You must Sign-in or Register to post messages in the Hobby Squawk community
Registration is FREE and only takes a few moments

Register now

Announcement

Collapse
No announcement yet.

Dynam DC3--

Collapse
X
Collapse
First Prev Next Last
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Dynam DC3--

    Was looking at the Dynam DC3 and also the C47 version. Noticed on both that Number 1 and 2 motors are pointed way down. Looks really wierd. Was wondering if maybe the motor mounts could be shimmed to let the motors sit more in line with the aircraft centerline. It would look 100% better, but don't Know how it would affect flight performance. Any thoughts?

  • #2
    Hi exf4mech, thank you for your service and welcome to Hobby Squawk!

    The Dynam C-47's props are not counter-rotating. The thrust line you see in the motors/props is necessary to fly the aircraft straight; straightening the shaft angle will noticeably degrade the aircraft's handling.

    Dynam's are on the simpler, straightforward side of the twin foamy spectrum. FlightLine twins like the F7F and P-38 use counter-rotating props and much straighter shaft alignment. But, they're also larger and more expensive twins compared to Dynam twins.

    Comment


    • #3
      The alignment of the motors is designed around being able to keep control (hopefully) when flying with just one motor working.
      Yes, you can have "single engine out" with these electric power models. ESC failure, a wire coming loose or a prop coming off are some ways it can happen even while the ESCs are both connected to the same battery.

      You can find some pretty extreme looking thrust lines on full scale aircraft for the same reason.

      The the motor on the left needs more offset than the one on the right if both use a standard (right hand rotation) prop.
      The further the motor is from center-line of the fuselage (center of drag) the more offset it needs.

      If you ever have a "single engine out" DO NOT turn toward the dead engine side if you can avoid it and keep your turn as flat as possible (use rudder to turn and ailerons just to keep wings level)

      If the left side quits in a normal banked left turn, the nose of the plane being pulled around to point the model down might be your first clue.
      If the thrust lines were set without expecting to occasionally operate with one engine out, you could not recover without turning off the running motor.
      Even with the offset, you may need to reduce power to recover.

      Some twin engine airplanes do better single engine out than others. All have their worst issues at lower airspeed and high power (right at take-off) due to reduced rudder authority to deal with the offset thrust.
      FF gliders and rubber power since 1966, CL 1970-1990, RC since 1975.

      current planes from 1/2 oz to 22 lbs

      Comment


      • #4
        I have had two of the Dynam C-47/DC-3. They are good flying planes. Many folks, including me, removed the downward thrust of the motors by nipping off the top standoff spacers on the motor mounts. This has two benefits, one it improved the appearance of the plane and two, it improved the ground handling a bunch. (The plane has a tendency to want to nose over on grass runways, reducing the down thrust of the motors improves taxing on grass.) It had little to no effect on the plane in the air. I also switched to MAS three blade props, going to a counter rotating set. It isn't needed, the plane flies great as it comes, but it is a simple matter to reverse one motor by switching any two wires from the ESC to the motor.

        Comment


        • #5
          Those look really good wv. I nearly pulled the trigger on the HK bare foam kit but it sold out by the time I made up my mind, I want one bigger than the dynam. It’s a beautiful plane.

          Comment

          Working...
          X