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Old Jun 15, 2008, 05:44 AM
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I have a set of Century Jet retracts in my H9 P-40 but having problems with those as well. Will probably just set it up stock for now and see what others are using as more of them should be airborn soon.
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Old Jun 15, 2008, 02:10 PM
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Finally flew mine for the 1st time today (Sunday, June 15, 2008).
Mine came in with an all up weight (including 'fuel'/ batteries) of 160.6 oz, or just a tad over 10 lbs.
Don't know why weighs so much more: I used 1 oz servos for the most part, but did add 2 more servos (1 servo per retract), and I added retractable tailwheel.
It needed downtrim: wanted to take off too quickly and wanted to climb at any and all power settings, so I just about used up my available downtrim.

And despite my added weight, I am quite satisfied with my modest 600 watts of available power. Takeoffs are quick, and top speed was, well, FAST!
Nontheless, I will eventually install the 4 blade prop, which will increase power to about 700 watts

NOTE: I do not consider this model to be completed, as there are many things that I want to do to it yet (like add more decals and the gear doors)
Last edited by CorsairJock; Jun 15, 2008 at 02:31 PM.
Old Jun 15, 2008, 07:27 PM
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Very Very Nice CorsairJock, I'm glad to see another one flying. My build will commence soon as I have finished my other big project.

I'm glad she flew good for you.

~Matt
Old Jun 15, 2008, 10:11 PM
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Larry had his back in the air today.
Old Jun 15, 2008, 10:18 PM
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Hey CorsairJock, did you balance yours in the middle of the suggested range?
Old Jun 15, 2008, 10:40 PM
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Quote:
Originally Posted by Art Newland
Hey CorsairJock, did you balance yours in the middle of the suggested range?
I had a hard time moving mine back to the suggested range. I settled on 5 1/2".
KEY POINT(s):
The recommended elevator throws on low are 3/8" up and down: GOOD ADVICE!

Mine needed some elevator downtrim, and from what I am hearing from others, that also is GOOD ADVICE!.
Old Jun 17, 2008, 03:08 AM
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Ordered a set of Lado retracts for this kit. Now, just not sure if I should build this first or my H9 1.50 P-47.
Old Jun 17, 2008, 09:50 AM
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Definitely the P-47
Old Jun 17, 2008, 10:09 AM
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Quote:
Originally Posted by CorsairJock
I had a hard time moving mine back to the suggested range. I settled on 5 1/2".
KEY POINT(s):
The recommended elevator throws on low are 3/8" up and down: GOOD ADVICE!

Mine needed some elevator downtrim, and from what I am hearing from others, that also is GOOD ADVICE!.
Yes, have to agree about the down trim. And the elevator is quite sensitive with recommended high throws (5/8 IIRC) and -30 EXPO.
Old Jun 17, 2008, 04:20 PM
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Quote:
Originally Posted by Art Newland
Yes, have to agree about the down trim. And the elevator is quite sensitive with recommended high throws (5/8 IIRC) and -30 EXPO.
Actually, Top Flite impies that the 5/8"/ hi rate is more for "taking off from rough grass". I think what they are really saying is that the lo rate/ 3/8" is what should be used for most flying.
Again, my advice: stick with the 3/8" up/ down.

And as for expo: It should be noted that it should be NEGATIVE (at least on Futaba radios), and I prefer about 32 ~ 36%.
Old Jun 19, 2008, 09:27 PM
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3 more successful flights this evening. Winds were calm, so I had a good chance to perform some slow speed tests, both clean and dirty. Of course I grabbed some significant altitude first, just in case, but I was really amazed at how well it flies at slow speeds. Never did stall it, but got it to just slowly descend.

Before the flights, I did some mixing on my Tx: I made the throttle master to the elevator, so now the elevator goes up about 1/16" when at idle, and resumes to normal position at full throttle. The mix is linear, so it does so gradually (assuming throttle changes are done gradually). The result was about what I expected: very predictable, yet slow landing approaches. I made 3 fairly good landings. I say fairly good because it did have a tendency to bounce a little, but not enough to cause any noseovers or damage.
All 3 landings were done with full flaps, and motor at idle.

SO, to sum up my setting:
elevators are now fixed (not using dual rates) at 3/8" up and down, with expo set at -36%
Elevator trim is set about 1/16" below level, BUT mixing moves it up to level when throttle is cut.
CG remains at 5 1/2" aft of fuselage at wing.

This is working REALLY well for me, I'm thinking maybe some of you have too much elevator throw, AND moving the CG too far forward make the nose want to drop too rapidly as it slows down. That's what it appears to me happened in the (electric powered) video: it just sorta dropped onto the runway.

I just joined the Battle Creek Balsa Bees R/C club, and will be attending a social event at their field this Sunday. I am sure that I will be able to get some videos then.
Last edited by CorsairJock; Jun 19, 2008 at 09:33 PM.
Old Jun 19, 2008, 10:57 PM
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Sweet CorsairJock,
Oddly enough, the winds were calm here also. I got some great pictures of the lake like glass.

Now I cant wait to fly mine. I'm going to start my build soon, in maybe a week or so. [I probably said that last week] I have to finnish my major project this summer and the P-51 is 2nd in line now that I finished one of my big projects. So to say the p-51 is next in line but the major project is always first. This is getting confusing.

I will also be attending a fly-in this weekend up here hosted by the TRAMPS. Maybe one of our fellow modelers will have one of these completed and flying there. We will see. There are always many warbirds there so I will take many pictures.

~Matt
Last edited by MattZC; Jun 19, 2008 at 11:02 PM.
Old Jun 20, 2008, 06:53 PM
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Looking forward to the video, CorsairJock.
Old Jun 22, 2008, 05:50 PM
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Video:
Top Flite 1/7 scale P-51D Mustang ARF Electric Powered (3 min 37 sec)


This was the 3rd flight of the day, all on the same charge, so this flight was relatively short. Camera man was, well OK. I've seen better videos, and I've seen much worse. Didn't really catch the gear going up, amd missed the big loop (maybe I should have told him what I was about to do), but some pretty good shots as well.
I was deliberately flying slow near the end of the flight, and managed to get the right wing to drop, but recovery was very quick.

Thru trial and error, I have determined that it is best to land on the mains. Attempts at 3 point landing result in bouncy landings: apparently the main wheels get too far ahead of the CG when I attempt 3 point landings.

Sure wish those Robart parts would come it, it will look SO much better when I can install the gear doors.
Old Jun 22, 2008, 07:29 PM
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Very nice flying!

Just curious you said in your post that you didn't charge your batteries between flights? I had always read that was a bad thing to do, because the ESC always reads voltage when it's connected, that's how it determines the low voltage cutoff.

Mark


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