tim thompson

I have aroyal c-47 want to put saito .40's in it. Twinman, is this enough engine? Also what canyou tell me about the wing b-25

Tim

twinman

My Feedback: (2)

The subject of this list of discussion has a 96" wing span and is using two OS LA .46's, which is not a particularly strong engine, but it pulls this plane will. I believe you should be fine, but use props for thrust, and not speed.
As for the wing B-25, cannot comment as have not flown it or any
B-25...sorry,
Good Luck

warbirdz1

Tim....I dont own a Wing B-25 but have seen 2 of them fly and seemed to do ok.....the smaller you get with warbirds.......the more attention to weight/wingloading is required....It seems to make a nice project....I believe its around 84" W/S...........Bill....

Edwin

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A guy in our club flys one. He uses OS .72's and says it flys pretty fast. Its glassed and painted. Looks real good in the air.
Edwin

Holeshot

Lookie here......TopFlite did the R&D for you!!!!

(I downloaded the TopFlite 1/14 (82.5" span) scale DC-3 manual, here's some quotes)

"SCALE ACCURACY
The Top Flite DC-3 is a faithful reproduction of the full size aircraft, with a few exceptions. Flight testing of the prototype models showed the need for some changes to improve stability so that the average sport modeler could handle this twin engine model.
1. The chord at the wing tips has been increased by 8% to improve the stalling characteristics.
2. The scale airfoil blends into an S8037 at the tip to improve the stalling characteristics.
3. The wing tips have washout of 2 degrees.
4. The engine nacelles have been lengthened by 1/2" to allow room for retractable landing gear.
5. The engine nacelles have been moved 1/2" further away from the fuselage to improve prop clearance.
6. The vertical fin/rudder area has been increased by 25% to improve single engine handling.
7. The horizontal stab/elevator area has been increased by 23% to improve pitch control.
8. The engines incorporate 4 degrees of left/right thrust, and 6 degrees of down thrust."

"In order for your DC-3 to handle well when one engine quits, it is important that the outward thrust of both engines is correct. To check this, make a thrust platform by drilling a hole through an approximately 1/4" x 1" x 6" piece of plywood and mounting it to one of your engines. Stand your wing on its trailing edge and
place your Robart Incidence Meter on top of the thrust platform. Read the outward thrust. This should be 4 degrees (if your work surface is level). If necessary, place washers or thin pieces of plywood behind the engine mount until you can achieve the correct outward engine thrust. Measure and adjust the outward engine thrust of the other engine the same way."

"The balance point is shown on the plan (CG) and is located 4-3/4" [121mm] back from the leading edge of the center section of the wing"

"CONTROL SURFACE THROWS
NOTE: Throws are measured at the widest part of the control surface. We recommend the following control surface throws:

High Rate Low Rate
ELEVATOR: 5/8" [19mm] up 1/2" [13mm] up
5/8" [19mm] down 1/2" [13mm] down
RUDDER: 1-1/2" [38mm] right 7/8" [22mm] right
1-1/2" [38mm] left 7/8" [22mm] left
AILERONS: 5/8" [13mm] up 5/16" [8mm] up
5/8" [13mm] down 5/16" [8mm] down
FLAPS: (Takeoff/half-flap) 1/2" [13mm]
(Landing/full-flap) 1" [25mm]

TRIM MIXING: If your transmitter has Flap to Elevator mixing, we recommend mixing 1/16" [1.5mm] of up elevator at half flaps and 3/32" [2.5mm] of up elevator at full Flaps. This will keep the nose level when you extend the flaps."


The last couple of sentences in the following piece are interesting.....

"FLIGHT CHARACTERISTICS
Other than engine-out flying characteristics, there are a few other flight qualities you should be aware of. The engines are placed quite low in relation to the center of the aircraft. This causes a pitch change when power is changed. This is most noticeable when you go from idle power to full power at a low airspeed - such as during a go-around. Be prepared for this, adding a little down elevator until the speed increases. Larger engines make this characteristic more pronounced. The placement of the fuel tanks in this model is difficult. Although the best location for the tanks is in the nacelles, if you are installing retracts the only available place is in the wing center section. Modern engines have good fuel draw so this should not create a problem, but older tired engines may have difficulties. We did not experience any problems with the many types of engines we tested on our prototypes, but we did note one unusual thing: In a
turn the engines will have a slight RPM change. The low engine will decrease RPM by a couple hundred and the high engine will gain a couple of hundred. While slight, this is enough for the aircraft to yaw slightly. It appears that the aircraft is skidding in the turn, and it is! (A skid is where the nose turns into the turn)."

Here's a valuable painting tip from the manual:

"Important: If you are using aluminum paint (as we did on our prototype), do not sand the paint before you apply your clear coat. Sanding aluminum adds a scuffed appearance that the clear coat will not remove. Apply your clear coat directly over the
aluminum paint and it will match the MonoKote aluminum well."

john booth

Thanks for the information, I will incorporate it when I start the rebuild in a few weeks. Hope it flys well and will be sure to let you know

KADET KING

tim thompson

I havent heard any talk of flaps on this bird, was there any installed. Also what was the cg point?

john booth

The CG was 4 inches and no flaps, I used the CG calculator to determine it.

regards

Kadet king

kram-RCU

Are all DC-3's hard to fly (land)? Compare to, say, a large P-38.

I was planning to build the Ziroli next winter, but you guys are scaring me. I don't need another H.A.G. (heart attack generator) in my hangar.

mt

john booth

The DC-3 should be easier than the P38 just make sure you follow the plans and build in wash out