kloper

Check out my gallery photos. There is one pix. indicating the method I used to operate the split flaps I installed using one HS55 servo. I think that the 27 deg of flaps that I was going to use is too much and will decrease the flaps to about 10 deg. for the first run.
Ken

kloper

Yo RedRaiderFlyer,
Just fired up my GP P38 for the first time using OS 25LA's and found excessive vibration caused by the plastic spinners. I decided to remove them and was able to reduce all of the vibration by balancing the APC 9/6 props and fine tuning the motors.

JAkridge

Kloper,
I hope the LA's are enough with the added weight and drag with the mods you did. Your plane looks awesome.
Sorry the spinners didnt work out. What kind of RPM's are you getting and are the little LA's running OK ??

Good Luck on it's maiden.

kloper

Hi All,
Sunday Oct 8th was the maiden flight of my P38.
The weather was perfect, blue skies, temperature about 68 degrees, wind from one to five miles per hr. right down the runway and the trees are in their fall color.
The pilot, Chris Zonio is a fellow Binghamton Aeros club member who made both flights.
After the first flight we made several adjustments and one was to change
the 6-degree of engine off set to zero. The P38 flew excellent and with out any problems.
Chris made several low passes for pictures. Both flights caused most spectators to turn their heads and look at the P38. The sound of the 25 LA’s in sync. Was to say the least outstanding. Both engines turned about 8800 RPM with APC 9/6 props.

I have added three pictures of the maiden flight to my gallery
Ken

prop

My Feedback: (1)

You're the man, Ken!!! Can't wait to see Glacier Girl in her full glory!!! Congrats!!!


Henry

JAkridge

Awsome.......Can't wait to see the pictures of her complete. Glad the engines worked out for you.

bernd_57

Hi All !
I Build exactly The Great Planes P38 Profile.
Install as Engine the OS FS 20 Four Stroke
If the Model with i flies or the Engine too small

Sorry for my english

Bernd Germany

kloper

Hi Bernd,
I'm not sure about the engines you are using. I used two O.S. 25LA's but had to add about 1 ounce of tail weight to obtain the correct CG.
Have you balanced your P38 yet?

Your english it probably better than my German
Ken

karmann34

My Feedback: (5)

Finally had a day to actually get something done, so I thought I would share the results. Not much really, but it is progressing. I had wanted to change the orientation of the engines in order to let the exhaust go over the top, but decided against that. I did try to hide the aileron and throttle servos inside of the wing. Certainly wish to thank all of the pilots on RCU that provided so much excellent tips while they built theirs. Still deciding if I want to try Ken's operational Flap set up. That may be a little beyond my ability on this, my first box of wood. Thanks to all. Greg

bernd_57

Hi Kloper

The Engines weigh 265g = 9,3 OZ
have not started with the construction of the Modell

By Bernd

SIMCO

My Feedback: (33)

ready for flight

karmann34

My Feedback: (5)

Hey SIMCO, Those are very cool Pro P-38's!! How does the one with the wing tip tanks handle? Do they affect ground effect any?
Hey Bernd 57 in Germany! Have you started yours yet?

Sorry to bring this thread back up, but I am getting closer and feel I need to get advice from the really twinsane pilots out there. Any advise is appreciated. I am so close to starting covering now I can practically feel the heat!
I am trying to do a trial assembly with all the gear that will go in it, including trial set up of the control horns, linkages, etc.. I am hoping this may allow me an oppotunity to balance without adding additional dead weight. I haven't put it on the scale yet, but it already feels like a brick.
There were a couple changes to the elevator and rudders. Basically, I hacked off the small triangle and filled in the rudders. I also added about a 1/4 inch stock to the leading edge of both elevator and rudders.
TT36Pros. 3004 Fut servos, plus 2 little Bluebirds for throttles.
Is it going to be easier to cover all the parts individually or should I actually fully assemle it and then iron on the covering? I have several rolls of monokote, so I'll have enough to practice with a bit.
Thanks again for all your help,
Greg Boswell

kloper

Yo Greg,
If this is any help, I added one once of lead weight
to the tail to obtain the correct CG. I also fabricated the horizontal stabilizer using ¼ inch solid balsa to strengthen the tail from twisting ( as was mentioned in previous statements by other builders). I also fully assembled the P38 and mounted all components to check the CG before covering.
The CG was some what nose heavy and I thought I could move the battery and radio around to correct the CG. However I could not correct the CG and had to add the dead weight on the under side of the horizontal stab.
The P38 flew well as balanced and the OS25 LA’s moved the plane with authority.
Ken

karmann34

My Feedback: (5)

