RCU Forums - View Single Post - newbie, sort of.
View Single Post
Old 05-17-2005 | 09:57 PM
  #6  
kitcar
Junior Member
 
Joined: May 2005
Posts: 17
Likes: 0
Received 0 Likes on 0 Posts
From: saline, MI
Default RE: newbie, sort of.

Suggest naysayers take aerodynamics class like I did. Simple effect of lift, thrust and direction, Einsteins' theory correct.

Okay, moved the motors outboard 3" each. In theory, this should increase moment of movement through the axis. Moved the left motor (torque causes left turns under power) 10 degrees to the centerline - that is, I pointed the prop toward the left of the tail (pusher prop) of the plane by 10 degrees; under power from both motors, should stop left shift in flight, figuring the power of the motors at full thrust and full batteries. Added 6" to the center of the wing. Wings now 6" longer, 3" per side. Used Popsicle sticks to strengthen the centerline at the body of the plane.

Went to park, took off from parking lot. Plane drifted to right. This is direct opposite of original design. Shifted weight to left, experimented with center of balance, got it right. Plane now turns nicely to left and right. Made several left hand loops around trees, changed direction and made several right hand loops around trees. Brought plane in to parking lot for landing. Gear collapsed. Used Popsicle sticks to strengthen landing gear, repeated flight, landed; no problems, gear intact. May add rubber wheels around silly plastic wheels at later date. All takeoffs and landings from parking lot, no hand launches. Method is to gain speed, balance direction using thrust, gun motors. Used normal hot glue gun to add mods to frame and body.

Wind speed, 3 mph. Took off into wind. Added weight with mods, 4.3 oz. All weight at centerline of plane (inboard of motors). Adjusted fixed Vtail to add up lift during flight. Original design had plane looping under full power. Now plane just gains altitude, i.e., goes up, not over.

Plane now ready for prime time. Next mod to be servos slaved to motors. Turn left, shifts Vtail in proper direction, Turn right, same action to other direction. Will add crispness to turns.

Answers to questions:

1. Yes, it turns slower than a 3 or 4 channel but not by much. Would turn faster with motors at tips of wings. Wing strength issues with a foamie, may try that later on if I can find correct foam for wings.

2. Wing dip is slower with motors mounted farther out with longer wing length. Stalls not happening at all even under full single motor thrust.

3. Method is to stop motors, tap opposite direction of wanted turn, tap full motor speed to stop wing stall.
Completion of turn, tap out of turn with opposite motor.

4. Flight time, 12 minutes. Batteries not exhausted, approx. 40% amps left.

Video to follow this weekend. Videos will be 45 seconds each (limits of memory in camera).

Now for the downers: mods not for the faint at heart. Takes planning, knowledge and tools at hand. Total cost is rising: $30 for plane, $2 for Popsicle sticks, $6 for foam board for centerline of plane, several thousand dollars for classes. Needed longer screws for Vtail and wing. Had on hand, cost not known.