Dynam PBY Catalina canted Vertical Stabilizer

[chavezding]

Hi guys!

Does anyone here know what's the best way to straighten out a bad design of a foam fuselage? The vertical stabilizer out of the box is tilted lower on the right side when the horizontal surface area is mounted.

This pic shows how the right side is lower.



Thanks!

Ted

[doctormike]

RE: Dynam PBY Catalina canted Vertical Stabilizer

A big hammer, but seriously, I think it would be difficult to shim. I would try diagonal braceing. I'm not sure, but the full scale plane might have braceing on the stabilizers. Look up PBY photos. Good luck, Doc
[hr]
I looked up PBY photos. It doesn't have external braceing. Aside from you, I doubt if any one would notice. This does seam to be the only solution. This is a common problem. I hope someone has a better idea. Doc

[chavezding]

RE: Dynam PBY Catalina canted Vertical Stabilizer

I wish Dynam would make a V2 of this model. She is so easy to fly. You guys think if I dunk the entire tail section in hot water, I might be able to bend the vertical stabilizer more upright?

My wish list for the Version 2:

1. Correct the tail section, even with the main wing.
2. More robust mounting screws to connect the main wing to fuselage. I permanently cemented the wing to body. I did not trust the two tiny screws to secure the wing.
3. Don't make the wing struts slotted on the fuselage. So it won't slip off during flight. I had to cement mine to the fuselage.
4. Add a second push rod to the elevator.
5. Beefier control horns. Both rear control horn on my elevators broke off at the tip.
6. Add brighter LED lights.
7. More magnets to secure the cockpit.

[Loneflier]

RE: Dynam PBY Catalina canted Vertical Stabilizer

Hi Chavezding,

I am glad you are enjoying the Catalina. She is a great flying plane. I've had mine for a couple of years, and always enjoy flying it. I like your idea for a V2 with those upgrades. Mine didn't have the horizontal stabilizer leveling issues, but rudder is very weak on mine, and I usually end up flying mostly with the ailerons. If I ever fly it off water, I will need to fix that rudder throw problem though. She would be easy to take off and land on water, but I need to be able to turn it back to me once it lands!

Good luck with yours. I think probably some struts would correct your issue, and really wouldn't be too noticeable.

[Propguy]

Mix on controller Mix/aileron master / slave rudder add +30. youtube. rudder will be automatic when ailerons are activated.

[Propguy]

Steaming hot hand towels wet and microwave for 90 seconds or so. Too hot for your bare hands. Keep wet. Placing them on the right side, will re-expand the foam and apply slight pressure back to vertical. Mine was 39 degrees off center. Easier and better than the pot of steaming water recommended by rcmotion tech.

[Propguy]

I am a civil aviation pilot. On prop planes there is always right rudder needed either manually or by trim set. Cessna's, pipers, etc.. But the adverse yaw on this Catalina PBY literally flying sideways to the left. Pre-set the rudder to +7 or 10 degress to the right to imitate the rudder trim or do it on the controller? What cha think????

[fhhuber]

I am a civil aviation pilot. On prop planes there is always right rudder needed either manually or by trim set. Cessna's, pipers, etc.. But the adverse yaw on this Catalina PBY literally flying sideways to the left. Pre-set the rudder to +7 or 10 degress to the right to imitate the rudder trim or do it on the controller? What cha think????

Adjust ailerons for differential throw so the ailerons move up more than down. That combats adverse yaw. The source of the adverse yaw is increased drag due to the aileron moving down. The process that creates additional lift also creates drag.

Differential throw can be accomplished mechanically or by computer radio. Mechanically: with the stick neutral and control horn on the bottom of the aileron, you make the pushrod longer and adjust the servo arm to recenter the aileron. If the control horn is on top of the aileron you make the pushrod shorter and then adjust the servo arm.

I prefer to do the major part of differential throw mechanically and fine tune with the computer function.

[TiredIronGRB]

All of the Dynam Cats are like that to some degree, I just carefully twist the tail straight.

[rifleman_btx]

Its because they pack them so carelessly. Thinking crumpled paper is gonna actually save it from bouncing around

[Propguy]

Cannot find the CG on this Catalina PBY

[fhhuber]

Cannot find the CG on this Catalina PBY

Sometimes with really heavy pendulum effect of a high wing, you need to go to the plumb bob methd to find CG.

Hang the airplane from a harness made by figure 8 a string around the fuselage ahead of the wing, through a cup hook (crossover of the figure 8) and around the fuselage behind the wing. The string needs to only be knotted to make it a continuous loop. No other knots.

Hang a plumb bob (weight on a string) from the hook. The line length should be set to have the weight and string not touch the airplane.

the plumb bob will point at CG regardless of airplane orientation. This is a point in 3D space, not a line through the wing. So you want to adjust the airplane in level flight attitude to see the CG in relation to the wing for measuring distance from the leading edge.

Looking from the front you can see if the airplane is heavy on one wing too.