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Old Nov 29, 2010, 09:31 PM
speedin n da weeds :)
sikky's Avatar
USA, AZ, Glendale
Joined Feb 2008
595 Posts
Dam I'll fly mine in 2 days after it gets here for a $100 bucks!!
We don't need no fights guys.
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Old Nov 29, 2010, 09:33 PM
Renegade Fun Forever!!
rvincent's Avatar
Fontana, California, United States
Joined Jul 2004
27,249 Posts
Yep I was told my A-4 would be a boat anchor too I was told My CMP 120 Spitfire was too heavy at 11lbs but it flies like a kite! Right now I have 4 planes on my work bench. My Falcon 120, my Starfire (actually its at the painter's), my new 120 Spitfire, and this 90mm Hawk. I put this Hawk way out ahead of the others in the build que but for one reason or another I have yet to get her done because of travel, yard work, Christmas decorations this past weekend. But I will get it done ASAP. It won't be any heavier than anyone elses on 8 or 10 cells. Maybe lighter cause of Tam's retracts, Stu's fan, wire struts (for now).
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Old Nov 29, 2010, 09:39 PM
Fly allot, Crash allot, next?
United States, CA, Corona
Joined Feb 2006
7,229 Posts
OH Sikky, wer're not fighting. Just a friendly one way wager, Bob has nothing to loose and if I was with him right now, we both would be smiling ear to ear.
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Old Nov 29, 2010, 09:39 PM
Renegade Fun Forever!!
rvincent's Avatar
Fontana, California, United States
Joined Jul 2004
27,249 Posts
Anyway I love ya Al And I'm not the least bit afraid to fly this plane. Just need time to finish it I had no room to bring it with me on this trip. And that stinks cause here I am sitting in a hotel room watching TV when I could have been at home building...
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Old Nov 29, 2010, 09:47 PM
speedin n da weeds :)
sikky's Avatar
USA, AZ, Glendale
Joined Feb 2008
595 Posts
I just find it really hard to believe not 1 flight report!!!



Not 1!
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Old Nov 29, 2010, 09:49 PM
Renegade Fun Forever!!
rvincent's Avatar
Fontana, California, United States
Joined Jul 2004
27,249 Posts
Me too actually. As many in this thread alone I thought at least one "Epoxy Cowboy" would have galloped it down the runway by now
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Old Nov 29, 2010, 10:03 PM
Fly allot, Crash allot, next?
United States, CA, Corona
Joined Feb 2006
7,229 Posts
I really think that the intention of the manufacturer was to have this plane flown with a 4S to 6S 3300mah battery and very high KV motor. In other words, similar to a foamy with slightly more weight.

I am comparing this T-45 with my Nitroplanes Starfire, 7lbs, 6S battery, Midi Pro 90mm fan with ARC motor. Even with all that the Starfire is not a rocket ship with retracts and the wing area is much much larger than this T-45 that is going to weigh much more.

I say, keep it light, keep it cheap, test fly it before installing retracts. Use the on-line CG computer to verify a ball park reading for the CG. Garbage in will produce garbage out, but another opinion on CG will help. If the leading edge of the wing is straight, do not measure as with a swept wing. A tapered wing is not a swept wing. Enter zero for the sweep.

http://adamone.rchomepage.com/cg_calc.htm
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Old Nov 29, 2010, 10:05 PM
Renegade Fun Forever!!
rvincent's Avatar
Fontana, California, United States
Joined Jul 2004
27,249 Posts
I have 3 other Hawks to judge CG by I ain't skeered
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Old Nov 29, 2010, 10:07 PM
Fly allot, Crash allot, next?
United States, CA, Corona
Joined Feb 2006
7,229 Posts
One note: CG on a real plane does not have to be perfect. With a real plane, the plane can be flown safe if the computed CG is within a safe flying envelope, determined by the manufacturer. This safe envelope is in the airplane manual kept on board the plane at all times. Even commercial jets use a computer to figure if they are safe.

In this CG program the % of MAC is the envelope for an RC model. Use between 5% and 15% and the plane should fly safely.

Hope I helped.
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Old Nov 29, 2010, 10:17 PM
Renegade Fun Forever!!
rvincent's Avatar
Fontana, California, United States
Joined Jul 2004
27,249 Posts
Hey Marvin I just watched the maiden of your F-4. It was clearly an incidence issue. Your horizontal stabs had at least a 4 degree negative attitude so it required a ton of up trim. That up trim fighting the negative incidence is causing the tail of the plane to fly in a constant stall with all that added drag. It wasn't overly nose heavy as you may have suspected because it leaped off the ground with a bump and didn't slam nose first, it tried to fly. I can garranty if you changed that tail plane incidence it would fly much slower and with out all that "washy" roll tendency.
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Old Nov 29, 2010, 10:23 PM
I can fly anything..... Once!
FL62's Avatar
United States, AZ, Queen Creek
Joined Feb 2004
1,131 Posts
Quote:
Originally Posted by rvincent View Post
I have 3 other Hawks to judge CG by I ain't skeered

Bob,
I'll throw in my .02 on the CG.

My JTM Hawk flies best at around 3.75"-4" back from the LE at the wing root, balanced upside down.

Since these hawks have similar moments, with a slightly narrower chord on the CM Pro - I'll bet a good CG will be around 3.25"-3.5" back.
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Old Nov 29, 2010, 10:38 PM
Registered User
Oneonta Alabama
Joined Aug 2010
898 Posts
Hey Mike the JTM Hawk scales out at 1/9.5 onthe Fuse and 1/8 on the wings .I wonder How this one compares to size.Oh and by the way looking forward to your gear door build.
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Old Nov 29, 2010, 10:39 PM
Renegade Fun Forever!!
rvincent's Avatar
Fontana, California, United States
Joined Jul 2004
27,249 Posts
I was thinking 3.25 as well to start with.
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Old Nov 29, 2010, 10:47 PM
Gilbert, AZ
chalmrast's Avatar
Gilbert, AZ
Joined May 2007
3,564 Posts
Quote:
Originally Posted by SCALEFAN View Post
I really think that the intention of the manufacturer was to have this plane flown with a 4S to 6S 3300mah battery and very high KV motor. In other words, similar to a foamy with slightly more weight.

I am comparing this T-45 with my Nitroplanes Starfire, 7lbs, 6S battery, Midi Pro 90mm fan with ARC motor. Even with all that the Starfire is not a rocket ship with retracts and the wing area is much much larger than this T-45 that is going to weigh much more.

I say, keep it light, keep it cheap, test fly it before installing retracts. Use the on-line CG computer to verify a ball park reading for the CG. Garbage in will produce garbage out, but another opinion on CG will help. If the leading edge of the wing is straight, do not measure as with a swept wing. A tapered wing is not a swept wing. Enter zero for the sweep.

http://adamone.rchomepage.com/cg_calc.htm
I agree 100%. Mine will be approx 6.5lbs on a 6S-1900kV setup. 1700-1800 watts with a thrust tube diameter of about 72mm. I am basing the AUW from Herb's weights of his parts.

Matt Sylvester's ProDesign Mig 15 flies over 115mph on this setup and the plane is almost the exact same size and weight. Not apples-to-apples I know!! but, same overall size, weight, power, and construction.....

And Al, you can call me Chad instead of "Gilbert, AZ."
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Old Nov 29, 2010, 11:04 PM
Registered User
mpope1's Avatar
gilbert,az
Joined Dec 2005
3,948 Posts
Chad, I am gonna order the same system as you and Matt. Matt proved that its solid, fly's his Mig real nice and also your L-39! You have a link where I can get it at?
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