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Old Nov 19, 2012, 01:00 PM
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dahawk47's Avatar
United States, TX, Keller
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Jim,,

That was not too bad. Could have been alot worse !
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Old Nov 19, 2012, 02:23 PM
Unrepentant Carnivore
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Brandon, Fl
Joined Mar 2005
2,509 Posts
Capt momo

Same thing. I see more crashes on take-off due to pulling up before the plane has airspeed to fly. And then the pilot looks into every possible explanation - p-factor, bad ESC, sunspots, flatulence... but the root cause is yanking back on the stick when the plane get light but does not have enough airspeed. As you progress to bigger and heavier models, simple motor grunt will not get you out of trouble. Take your time and use the runway to build speed, then fly. You will notice in the video that I use a lot of runway, partially because it looks good but also so that I don't have to fight to get and stay airborne.

Jim
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Old Nov 19, 2012, 02:25 PM
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Brandon, Fl
Joined Mar 2005
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Quote:
Originally Posted by dahawk47 View Post
Jim,,

That was not too bad. Could have been alot worse !
Yep repair is 80% done. The shaft is 3mm and I have a few spares. The motor dissembles quite easily. I will use my vise as an arbor press to change out the shafts.

Jim
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Old Nov 19, 2012, 03:01 PM
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United States, CA, Oceanside
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The plane definately has enough airspeed because it lifts off on it's own, but after about 3-4 feet, it banks hard right and slams into the ground. He is flying off an asphalt runway and into the wind. The gentleman also flies a Flyzone Cessna 182 Skylane and he flies that one very well. The problem started when he upgraded the motors I think because it flew fine stock.
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Old Nov 19, 2012, 03:05 PM
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United States, TX, Keller
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If the motors are exactly the same spec, then I'd reset the esc's. Try that and if that doesn't work, hook up a wattmeter to test the output from each motor. One last check might be a severely out of balance prop. Process of elimination.
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Old Nov 20, 2012, 10:57 AM
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Retired Relic's Avatar
United States, AZ, Tucson
Joined Sep 2009
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this may be a silly comment............
OK
you checked ESC, watts, amps etc etc

?Are they both rotating in the direction you want them to?
?Do you have a counter rotating prop on?

These are really dumb questions. But DANG we've all been there.
Flying with the wrong model dialed up on your radio.
Watching to see if your servos are working, even if they are moving the wrong direction.

Anyway you get the idea.

best of luck
chuck
PS you can always go back to stock.
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Old Nov 20, 2012, 12:23 PM
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Well, it isn't my plane so I can't answer all those questions, but my buddy has flown this one before with counter rotating props. It wasn't until he upgraded the motors to more powerful brushless that he started having these issues. He had about 30+ flight on it until then.
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Old Nov 20, 2012, 01:13 PM
Don't Move I've Dropped My Nut
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United States, AL, Huntsville
Joined Feb 2009
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Quote:
Originally Posted by chucksolo69 View Post
Well, it isn't my plane so I can't answer all those questions, but my buddy has flown this one before with counter rotating props. It wasn't until he upgraded the motors to more powerful brushless that he started having these issues. He had about 30+ flight on it until then.
Could be that one (or both) of the stock ESC's are not up to the task of the "more powerful" motors???
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Old Nov 20, 2012, 01:18 PM
warranty expired
NOTAR 600's Avatar
Central Ohio
Joined Nov 2007
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Quote:
Originally Posted by chucksolo69 View Post
A friend has one of these and he has since upgraded the motors and propellers to be counter rotating. The last two times he has tried to fly the plane, it gets airborne and then immediately rolls to the right and crashes hard. He is now on his third wing. Do you all think it could be the ESCs not putting out the same RPM to the left prop as it is to the right? It used to fly fine with the stock setup.
May not be this.....but after reading his plane flew ok before switching to counter rotating....I started wondering if the designers of the grand cruiser built some kind of right thrust angle into the motor mounts....to counter and adjust for the torque of both motors spinning the same direction.

Many single motor model airplanes have some right thrust angle where the prop shaft is angled slightly to the right.....because when the prop spins top to the right...then the airplane wants to roll to the left. If the grand cruiser has one or both motors set to right thrust....this might at least partly explain the problem......but it certainly could be a difference in motor/prop speed also....or as someone else said.....could be too much angle of attack on take off causing the plane to stall.

There are a few youtube videos of large expensive topflite nitro powered cessna 310 pilots stalling and crashing on maiden because of pulling up off the runway at much too sharp of an angle.





Mike
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Old Nov 20, 2012, 03:49 PM
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United States, TX, Keller
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Mmmm. So he went with counter rotating motors but did he include counter rotating props ? and are they mounted correctly? That could be the culprit as Relic has suggested above. Worth checking.
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Old Nov 20, 2012, 05:43 PM
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United States, CA, Oceanside
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No, he did use the correct props as he has flown the plane before successfully with them. The problem started when he went to higher KV motors and installed 2 new HK 50 amp ESCs.
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Old Nov 20, 2012, 07:09 PM
Don't Move I've Dropped My Nut
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United States, AL, Huntsville
Joined Feb 2009
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Quote:
Originally Posted by NOTAR 600 View Post
May not be this.....but after reading his plane flew ok before switching to counter rotating....I started wondering if the designers of the grand cruiser built some kind of right thrust angle into the motor mounts....to counter and adjust for the torque of both motors spinning the same direction.

Many single motor model airplanes have some right thrust angle where the prop shaft is angled slightly to the right.....because when the prop spins top to the right...then the airplane wants to roll to the left. If the grand cruiser has one or both motors set to right thrust....this might at least partly explain the problem.....Mike
YES, the GC's motor mounts have about 2 degrees of right thrust offset built in! I checked mine.

-Gary
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Old Nov 22, 2012, 12:56 PM
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United States, TX, Keller
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Okay,

I bit the bullet and just signed up for a GC from Grayson. Bought a lot of motors and miscellaneous things from them in the past and they never let me down. Veteran owned , small business and as close to being a LHS as I can get.

I looked at several civilian twins( B60,C421, P68C Victor, YS-11,etc) and kept coming back to the C310 as having the best value. I still believe there is a big hole in the marketplace for affordable foam electric twins.

Now I'll go back and re-read the threads for the must do mods from all you early adaptors.

Thanks guys. Happy Thanksgiving!

Hawk
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Old Nov 23, 2012, 10:11 AM
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United States, AZ, Tucson
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happy happy
your gonna like it
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Old Nov 24, 2012, 09:30 AM
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United States, TX, Keller
Joined Jul 2011
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CF spar question: My C310 has not even arrived yet but I want to prepare. Have some 6mm dia.CF tube but do you think the dia. is too large? Also have some 2mm square rod.

-Hawk
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