Electric Wright Stuff B

[cctl29]

Thank you Coach Brian and Coach Chuck for your responses. It is very helpful. The projects you mentioned seem to be lots of fun. Another thing we learned from EWS is that knowing what to do is very different from actually doing it. New problems always seem to come up unexpectedly when we actually perform the adjustments, which makes it more interesting and challenging.

Cannot wait to try out some of the outdoor free flight models you mentioned. Now that we have some EWS airplanes of which we are no longer afraid to subject to some kind of damage/injuries, we wonder if we can just fly these airplanes outdoors in weather Coach Brian mentioned in your response? If not, what kind of modifications we can do to make them fly better outdoors? Thanks in advance.

[coachchuckaahs]

You technically COULD fly them outdoors, Josh Finn does. But it needs to be extremely calm. These, while heavy for indoor models, are very lightweight for outdoors, and any breeze will take them away. In addition, they could easily catch a thermal and go out f sight. Normal outdoor models that have any real duration will have a "dethermalizer", a timer that will then do something like make the stab hinge to a high angle, to cause the plane to just float vertically down and end the flight. Most outdoor events have a "max" time, and there is no need to exceed that time (no more points).

Coach Chuck

[coachchuckaahs]

You technically COULD fly them outdoors, Josh Finn does. But it needs to be extremely calm. These, while heavy for indoor models, are very lightweight for outdoors, and any breeze will take them away. In addition, they could easily catch a thermal and go out f sight. Normal outdoor models that have any real duration will have a "dethermalizer", a timer that will then do something like make the stab hinge to a high angle, to cause the plane to just float vertically down and end the flight. Most outdoor events have a "max" time, and there is no need to exceed that time (no more points).

Coach Chuck

[iflycheeseburger]

Coach Chuck and Coach Brian, thank you very much for your suggestions. My airplane has tuned a lot, with the nice circle size and turn! The flight time is also longer than before.

One observation is that after launching, it climbs to the peak height/roof very quickly, in two to three turns. I want to tune it more gently to change height and hope to take more turns to go up. Could you please give suggestions how to tune it further? Thank you!

[coachchuckaahs]

Taking only 3 circles to climb is not unusual for EWS.

Finer adjustments can come in two areas:

1. Motor/prop matching. Are you charging to full capacitor (3V)? If not, you could try a smaller prop or one with a little less pitch to reduce climb power, then charge more to get to teh ceiling. If you are getting to the ceiling with a nearly full charge, then I would not worry about the climb too much.
2. Overall trim. You can flatten the entire flight a bit by moving CG forward, or reducing decalage (wing incidence relative to tail incidence) a bit. Which one to change will take experimentation. This year's EWS seems to like a flatter flight than WS does, and flies faster. Generally you adjust the plane for cruise and letdown, but making it fly flatter will also reduce your climb rate.

Again, the plane spends more time in cruise and letdown than in climb, so the adjustments you make should favor such. But planes with the best times that I have seen tend to zip around faster and flatter than I am used to with WS, and doing that will reduce climb as a byproduct.

Set up an experiment with variables. Start with CG and decalage, and adjust one, then optimize the pother, and repeat until you find a two-variable optimum. In any case, you want to reach the girders, so that (altitude in flight), not your charge, is the fixed value. If you have the means, you can then add variables of prop pitch and/or diameter, though it is hard to make small adjustments. A smaller prop, in pitch or diameter, will have less power. A larger diameter prop will have more power, but also likely more efficiency. But the only way to go larger (more efficient) while reducing power would be to go to a different motor, and there just are not too many options available for quick ordering.

Coach Chuck

[iflycheeseburger]

Thank you, coach Chuck. Will try and see how much we can improve it.

[iflycheeseburger]

Update: we finished state competition, ranked in 2nd, even the EWS didn’t perform as our gym test. After a long transportation, one airplane was damaged, the other didn’t turn correctly. Air conditioning was on and also affected a lot. Wish you all have a smooth competition!

Really appreciated coach Chuck and Brian for your suggestions and help!

[coachchuckaahs]

Glad to help, and congrats on your finish!

For SO, since flights are limited in a competition, we transport the planes in rather large plastic tubs so that they can stay assembled. These planes are VERY sensitive to max altitude (lose several feet you may lose ten or more seconds), and the altitude can be affected by small changes in incidence. Measurements can get you close, but test flying upon re-assembly is absolutely needed to repeat your testing performance.

Air on is a pain. And it all depends how the air is introduced. If the vents blow downward right over the flight path, it is hard. generally you will want to set up a little more stability (move CG forward, raise wing incidence), and then wind or charge for a higher ceiling. Having tested this also helps, even if testing is in still-air conditions. Knowing what the stable setup is, even if it reduced time a little in still air, is important to game-day adjustments. If you already charge fully (ideal), then you may need to have a larger prop to power through the air (normally would take you too high).

But good job improving throughout the season, and making it count at State level!

Coach Chuck