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Old Nov 14, 2011, 03:13 PM
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Jacques.Eloff's Avatar
United Kingdom, England, Cobham
Joined Oct 2007
550 Posts
Can someone kindly tell me what the recommended CG for the Mig-15 is? I tried to maiden with the CG on the aileron servo wires at the wing root (as recommended by others in this thread) but it seemed way too far back. Came down really hard, but luckily no noticeable damage.

Jacques
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Old Nov 14, 2011, 03:50 PM
Electric flyer
fly time's Avatar
Renton, WA, US
Joined Oct 2007
1,291 Posts
Speaking of CG's....

I have a PNP T-45 from HK that I have yet to fly (waiting for an Rx). As per HK's "combo items", I also picked up a Turnigy 2S 500mAh battery. You would think that they would only recommend batteries that actually fit in this plane, but of course that is not the case when buying direct from Hong Kong

Anyways, I cut away enough of the foam to get this 36 gram battery installed, but even before installing an Rx (which will also go forward of the CG if I'm not mistaken), I am WAY nose heavy! What are you guys doing to the T-45 to get it balanced??? With some careful cutting of foam, I can push the battery back a little more, but that may not be enough
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Old Nov 14, 2011, 05:08 PM
Gravity sucks.
Australia, QLD, Toowoomba
Joined Mar 2011
563 Posts
Quote:
Originally Posted by fly time View Post
Speaking of CG's....

I have a PNP T-45 from HK that I have yet to fly (waiting for an Rx). As per HK's "combo items", I also picked up a Turnigy 2S 500mAh battery. You would think that they would only recommend batteries that actually fit in this plane, but of course that is not the case when buying direct from Hong Kong

Anyways, I cut away enough of the foam to get this 36 gram battery installed, but even before installing an Rx (which will also go forward of the CG if I'm not mistaken), I am WAY nose heavy! What are you guys doing to the T-45 to get it balanced??? With some careful cutting of foam, I can push the battery back a little more, but that may not be enough
This.... plane...(t-45)

The 500mah 2s battery that's recommended is an approximation of the 'right' battery for this aircraft. -it's too heavy and too big to fit properly. 'stable flight' can be achieved but because it's too heavy (spec AUW=95 grams, with 500mah 2s you're looking at 116grams) you'll be at full throttle the entire flight, and if you back off... it drops like a rock.

If you want to stick with 2s, then 360mah is better suited to the purpose or even 2s 300.
the point is, 2s is a bare minimum and the supplied ESC is not compatible with 3s. (it dies if you plug 3s into it)

Last night i pulled the wing off (g e n t l y), then muscled the tiny EDF out and unsoldered the ESC and replaced it with a 6amp turnigy plush ESC which does support 3s. I've got the 12amp plush on backorder from hk too (for if/when the 6amp dies). I glued the EDF back in and will try putting the rest together tonight.
According to NitroCharged, you don't need take the wing off, but i can't see him unsoldering the ESC and replacing it with the wing on?

Thrust with the 6amp plush as bare edf - 5 blade:
2s 500mah WOT: 63 grams
3s 460mah WOT: 114 grams (ESC and motor get hot)

PS - you CAN replace the ESC with the wing on IF you can get the EDF out without removing the wing, mine was glued in exceptionally securely toward the turtledeck side of the airframe... had to take the wing off to get necessary leverage.
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Last edited by m_ark; Nov 14, 2011 at 05:11 PM. Reason: added PS.
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Old Nov 14, 2011, 05:17 PM
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Angelo's Avatar
Chicago, IL
Joined Nov 1999
2,058 Posts
Maiden success!

Just got back from maidening the F-86. Bound the new orange receiver to my also new Spektrum DX6i, then spent quite a bit of time figuring out the expo and dual rates set up. After installing everything, it needed 1/4 oz. lead to get the CG at 59mm. I HATE adding dead weight to a model, especially one this small. I used one of those stick on weights, and I put it right under the nose on the intake lip. I didn't want to put it inside, since I wanted to keep the intake airflow clean. This lead to some problems later.

Ran out to the nearby empty field, checked the control operation, and realized the ailerons were backwards. Always important to make sure the surfaces aren't just moving, but in the right direction! Fixed that, throttled up, and threw it into the air. It started diving into the ground, got my hand on the sticks but still hit the ground at a shallow angle.

The nose weight caught the ground and tore the bottom of the intake lip. Arghhh! But I was able to push it back into place. Went to re-launch, but this time with 9 clicks of "up" trim.

Good launch this time, I threw it steeper, it still dove a little but I was off and away. It was very sensitive in roll, even with my "adjustments" to expo & dual rates (more on this later) but it was off and flying making circuits of the football sized field. A few clicks of down and left aileron, and I was tearing around the sky. Who said this thing barely flew on 2s? This sucker is fast! I dialed the throttle back to around 2/3, still plenty fast. After a few circuits I did a few rolls, nice and quick, and also a loop. The loop was big and realistic looking (full throttle for that). I went from circuits to figure eights.

I didn't time it, but the 350 2s battery was giving me plenty of duration. When it started to weaken, I lined up for an approach. Good landing in some soft grass, but that tore the weight off completely. It's a pretty clean break, tho, should be easy to fix.

