clt12981

Just ordered new Kyosho Pitts Special S-2c 50 EP 2 days ago. Sure hope I haven't made a mistake.

Does any one know anything about this plane.

I plan on using a Power 46, 60amp esc, 4200mah 4s Thunder Power, 10amp Castle bec and 1320mah2s TP with AP6200.

Any input welcomed.

Chuck
http://www.kyosho.com/eng/products/r...duct_id=101717

pvtzemerak

what a buitifull plane, keep me updated.
--pvt

haze_b

Aloha Chuck,

I've always known Kyosho to make a quality product. Should be no worries there. I've flown a friends earlier version. It is a beautiful plane. Just an fyi-- every Pitts Special I've seen has been a handful to fly, so you might want to keep your control throws on low rates until you get used to her. (it is VERY aerobatic.)

Good luck, I'm sure you love her.

clt12981

Maiden flight for my new Kyosho Pitts Special S-2C 50-EP, 46 span, 5 pounds 4ounces. New bird set-up, Power 46, Phoenix 60 ESC, TP-4200mah3s, AR6200 Receiver with TP-1320mah2s, castle 10amp BEC and HT225MG servos.

Throttle up slowly straight down runway, tail dosn't lift 3/4 throttle she's airborne. I know this is going to be fun by the way she is surging up and down (like it's tail heavy). Make smooth right hand turn, trim in a lot of down elevator and a little right aileron & she's flyable! Try loop she rolls out at top of loop. Go inverted and she will do an inverted loop by herself. Rolls pretty.

Well 6 minutes go by time to land, this will be fun, when you slow down she starts the surging up and down again. Oh well, whew she's down with only a small bounce.

Now the big question; is she tail heavy or nose heavy. C/G is set according to specs. A couple people tell me that the factory specs were wrong. There is about 1/4 inch down elevator trimmed in her.

It's mid afternoon 90 degress and seems like a 100 pilots at the field, will make slight C/G addjustment and try again in a couple of days.

Any suggestions on set ups please advise.

Thanks Chuck



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Sabrehawk

On most any bipe I've seen, and I have three of'em myself the CG should be straight up from the leading edge of the bottom wing. That is if you looked at the plane from below, where ever the leading edge of the bottom wing overlaps the top wing mark that on the bottom of the top wing and thats your CG. And the range should be about 1/4 in. forward or back of that point.

Thats exactly where it is on my Art Tech Christen Eagle, and the other two bipes I have. (Curtiss Jenny, and a profile 3D Christen Eagle.)
Just looking at yours Im gonna bet that it comes out right on or just a tad forward of the rear bolt on the top wing's center mounting bolts.

It was a good flying buddy of mine who told me of this bottom wing leading edge thing, and of course I checked and sure enough he was right.

Oh, and hey thats a sweet looking Pitts, im anxious to hear of how she flies once the CG is corrected. The Pitts and all its derivatives are always crowd pleasers, and fun and frolic'y to fly.
Say Chuck ya know in that second pic from the left you could pass for George Carlin ya know that?
I could thnk of all sorts of Carlin one liners for that pic.

clt12981

That's pretty close to were it is. Mine is even with the back upper brace for the upper wing. Did that make any sence? LOL

Thanks Chuck

P.S. I've heard that about Carlin before.

Sabrehawk

Yep well I geuss we can go forward with it 1/8" or so, not much though it wont take much to change the flight handling in this short tailed beauty.
But if you got 1/4 in. of down trim in to hold level flight at half throttle or a click or two over(thats what I trim all mine to) that then I'd say the CG does need to go forward. She shouldnt need that much trim, in fact to me any plane should fly rightly with it's tail surfaces neutral with zero trim.
If it doesnt, then shes not balanced or somethings out of whack with the tail.

Fly Time

I've been looking around for a "big" electric plane that isn't actually all that big. This Pitts looks like it fits the bill nicely. Any more opportunities to fly it? Impressions?

haze_b

I aggree with Saberhawk! You definitely want to fly will minimum trims set. You should definitely adjust your CG ballance point forward. Flying a tail heavy Pitts should be a bit "too exciting". At least for me

Good luck!!

clt12981

Well, same old same old.
After many flights and many changes, moving CG for and aft, moving motor forward up to 1/2 inch, trying 4 cell and 6 cell batteries to add forward weight, having so much forward CG it won't even do a loop, changing top wing incident, a couple of things remain constant.
No matter where CG is set it still requires down elevator trim to maintain level flight and it still likes to climb when inverted. Myself and at least 6 members of the Jax,s RC are not able to figure it out.
Have returned CG to about 1/8th inch forward of specs and with about 1/4 inch down trim on elevator it flys decent, and thats where I shall fly her.
If any one is thinking about trying the Kyosho Pitts I would say beware. If you still want one you can have my airframe for $100.00 Dollars, local pick up Jaxs, Florida.

