Scioly.org

jander14indoor wrote:

jander14indoor wrote: ↑September 5th, 2019, 7:02 am Oh, a general comment. These rules are NOT written by an individual, definitely committee written. And reviewed by lots of people. So they tend to be compromises between competing ideas (The reason I hate rulings based 'spirit of the rule' when I'm not sure the authors agree on what the 'spirit' is! Though I have used that reasoning at least once...). So don't hate on someone you 'think' threw in a rule you don't like. The responsibility is shared.

Are you speaking from actual knowledge of this or something you've been told? I'm asking this seriously because several of us have a *much* different perception of the rules writing process based on several experiences we've had with SO and discussions with coaches who attend SOSI.

jander14indoor wrote: ↑September 4th, 2019, 11:21 am Though other than the prop, I don't see that much of a handicap...
Last year's tandems, two lifting surfaces, 35X7X2 give a lift area of 490 sq cm.
This year's bi-planes, two lifting surfaces, 30X8X2 give a lift area of 480 sq cm.
Yes I know that the two surfaces on bi-planes don't work as efficiently as a single surface of same area, but that is also true of tandems.
And why are the static margin's so bad. Can't that be adjusted, even with the smaller stab?

The static margins cannot be adjusted without creating an unwieldy, ugly model that is extremely sensitive to turbulence. Like I've said there are several models out now and the flight behavior is extremely disappointing. This isn't about flight times--it's about creating poorly formulated rules which makes the planes unnecessarily difficult to fly.

jander14indoor wrote: ↑September 4th, 2019, 11:21 am We also have a community (concerned over parent built) within SO that likes build on site and doesn't fully recognize the real importance/purpose of this event is test and evaluation. Making the results more dependent on obvious student action during the event helps stave off the (I think overblown) concerns about parent built airplanes.

Well let's be honest, we also have a community within the uppermost echelons of SO leadership who are extremely upset about the existence of purpose-built kits for the flying events. One manufacturer was once approached personally by one of SO's top leaders and asked to either stop making kits that were competitive without modifications or offer multiple designs each season. Given this individual's work schedule, the eye-roll coefficient was predictably high.

Maxout wrote: ↑September 7th, 2019, 12:44 pm jander14indoor wrote:

jander14indoor wrote: ↑September 5th, 2019, 7:02 am Oh, a general comment. These rules are NOT written by an individual, definitely committee written. And reviewed by lots of people. So they tend to be compromises between competing ideas (The reason I hate rulings based 'spirit of the rule' when I'm not sure the authors agree on what the 'spirit' is! Though I have used that reasoning at least once...). So don't hate on someone you 'think' threw in a rule you don't like. The responsibility is shared.

Are you speaking from actual knowledge of this or something you've been told? I'm asking this seriously because several of us have a *much* different perception of the rules writing process based on several experiences we've had with SO and discussions with coaches who attend SOSI.

jander14indoor wrote: ↑September 4th, 2019, 11:21 am Though other than the prop, I don't see that much of a handicap...
Last year's tandems, two lifting surfaces, 35X7X2 give a lift area of 490 sq cm.
This year's bi-planes, two lifting surfaces, 30X8X2 give a lift area of 480 sq cm.
Yes I know that the two surfaces on bi-planes don't work as efficiently as a single surface of same area, but that is also true of tandems.
And why are the static margin's so bad. Can't that be adjusted, even with the smaller stab?

The static margins cannot be adjusted without creating an unwieldy, ugly model that is extremely sensitive to turbulence. Like I've said there are several models out now and the flight behavior is extremely disappointing. This isn't about flight times--it's about creating poorly formulated rules which makes the planes unnecessarily difficult to fly.

jander14indoor wrote: ↑September 4th, 2019, 11:21 am We also have a community (concerned over parent built) within SO that likes build on site and doesn't fully recognize the real importance/purpose of this event is test and evaluation. Making the results more dependent on obvious student action during the event helps stave off the (I think overblown) concerns about parent built airplanes.

Well let's be honest, we also have a community within the uppermost echelons of SO leadership who are extremely upset about the existence of purpose-built kits for the flying events. One manufacturer was once approached personally by one of SO's top leaders and asked to either stop making kits that were competitive without modifications or offer multiple designs each season. Given this individual's work schedule, the eye-roll coefficient was predictably high.

