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Jul 08, 2018, 02:58 PM
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Tuomo's Avatar
Xfoil is wrong, big flap works perfectly
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Jul 08, 2018, 03:42 PM
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Tuomo's Avatar
Wow, it was a busy day, but I got to field at about 8pm when thermals were still active and wind about 4m/s. I flew 2 hours. Last flights close to 10pm were in floating mode. In total, although short, this session gave me good idea of planes potential.

My Explorer BF (big flap) is about 1200g. Setup is exactly what Primoz recommended me: Schambeck 1025 in nose, giving 105mm CG. It was nice to have power for effortless vertical climb - that is definitively a tactical advantage. Some elevator adjust was made during 2 first flights, but I felt no need to adjust CG. Also the rates were ok from beginning. Roll rate is fast but smooth. Flaps down elevator compensation needs to be quite large.

In normal flying with neutral trailing edge BF feels balanced and very very agile. Aaro has a similar v-tail Explorer with normal flaps, and I expect it to basically equally good in active conditions, but his sis something we must compare. I was positively surprised how easy the pane is to fly. No "v-tail snap" and also rudder is effective. Ailerons control response is very effective. I must make comparisons with my x-tail Explorer, but first impression is that v-tail makes plane a little faster (makes sense).

Fun begins when wind dies and the recommended 10mm trailing edge camber is deployed Primoz was right, this thing jus floats and floats... I have flown all kinds of top quality FXJ planes, but never seen anything like this. 3.8m v-tail is also surprisingly stable in floating mode, and making large rudder turns is a joy.

Unlike some would expect floating speed was more like normal despite large camber. Slowing down to close to stall condition reduces efficiency. Turning at floating speed is very comfortable, maybe because of 10mm camber making actual stalling speed ridiculously slow. Good control at slow speeds makes floating performance feel even more spectacular.

If there is some truth in XFoil-theory, it must be the more moderate flap settings. I tried various 3-5mm camber settings, but they did not give me the wow-effect. Must study that later...

As mentioned, the big flap Explorer felt quite slippery for the wing loading, partly helped by v-tail. I have the advice to use very little reflex, just 1-2mm, but that I must try in stronger winds. Anyway, I am sure that this plane works well as an all-rounder, skipping the most heavy wind days. Maybe because of my F3J background I feel the light F5J planes structurally very fragile in strong winds.

Breaks are as effective as one would expect them to be. I have large 20g flap servos, and I found vertical dive with flaps down totally practical. Anyway, maybe not do that down to the deck from 800 meters... In landing mode plane is directionally as stable as one can expect a 1200g plane to be. It is important to keep speed and not to slow down too much. No matter how what the plane is, one cannot beat physics - consistent landings are impossible if one does not carry some kinetic energy all through the final approach.

To sum it up, I am a very happy man! Highly recommended.
Last edited by Tuomo; Jul 08, 2018 at 03:49 PM.
Jul 08, 2018, 07:38 PM
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Wait for the BF Vixen soon ;-)
Jul 08, 2018, 09:15 PM
Registered User
Does this wing make my flaps look big.
Jul 09, 2018, 02:24 PM
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dapan's Avatar
Thread OP
Quote:
Originally Posted by tuomo
xfoil is wrong, big flap works perfectly
Cases are the "source" of all evil.
Jul 09, 2018, 10:51 PM
E sailplane thermal hack
Quote:
Originally Posted by Keith Kindrick
Wait for the BF Vixen soon ;-)
Don't all Vixens have " BIG" Flaps? ;-)
Jul 10, 2018, 10:08 AM
Registered User
You will have to wait and see what the new version holds. Doesn't that kill you?
Jul 10, 2018, 10:25 AM
E sailplane thermal hack
Quote:
Originally Posted by Keith Kindrick
You will have to wait and see what the new version holds. Doesn't that kill you?
Yes it does ;-)
Jul 10, 2018, 01:33 PM
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dapan's Avatar
Thread OP
Just return from the field..
Windy day with 7-8m/sec wind speed.
My 4 meter Explorer with big flaps weight 1320grams make easy 10 minutes flights without ballast from 140-160 meters
Speed (3mm ) working great at this conditions The most important is that with speed or thermal ( big 10mm or small 3mm) don't need to trim elevator
Last edited by dapan; Jul 10, 2018 at 02:43 PM.
Jul 22, 2018, 03:56 PM
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dapan's Avatar
Thread OP
http://www.nanmodels.com/models/explorerbf.html

Official NAN models web page
Last edited by dapan; Jul 22, 2018 at 04:24 PM.
Jul 24, 2018, 12:39 PM
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Probebly i'm going to order a Xplorer next month. Never fly an Xplorer, but can you recommend the big flap version??
Jul 25, 2018, 01:05 AM
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Tuomo's Avatar
Quote:
Originally Posted by Adrie1966
Probebly i'm going to order a Xplorer next month. Never fly an Xplorer, but can you recommend the big flap version??
BF 3.8m v-tail.

The new v-tail fuse is also a huge improvement over the old one. Very snappy handling, yet stable when you need stability.
Jul 25, 2018, 02:07 PM
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dapan's Avatar
Thread OP
Quote:
Originally Posted by Tuomo
BF 3.8m v-tail.

The new v-tail fuse is also a huge improvement over the old one. Very snappy handling, yet stable when you need stability.

Longer fuselage improve the Explorer flying characteristics. This new loger fuselage, is good for 3.8m and 4m ( still flying my 3.5m with old shorter one, no time to check this yet and probably I will do, after EC)
Jul 28, 2018, 11:52 AM
Registered User
My Explorer BF is ordered. Any video's yet??

Where can i find the throws and correct CG point for the BF crosstail version??
Last edited by Adrie1966; Jul 28, 2018 at 12:18 PM.
Jul 29, 2018, 03:39 AM
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dapan's Avatar
Thread OP
Quote:
Originally Posted by Adrie1966
My Explorer BF is ordered. Any video's yet??

Where can i find the throws and correct CG point for the BF crosstail version??
Don't worry my friend! You will have control throws, CG point, when you will receive the plane!


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