Thanks all, Chuck

Sabrehawk

Well dad burn'it Chuck, sorry its giving ya fits on this. Hmmm, well the only thng left is motor angle. And that would have to be not enough downthrust.
Now I cant see much from the photos except in the last one to the right, and in that pic it looks like the shaft is pretty well centered in the cowl opening. Most any plane I look at one can usually see the shaft angling downard through that opening. But I'd have to see a profile shot with the plane sitting level to tell for sure, and even then its still hard to see in a photo. And is best measured with an instrument that can gauge it against the wing chord line.
It should measure out to about 3 degrees.

Hmmm, well I had a good look over this plane's manual, specificly steps 19 & 20 and aside from mentioning about the offset lateral centerline of the motor in leu of angling it to the right(I've seen this done before, on my L-19.) But it doesnt show any downthrust info.
To my knowlege any plane should have 2-3 degrees down thrust.
Wouldnt be the first time the engineers left something like this out, so ya might try putting washers on the top two mounting bolts between the mount and the firewall to obtain some downward angle, and see if that does it.
Other than that im out of ideas.

Fly Time

So this looks to be a two-Chuck thread

Chuck (Sabrehawk) might be on to something with thrust angle, but I suspect it may be a matter of TOO MUCH downthrust. It may even need some up thrust.

Now I realize this isn't a perfect comparison, but I have a profile foamie Pitts that flew terribly with downthrust (Chuck, you've seen this odd bird fly). The manual said nothing about it, but I took it upon myself to shim some in, and it would snap out of loops, and actually flew better inverted than right side up. I eventually took out the thrust angle and it flew MUCH better.

Since the thrust line of the Pitts is centered between the two wings, the drag created by the wings acts equally against the thrust, so no need to compensate with thrust angle. In theory that is. It could be that some up thrust would improve flight, especially if you see that it is rising under power when inverted.

Sabrehawk

Yeppers I have seen it fly, a wierd little bugger wasnt it?

Heheh, a two Chuck thread............thats good Doug.

Well, im gonna stick to needing down angle on it, from how I understand thrust angle and it's effects. Too deep to go into here though, LOL!
Im betting that with a couple degrees down, this will give downward pull to the nose, thereby forcing the tail up and hence the elevator will have to be trimmed back to neutral to equal things out.
Of course if he does give it some downthrust and if it does what I think it will, he'll need to have the trim at neutral before taking off cause with it trimmed down 1/4 in. it'd be a bear to keep controlled like my mustang was when I took off with it and it was constantly trying to dive on me and I never got a chance to get my thumb on to the trim lever, was too busy with the stick trying to avoid disaster. Too scared to take my thumb off it.

Much easier to trim out too much up than down, at least when you release the stick to get to the trim lever it wont be nose diving into the pavement.

clt12981

Sorry I didn't specify, but among those many changes I made was changing thurst angle, up and down. The only change I could see it made with a lot of down thurst in it was, it seem not to climb as much when inverted. How ever down trim in elevator did not change.
Thinking about cutting ( can't think what you call the sbab that holds the elevator. LOL ) stab looose and changining it's angle to match amoumt of down trim. Only other thing I can think of.

Chuck.

Sabrehawk

Well there is one thing I havent thought of here. Chuck, at what throttle setting are you trimming her for level flight?
The throttle setting you trim the plane to fly level at will determine where the elevator's position in the end.

I normally trim for level flight at or about half throttle, of course this considers that the power pkg is about right, and normal. By normal I mean not grossly overpowered, nor underpowered but about what the real plane would be. If it is powered in a normal range then half throttle would be about right to trim it to. That should have your airspeed healthy enough, and the elevator should be inline with the stab or very near that.

For in the end what we are really trimming is the airspeed that the plane is going to fly at, so if you trimmed it at say 3/4 throttle the elevator will be at a negative position, and the airspeed would be greater. And you could for instance trim it at full throttle to fly level and she'd be flying at it's maximum airspeed possible. But then you wouldnt be able to climb, only descend.
So what im driving at is that where the elevator will wind up at, weather down, level with the stab, or up will depend greatly on where the throttle is at the time you trim it. So if you had the throttle at say somewhere above half that would be why the elevator is 1/4in. down.

Just more food for thought.

Ok, im outta here as im goin down south for some flying, eating, smokin, shootin some guns & the breeze and more flyin.