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Old 10-23-2007 | 01:27 AM
  #2125  
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Patto
 
Joined: Dec 2005
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From: Eugene, OR
Default RE: Showtime


ORIGINAL: HoverLoW

Hi. Thank you, guys, for the fast aswers.

Hey, P-Diddy, in your signature says you do have a Showtime powered by BCMA 26cc.

Is this a gas engine? If yes, this engine must have the sames power and weight of the 160FX, haven't it??

If yes again, how your engine flys the Showtime?

Mine, with 160, was really awsome!!!!!!

But I noticed some problems that I think is about the weigth:

- Was very hard to make inverted harries, becasue the plane started a inverted flat spin;
- A HUGE snap tendence (http://www.youtube.com/watch?v=us35LQWSK9w);
- A good amout of dead weight on tail to bring back the CG (210g);

The inverted harries was my big problem, becaues I couldn't t pratice this maneuver on my Showtime.

Of this things, my Showtime was perfect. So, did you notice some things like thoses?
Maybe, have I a CG problem never solved??
Yes, the BCMA 26cc is a gas engine, and although it isn't as powerful as the O.S. 1.60 glow engine, (gas engines of the same displacement will always be less powerful) it still pulls the Showtime around with authority. The BCMA engines are very lightweight for gas engines, and I did not have to add any extra weight. I just moved the Rx battery pack toward the tail until it balanced. Then I built in a ply holding plate for it.

The snap tendency is present in many planes that have 3D throws and performance, and the ST is no exception. I was always ready with the aileron when pulling hard on the elevator. If I pulled full up, it didn't snap at all, just entered a wall and I hovered from there. The BCMA 26 has plenty of power to pull out of a hover.

Harriers, whether upright or inverted, can be pretty challenging with this plane. I found that pulsing the power helped to keep it from wing-rocking too much.

I have only ever flown one plane that didn't have ANY snapping tendencies or rolling-out tendencies during hard elevator maneuvers, and that is my Aviation Models 33% Yak 54, (a.k.a. SD Models and TOC). I have flown many other 3D capable aircraft and have found that they all do this to some extent, with only that one exception. For me, it is not a deal-breaker. I do what I can to minimize the rolling-out by putting a small amount of negative incidence in the wings, laterally balancing the plane, and ensuring that both elevators move evenly. Then, I just plan ahead for when the plane wants to roll or snap.

The ST is plenty capable of 3D and pattern, (I won 1st place in a small Sportsman pattern competition using my ST with the BCMA 26 in the nose).

Unfortunately, I recently traded mine with that engine for a helicopter set-up, but the new owner of the ST really likes it a lot.

-Pat