Hi Ken, Thanks for the tips on setting up and getting it CG'd.
I must be the last one building this plane. I see that they're going for about $69,00 now. I'm going to get another one. I have been flying profiles (MOJO's) and learning quite a bit in how they lighten and strengthen them.
So, how did those flaps work out, are you still flying yours? I wish I had time to get something finished on my own. Been buying finished planes from buddies because I simply don't have time to sit down at the table lately. I always thought it would have been cool to build one of these using the all the tips from this thread. Great info. How about one with retracts, flaps, and twin sync. Wonder if a P-38 could hover?
Best regards,
Greg

ABORH

Hello.
I have been having trouble with obtaining reliable engine performance due to to engine vibration causing excessive fuel foaming. The engines are Magnum .28s. I use DuBro 6 oz tanks. The engines run quite well in a bench mount. However the tanks, though padded, shake so much when the engines get past half throttle air bubbles enter the fuel line and the engine will surge[&o]. I am using GP foam for padding and 4 standard rubber bands to hold each tank in place. It seems that each fuse section in front of the wing is not stiff enough. I have considered doing surgery and putting some long carbon fiber rods in to try and stiffen that fuse section, but consider that a last resort. The build is per the instructions without modification.

Other than going to electric motors or the afore mentioned surgery are their any suggestions for controlling this problem. I use S&W 15%. Thanks in advance for your comments.

Johnny C!

ABORH,
Since no one else has responded, I guess I will.
I have not built the P-38, but I do have some twins.

1) I will never use another plastic spinner. I have
been told that if you don't use an electric motor
starter on them, they are OK. But I do use a starter.
I use the solid Dubro spinners, & I have never had
a problem. Get rid of the plastic spinners...

2) Always balance your props. I have had other
modelers tell me that APC props don't need balancing,
but that is simply not true. I balance all props, regardless
of brand or size.

Other than a bent crank, there's not much else, but I don't
use Magnums, anymore, either.

Now, if you ditch the plastic spinners & balance the props,
and it still vibrates, and you still want to fly it, add about
two full squirts of Armor All to a gallon of fuel. This will
eliminate the foaming issues. I had a lot of foaming problems
with 1/2a's, and this did the trick. I did try an off brand copy
of Armor All & I seized a good engine, so don't use anything
else. I have never had any ill effects from this, either. As a
test, tank a few ounces of fuel in a clear container & shake it.
Notice the bubbles. Add a little AA & shake again. It's pretty
cool. I use to add a couple of squirts to every new gallon of
fuel, but I since I have a handle on the vibration causes, I
haven't had to doctor my fuel in a couple of years.

I don't me to demean you, just letting you know what I found.

Good Luck!

Johnny C!

ABORH

Hey! Thank you for your suggestions. I will give them a try!

lbarnes

I know this post is late and hope you have corrected your issues with foaming.

Since the P-38 is a profile and the engine mounts and front of the booms are made of lite ply. When I built mine about 4 years ago I got rid of the light ply, used reg ply and added sheets of 1/16 ply to both sides of the front booms. This gave me additional strength and the engine vibration was reduced due to stiffer engine mounting.

Even with this I still get some vibration and my fuel will boil but not foam. I have not had any issues with fuel foaming.



Good luck

Larry

FA82Showtime

Hey what size and kind of 3 blade prop are you all using. I gonna be putting on some GMS 32's i want 3 blade for looks. and to fly with. It calls for 8x6 to 9x6 2 blade i cant find anthing close other than a master airscrew 9x7 three blade is that the right prop. Its also first time running three blade props so i just donno.

lbarnes

If you want the looks, then static with 3 bladed props, but fly with 2 blade. I have 2, .25 magnum XLs and use APC 9X5 - 9X6 props.

Thought it would be cool with 3 blades. Put the 8 x 6, 3 blades on and could barely keep it in the air.

Made 1 flight, pulled the 3 blades off and went back to the 9 x 5 APC.

Just my $.02 worth


Larry

bernd_57

Hello

My P38 already flew
I converted the model into a control line model
The Engine two OS 25 LA
The Fuselage must be supported because of vibrations
Here the reconstruction into pictures sorry only in German
http://www.rc-network.de/forum/showthread.php?t=105623

Sorry for my englisch

Greetings Bernd

lbarnes

Nice job on the C/L conversion. Just goes to show that anything can be done if you put your mind to it.

I have been thinking of modifying some of the C/L planes into R/C.

It would be something that not everyone else has.

Larry

WD4JKH

My Feedback: (8)

I had an old SIG Banshee someone gave to me that I converted to r/c. Stripped off the tissue covering, added a new rudder and put a .40LA on it. I had a ball with that thing until the wing folded on it one day...

lbarnes

I also have a Voo Doo C/L that I have been kicking around for a long time. Thought of the same thing.

Some of the older stunt C/L planes really look cool and have thoughts of going in that direction.

Larry

FA82Showtime

I gonna run 2 micro servos for throttles, what torque and speed should i need, or what servos would be best
Thanx
Brad