Some observations - This is the PNP version, using a Zippy 350ms 2s 20c battery and Orange R15 receiver. I used thicker wire for the aileron pushrods, otherwise box-stock. AUP weight is exactly 100 grams, 3.5 ozs. That includes the 1/4 oz nose weight. I think keeping these small birds light is a real key to success, extra weight, even a 1/2 ounce, really brings up the wing loading. I'm going to remove the nose weight, glass the nose, then add whatever is necessary to get the cg. I'm planning on removing the fan hatch weights and gluing the hatch, maybe the combination of nose glassing and removing those weights will get me the cg.

One more note - remember where I said it was real sensitive on roll? I went the wrong way on the expo setting - I made it more sensitive instead of less! Now that I've fixed that, really looking forward to more flights.
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Old Nov 14, 2011, 05:57 PM
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Angelo's Avatar
Chicago, IL
Joined Nov 1999
2,058 Posts
Quote:
Originally Posted by giuseppi View Post
Angelo,

Which orange receiver is it?

g
Orange R15. So far, working well, the light weight, size and price are impressive.
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Old Nov 14, 2011, 06:00 PM
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fly time's Avatar
Renton, WA, US
Joined Oct 2007
1,291 Posts
Quote:
Originally Posted by m_ark View Post
This.... plane...(t-45)
Thanks! Guess I'll go browse for some smaller batteries now. Of course, I went and bought 2 of the "recommended" 500mAh batteries, so now I guess I will have to find something else to fly them in Actually, a perfectly good excuse for more airplanes
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Old Nov 14, 2011, 06:11 PM
Gravity sucks.
Australia, QLD, Toowoomba
Joined Mar 2011
563 Posts
Quote:
Originally Posted by fly time View Post
Thanks! Guess I'll go browse for some smaller batteries now. Of course, I went and bought 2 of the "recommended" 500mAh batteries, so now I guess I will have to find something else to fly them in Actually, a perfectly good excuse for more airplanes
Don't sweat it - i have 2 as well, kinda disappointing, but i figure it'll make a nice pack for my RC'd multiplex fox.

in the meantime i have 2x 360 3s on the way.
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Old Nov 14, 2011, 06:24 PM
I AM SOFA KING WE TODD DID
wavekatcher's Avatar
Iceland, Westfjords, Ísafjörður
Joined Mar 2011
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Quote:
Originally Posted by Angelo View Post
Orange R15. So far, working well, the light weight, size and price are impressive.
Did the rx come w/ a bind plug? Ive got all these parts coming , just curious how you bound it to your DX6i
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Old Nov 14, 2011, 06:40 PM
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fly time's Avatar
Renton, WA, US
Joined Oct 2007
1,291 Posts
Quote:
Originally Posted by m_ark View Post
Don't sweat it - i have 2 as well, kinda disappointing, but i figure it'll make a nice pack for my RC'd multiplex fox.

in the meantime i have 2x 360 3s on the way.
Just ordered a pair of Sky Lipo 350mAh from HobbyPartz (that's right HobbyKing - steer me wrong and I will steer away!). They are 10 grams lighter than the 500's. Man, batteries sure are cheap now! $2.10 each
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Old Nov 14, 2011, 06:44 PM
Gravity sucks.
Australia, QLD, Toowoomba
Joined Mar 2011
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Quote:
Originally Posted by wavekatcher View Post
Did the rx come w/ a bind plug? Ive got all these parts coming , just curious how you bound it to your DX6i
just use a screw driver, short the bind plug terminals whilst adding power and the bind sequence is initiated.
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Old Nov 14, 2011, 09:00 PM
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JGuilty13's Avatar
United States, MI, Royal Oak
Joined Nov 2005
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My receiver just showed up. Wow this thing is small....
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Old Nov 14, 2011, 09:30 PM
Check your six
martys's Avatar
New Jersey
Joined Sep 2002
1,240 Posts
Quote:
Originally Posted by Angelo View Post
Got my Orange receiver yesterday, it's tiny! The plugs from my PNP F-86 popped right in.

Now the problem; I want to bind the receiver to my DX6i, but HK din't supply a bind plug. No instructions or info at all, either. I figure I can just follow the binding instructions with the DX6i, but I still don't have a bind plug. Can I just put a jumper across the 2 pins, or is there more to it?

Thanks,
Angelo
Angelo PM me your address and I will send you a couple of bind plugs. Marty
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Old Nov 14, 2011, 11:04 PM
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Angelo's Avatar
Chicago, IL
Joined Nov 1999
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Quote:
Originally Posted by wavekatcher View Post
Did the rx come w/ a bind plug? Ive got all these parts coming , just curious how you bound it to your DX6i
I just put an alligator clip across the 2 bind posts, that worked fine.
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Old Nov 15, 2011, 04:49 AM
The stalling italian
gionir's Avatar
France, RA, Lyon
Joined Jan 2011
297 Posts
Just a quick video of a short but adventurous flight with the MiG 15.
A bit out of control sometimes I have to admit, very proud of the landing tho

Cameraman is still familiarising with tripod and manual focus, so we both will have to practice more

In the meantime I decided to repaint the Sabre, which was battered to the point of non return.
As soon as I can print some decals I'll post pictures. It's going to be awesome!

Enjoy.

JPower 35 mm MiG 15 cruising around (1 min 12 sec)
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Last edited by gionir; Nov 15, 2011 at 05:34 AM.
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Old Nov 15, 2011, 05:37 AM
310mph Kolibri T25 Swist
henke's Avatar
Sverige, Kronobergs Län, Ljungby
Joined Jan 2001
4,821 Posts
Mig29 has 1:1 thrust to weight ratio useing a 2S 450mAh 25C Hyperion battery. weight is 156grams.

Does the ESCs handle 3S???
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