Espritmodel.com Telemetry Radio
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Old Dec 08, 2012, 09:49 PM
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Ok the prop is missing as I'm waiting for new one. As for the CG at the moment its where there a red mark behind the centre spar.
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Old Dec 08, 2012, 10:51 PM
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ok, it looks like your battery is still too far back. You can also move your ESC forwards. Here is where I had to have my 500mAh 2S Lipo when I first built the plane, in order to get my CG where it is supposed to be.

photos
Battery location (left)....................ESC location (right)
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Old Dec 09, 2012, 06:50 PM
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any luck yet on your CG issue?
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Old Dec 09, 2012, 07:04 PM
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Looks like a ton of glue, much of it behind the CG. Tape and carbon on the back end isn't doing it any favours either.

How much does it weigh without the battery?
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Old Dec 09, 2012, 08:00 PM
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Right the weight without the prop and battery is around 209g. The only thing iv added is the carbon spar on the leading edge of the wing. I have to admit I used hot glue for the spar but for the rest I used foam glue. The spar I added is ahead of the CG so if anything it should help with the weight in the front of the plane.

panther3001, I have moved everything far forward as you have advised but still more or less the same. I will try tomorrow with the prop and see if it makes any difference.
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Old Dec 09, 2012, 08:40 PM
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Wow. looking at your plane again, and the weight, I really think you over-built the plane, and the only thing you can do now is to keep adding weight as far forward as possible until it is balanced. I used ONLY hot glue on my plane (with 2 minor exceptions: 1) shoe goo on the motor mount, and 2) CA on the carbon pushrod joints to the metal z-bends), as I am a huge fan of hot glue for foam planes (when used carefully/sparingly, and wiped off), and my total plane weight came to 186g without the battery (yours is 23g more than this), and with the prop and ESC and Rx and main wing carbon spar and all, after my initial build. My original RTF weight, *with* the 35g 500mAh Turnigy 20~30C 2S LiPo and a 9g aileron servo, was 221g. Yours, with the 35g Lipo would be 244g, with much of that extra weight being in the tail it appears (this is bad for CG balance).

Here's where I see you may have overdone it:
1) too much glue
2) you have two carbon spars in the tail it appears (one in horiz. stab, and one in elevator). I have none in the tail.
3) what size servos are you using? I am using a 9g servo for my ailerons only, and for the elevator and rudder I am using 5g servos. If you are using 9g servos, those will shift the CG back too.
4) what size pushrods are you using? I am using a 1.5mm solid carbon rod to the rudder, and a 2mm solid carbon rod to the elevator.

Again though, I think your real killers are 1 and 2 above. I only have a single 3mmx2mm hollow carbon tube in the main wing, and nothing in the tail. Having even a very minor amount of weight (glue and carbon) in the tail could cause the main problems since the moment arm is so long from the desired CG location to the tail.
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Old Dec 09, 2012, 09:06 PM
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Could be possible I used too much glue
I didn't add the spars in the back only the one on the leading edge of the wing which is 1x6mm. Im using 3x 5g servo and the push-rod are the ones that came in the box (1.5mm). I might try and relocate the elevator and rudder servo further up and see if that makes much difference.
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Last edited by dinislam1395; Dec 09, 2012 at 09:16 PM.
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Old Dec 09, 2012, 10:30 PM
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cool, good luck. you'll get it. practice makes perfect.
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Old Dec 10, 2012, 08:16 PM
...just an earth bound misfit
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Yikes. mine is now up to 187g without prop & battery, and it's a bit of a porker in my view; I've got some balsa & hot glue on the nose to reinforce it following a few dirt naps.
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Old Dec 12, 2012, 11:19 AM
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Ok did a little weight reduction and I got it to 196g(measured properly this time). Now to get the CG right. I measured one one of the spar I put on and it weighs 7g on its own.
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Old Jan 14, 2013, 01:10 AM
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Hi everyone. I just got a kit like these as a gift. It will be my first build like this, since I usually get pnf/pnp planes. Could someone help me concerning the location of the servos? Where should I stick the elevator/rudder servos? Should I simply stick it on or make indents in the fuse and glue them in? Thanks.
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Old Jan 17, 2013, 08:58 PM
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Look at my post #422, and see attached picture for how I did mine. I just stuck them to the side using a small amount of hot glue. It works great. The location is pretty clear from the picture, but don't be fooled by the extensions on the ailerons (the plain white foam portions), as that is an extra piece of Depron that I hot glued onto the back of the original ailerons to increase their size and effectiveness in hovering. Note the locations in reference to the original parts of the plane.
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Old Jan 21, 2013, 07:12 AM
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Quote:
Originally Posted by panther3001 View Post
Look at my post #422, and see attached picture for how I did mine. I just stuck them to the side using a small amount of hot glue. It works great. The location is pretty clear from the picture, but don't be fooled by the extensions on the ailerons (the plain white foam portions), as that is an extra piece of Depron that I hot glued onto the back of the original ailerons to increase their size and effectiveness in hovering. Note the locations in reference to the original parts of the plane.
Thanks for your time pal! I managed to put the rudder servo under the wing (I extended the original pushrod given in the kit) but had no option with the elevator servo, it had to go to furthest point possible @ the back of the wing. CG seems fine on the bench, will have to test! I was forced to do this since its a pita to ship pushrods to my country, the cost isn't worth it just for 2 rods.
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Old Feb 23, 2013, 01:13 PM
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Hi friends! Thats my Hawk 3D 80 with a new decoration made by me







Equipment:

9x5 Slowfly Propeller
ADH300 1100kv Motor
Hobbyking HK-20A ESC
3x HXT900 9gr servo
Turnigy Nanotech 25-45c 3S 850mAh

And it flies very well
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Old Feb 23, 2013, 07:09 PM
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looks very nice! Does it hover well? Is that spraypaint?
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