think it reaches about 30 to 35m at calm.
I'll measure them with laser range finder later.

Note the c.g. is so aft like FF gliders(same as #2; 56% at root).
Despite this feature, pitch stability is so good and control is easy. Handling feels docile if you are well advanced glider pilot to keep pitch/speed well.
But once you push stick to nose down, the plane goes straight into ground.
Launch direction is also straightforward. Requires some upper swing.
Stall manner is excellent without any drop of wingtip or tendency to spin.
Make intentional spin is difficult.

Data(#3)
wingspan: 594mm
length: 555mm
all up weight: 50.2g
tail group: 2.0g
wing: 19g
total area: about 6dm^2
servos: 2*waypoint w-038cl
rx: airtronics 2.4GHz 92664
batt.: hyperion 1cell 120mAh 25c
angle of attachment: zero degree(both wing and tailplane)
control: 0.4mm stainless steel rods and 1.0/0.5mm carbon outer tubes
surfaces: all solid balsa finished with thinned(by 100% ethyl alcohol) epoxy resin(*2 times, first one with tulc)...Continue Reading
Posted by Yasu | Oct 31, 2010 @ 01:52 PM | 17,566 Views
span: 594mm(23.22″)
length: 540mm
weight: 43.7g(1.51oz.)
total wing area: about 5dm^2
aileron,elevator: 2*4g digital servos
Rx: 2.4GHz 4ch 3g micro receiver(prototype)
batt.: 100mAh 1cell LiPo

flight movie taken by my friend(Youtube)

More pics on my other blog.(only Japanese)

Pics added on my comment. Check them please.