Jeff knows from personal experience. It's possible some events have rules written primarily by one or two people, but I know that doesn't happen for Physics events at least, and very confident that the same is true for Tech events given what I've heard.

"A community within SO" can include parts of the Executive Board. Presumably parts of the Exec Board have a different opinion, since if they were universally agreed the rules would have been changed regardless of what the Rules Committees thought (as supposedly happened with Bottle Rocket, although that was before my time).

Unome wrote: ↑September 7th, 2019, 1:56 pm

Maxout wrote: ↑September 7th, 2019, 12:44 pm

jander14indoor wrote: ↑September 4th, 2019, 11:21 am We also have a community (concerned over parent built) within SO that likes build on site and doesn't fully recognize the real importance/purpose of this event is test and evaluation. Making the results more dependent on obvious student action during the event helps stave off the (I think overblown) concerns about parent built airplanes.

Well let's be honest, we also have a community within the uppermost echelons of SO leadership who are extremely upset about the existence of purpose-built kits for the flying events. One manufacturer was once approached personally by one of SO's top leaders and asked to either stop making kits that were competitive without modifications or offer multiple designs each season. Given this individual's work schedule, the eye-roll coefficient was predictably high.

Jeff knows from personal experience. It's possible some events have rules written primarily by one or two people, but I know that doesn't happen for Physics events at least, and very confident that the same is true for Tech events given what I've heard.

"A community within SO" can include parts of the Executive Board. Presumably parts of the Exec Board have a different opinion, since if they were universally agreed the rules would have been changed regardless of what the Rules Committees thought (as supposedly happened with Bottle Rocket, although that was before my time).

I don't think there is universal agreement on either the appropriateness of kits or the costs/benefits of on-site builds. As a result, you get compromise approaches - as Jeff describes - which seek to have students demonstrate familiarity with the aircraft design while still allowing most work to occur before competition day. This might make the aircraft more difficult to fly or reduce flight times, but Wright Stuff is a relative competition: as long as flight times correlate with skill and practice, and are sufficiently differentiated, their absolute length doesn't seem incredibly important to me.

nicholasmaurer wrote: ↑September 7th, 2019, 4:05 pm

Unome wrote: ↑September 7th, 2019, 1:56 pm

Maxout wrote: ↑September 7th, 2019, 12:44 pm

Well let's be honest, we also have a community within the uppermost echelons of SO leadership who are extremely upset about the existence of purpose-built kits for the flying events. One manufacturer was once approached personally by one of SO's top leaders and asked to either stop making kits that were competitive without modifications or offer multiple designs each season. Given this individual's work schedule, the eye-roll coefficient was predictably high.

Jeff knows from personal experience. It's possible some events have rules written primarily by one or two people, but I know that doesn't happen for Physics events at least, and very confident that the same is true for Tech events given what I've heard.

"A community within SO" can include parts of the Executive Board. Presumably parts of the Exec Board have a different opinion, since if they were universally agreed the rules would have been changed regardless of what the Rules Committees thought (as supposedly happened with Bottle Rocket, although that was before my time).

I don't think there is universal agreement on either the appropriateness of kits or the costs/benefits of on-site builds. As a result, you get compromise approaches - as Jeff describes - which seek to have students demonstrate familiarity with the aircraft design while still allowing most work to occur before competition day. This might make the aircraft more difficult to fly or reduce flight times, but Wright Stuff is a relative competition: as long as flight times correlate with skill and practice, and are sufficiently differentiated, their absolute length doesn't seem incredibly important to me.

I can see the point about instability of the device, but I have other thoughts about that in general which I need to eventually expand upon.

Unome wrote: ↑September 7th, 2019, 1:56 pm Jeff knows from personal experience. It's possible some events have rules written primarily by one or two people, but I know that doesn't happen for Physics events at least, and very confident that the same is true for Tech events given what I've heard.

I'm a member of the tech committee. Before rewriting events, we spend 2 days or so reviewing the results from the previous year, FAQs, clarifications, and tournament feedback. The committee typically reaches a consensus on the overall changes for the next year. Then 3-4 people take that input and write a first draft of the rules. After they've been written, they are reviewed again by the 20 odd members of the committee. Further reviewed by the senior leadership. Then dry runned at SOSI where we get the input from folks who HAVEN'T been part of the rules writing, incorporating suggestions as appropriate. Then final draft and final review before publishing.

