View Full Version : Trimming the Sails
11-27-2006, 02:49 AM
Do you fellows dial in some down elevator for the climb and then erase those clicks when you cut the power? And what about the glide...do you ride the elevator stick to make constant corrections, or do you just use some when you make your turns?
I understand that different conditions call for different methods but how do you do it as a general rule?
And what about rudder in a 3 channel plane? For straight flight, my rudder is at least 10 deg. to the right, even with the power off, so changing the thrust angle won't even out my rudder for less drag. Any ideas on that?
11-27-2006, 03:02 AM
I just ride the elevator with power applied. It's more important to me to have the plane trimmed out well for gliding than during ascent. Even though I fly with a computer radio and could dial it in, I just ride it out of habit.
Is your vertical stabilizer properly aligned? 10 degrees is quite an offset.
11-27-2006, 04:01 AM
If your rudder is off that much somethign is wroing.
Like Don, I manually ride the elevator. When I hit the power on my Easy Glider electric the plane tends to want to climb too steeply. The brushelss motor is strong enough to prevent a stall, but the climb becomes in efficent. I just ride some down elevator into it. Works!
11-27-2006, 10:56 PM
Hi Bud, Like Don and Ed, I manually hold in the "down" during the climb, but only until the glider's trimmed. Depending on the accuracy of the construction (I have 2 ARF gliders, all the rest are kits or scratch) trimming a new glider can take between a couple of flights up to a dozen.
Anyway, after I've flown it with full throttle a few times I get a "feel" for how much down I'm applying during the climb, this is with the main stick, not the trim. Let's say it feels like 6 clicks. I program in 3-4 clicks linked to the throttle. Now I launch under full power and see how it goes. I might slide my thumb over and add 1 more click of down trim. If that seems right, I'll add 1 more to the motor/elevator mix. In other words, I creep up on the setting, because if you're off by even a couple of clicks (too much down) things go bad fast!
My built-in trim is never quite as much as needed for the perfect climb angle. I like to leave that last little adjustment to manual adjustment. This helps me compensate when flying under different weather conditions. As you know, when it's windy, you have to keep the nose further down, the model wants to balloon. When it's flat calm, the opposite; you can let the nose come up a bit more.
During the glide, I almost never move the elevator stick. Sometimes I'll dial in a click of "up" and one of turn when I'm in a thermal to allow the model to find it's own turn diameter and ascent angle. To "cruise" back upwind, a click of down helps, but again, I usually do that manually.
As far as the 10 degrees of rudder deflection, something must be drastically out of alignment. To require that severe of a compensation, my guess would be a wing warp. If you think of warps as a sort of "permanent" aileron deflection, that means you're looking for a warp or mis-alignment that is causing the model to go hard left. So the right wing would be warped down, or the left wing warped up. If not:
Vertical stab lined up with the fuselage centerline?
Wing 90 degrees to the fuselage centerline?
hope you get it sorted out, good luck!
11-28-2006, 02:31 AM
I believe I've got it sorted. I didn't notice the warp in the vertical stab until I put the plane on the floor and stood over it. I torsioned it back with my fingers while holding a heat gun on it until the new wrinkles left. It seems to be holding but I'll check it in the morning. This plane (HL Skimmer 400) spent 3 weeks in a horse pasture. It was waterlogged when we re-united so I stripped the covering off, let it dry for a week, and then recovered it. I guess I'd better check those wings, too.
Your info on climbing and gliding is invaluable and it seems to be a consensus among you.
I'm very grateful to have access to your wisdom. All three of you have been great teachers to me for over a year now. I hope to pass your knowledge on. Really, thanks for your help.
11-28-2006, 03:23 AM
Awwww shucks Bud! :o Ed and Ron are the Kings of explanation that makes sense and are so patient! I think of them as the Gurus of Great assistance!
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