Trimming your plane - hands off

[danskis]

After 3 seasons of flying with no instructor I'm still learning (of course it won't stop). When I first started I was happy just to get the plane launched and have it go in the general direction I wanted it to - instead of some random direction that seemed to have no correlation to what I did with the transmitter. After that I was happy just to go home from the field with no repairs (still am). Slowly I learned to do some basic aerobatics including rolls, loops and Immelmans.

I've recently maidened a couple of new planes and as I was flying one of the other pilots said "you should trim it out" What he meant was the plane should be trimmed to fly straight and level with half to 2/3 power hands off. I don't usually do this but I did for these two planes. What a difference it makes the next time you fly. The plane is totally predictable, it goes where you point it with smooth controlled turns and is a joy to fly. If you're not doing this I highly recommend you give it a try.

Of course the next thing is to make sure its balanced correctly. I've heard your plane should be able to fly inverted with very little stick input if its balanced correctly. Would a better pilot than me care to comment on this?

 

[Merv]

...Of course the next thing is to make sure its balanced correctly. I've heard your plane should be able to fly inverted with very little stick input if its balanced correctly. Would a better pilot than me care to comment on this?

I would not recommend using inverted flight as an indication of correct CG. The wing type will have a huge effect on inverted flight. A flat bottom wing will always require quite a bit of stick input to fly inverted. While a symmetrical wing will require much less stick input to fly inverted. The amount of down thrust will also effect inverted flight.

Where the plane balances is a personal choice, it depends on how you want to fly. On all plans, there is a CG range, it’s usually between 25-30% of the mean average cord, MAC. If you want a more stable flight, use the lower throw recommendations and move the forward CG location. If you enjoy more twists and tumbles, as I do, use the higher throws and use the aft CG location.

Planes are much easier to fly when trim your plane to fly straight and level at the speed you want to fly. I prefer flying at full throttle.

 

[XSrcing]

I trim all my planes to fly hands-off at 50% throttle, but CG is far and above the most important aspect of having a decent flight.

Nothing beats using your fingertips, but stall characteristics are a good indicator of having a CG fore or aft too far.

Aft CG will tip stall in to the dirt.

 

[Bricks]

It is a good idea once trimmed make the trim mechanical and get your radio trims back to zero or as close as you can. ( especially if utilizing flight stability ) Being foam the plane is changing a little warp here and there don`t be surprised if each day have to tweak the trims. This is part of my first flight of the day for each plane I fly, is checking trims whether a foamy or 30cc balsa. Both inverted and right side up.

 

[mastermalpass]

It is a good idea once trimmed make the trim mechanical and get your radio trims back to zero or as close as you can. ( especially if utilizing flight stability ) Being foam the plane is changing a little warp here and there don`t be surprised if each day have to tweak the trims. This is part of my first flight of the day for each plane I fly, is checking trims whether a foamy or 30cc balsa. Both inverted and right side up.

I mustn't forget, on my next build, to put some U bends in the pushrods to allow for easy adjusting. Though usually, 'cause of the wind, I'm used to always leaning on the stick with my small models.