All that's part of the reason I'm so careful about answering clarification questions with LOTS of caveats and as undefinitively as possible. Even when I'm the event supervisor I'm only ONE of the people who help make the decision.

Also why I caution folks not to worry too much about the details of next year rules. They aren't even finalized till sometime in August.

SO, now, lets discuss how you deal with the rules this year, cause they are what you have to work with!

Turns.
Typically these planes are trimmed by multiple twists and turns on various parts to maintain a steady turn through the varying power from the prop. What are these, and which can you change on the floor?
Classically we have these planes turn left to deal with the prop torque. This means we typically have the following settings.
Prop thrust down and left.
Wing longer on left side than right.
Left wing washed in wrt the right.
Rear stab tilted left side high.
Left rudder.

Now, which of those can you change on the floor, and how?
- Prop thrust. I see this one as hard. So much force you typically have to lock it down pretty tight. So what do you do? Not sure, but I'd probably trial no left thrust.
- Wing longer on left. How hard to change depends on the design and how you mount the wings. I typically use tissue tubes on the fuse with wing posts firm to wing. I could see a design change that fixes the posts to the fuselage and has two sets of tissue tubes on the wings providing appropriate offset for each direction. Alternatively, keep the tissue tubes, but two sets, one on left side of fuse, one on right. Maybe with an spacer to get more change.
- Wing wash in. Same design change would allow you to change this. Tilt the tubes on the wings such that they twist the wing as needed.
- Rear stab tilt. I've designed planes in the past with adjustable stab tilt. Tail boom was attached to fuse with a tissue tube. Two choices. One, make it a round tube you could adjust as needed. I don't like that, too easy to get it wrong in heat of competition. Alternative, two 'square' tissue tubes. Again, pre-tilted as needed.
- Left rudder. I actually fix the rudders on my designs. left rudder is from the angle of the tail boom. Previous solution would allow this.

How to go about figuring correct settings. Frankly, I wouldn't try to make the first plane that complicated, even for an experienced builder.
I'd build two planes. Trim one to turn left, the other right. Figure out appropriate trim settings to optimize flight time. Then use that info to build the 'adjustable' plane.

Oh, and yes, for first time competitors, focus on making a conventional plane turn left and maximizing its time. Only move onto right turns AFTER you have the experience to do that.

Other proposals?

Jeff Anderson
Livonia MI

I agree, build a plane for left circles, optimize the trim, before looking at right circles. Simplify as much as possible before competition. Anything that must be changed, make it a fixed change. No time for measurements or trim flights.

While we enjoyed the higher ceiling last year, doing WS in ceilings that are not typical high school gyms present challenges that may be hard to overcome (though partial motor testing proved valuable).

More importantly, the higher ceiling extends flight times, driving the rules to a more compromised airframe to limit times. Perhaps the ceiling should be limited?

Our kids are once again looking forward to investigating and solving this challenge. They know it means lots of flying, which is heaven in their minds!

Get in the gym!

Coach Chuck

CrayolaCrayon wrote:You've made a good choice. This is a very high quality event that pays off with lots of testing. Look at this link and go to the end of the thread: viewtopic.php?f=299&t=12123&start=780

That has advice from the end of last year from some of the best fliers in the country (Jander, Chuck, BJT, retired1)

Another place to look is the 2016 WS forums for advice. The knowledge fostered on here will take you very far.

Thank you for this. I've still got a lot more reading to go, but so far from what I've gathered the general basis to doing well is to focus on mainly trimming and gathering data rather than the design (as long as its functional). My only problem with that is I believe I'm only allowed a gym for testing about once a week for 3-4 hours. Would this be sufficient enough for gathering data?

Bread,

As we get close to competitions, once a week is the same amount of time that my teams spend trimming and testing, as long as you start soon. We try to start testing by mid-October.

Wright Stuff (and the other Aero events) are lots of fun and are definitely real Aerospace Engineering and Materials Engineering.

Brian T

I wish I could get that much time in a gym. I was limited to 30 minute-1 hour spurts in the morning. I would come in an hour before school to test, at around 6 AM almost every morning Monday- Friday for 5 months. The gymtime you have is great. Make good use of it!

Alright, thank you both. I wasn't sure how much time was necessary, but I'll be sure to use as much as I can. I am pretty excited so I think I'll bring out some old planes from last year and mess around with them to get a feel for flying when I get the time. Also, before I go back to more reading, are there any predictions yet for time this year? Let's assume a 30' ceiling.