2016 rules

[calgoddard]

Offering bonuses for wing chord reduction does not lead to any airframe design variations.

I did not see a single home made prop on any airplane at our regional and State WS competitions last year. How about a 5 - 10% bonus for using a prop with a home made hub, spar and blades? Students would then learn more about blade shape, pitch and dynamic balance.

[bernard]

Offering bonuses for wing chord reduction does not lead to any airframe design variations.

I did not see a single home made prop on any airplane at our regional and State WS competitions last year. How about a 5 - 10% bonus for using a prop with a home made hub, spar and blades? Students would then learn more about blade shape, pitch and dynamic balance.

I really like what bjt4888 says in this post (specifically that trying to achieve a lower mass if the minimum were lowered would only be possible with homemade props).

[leetx]

In my humble opinion, I think many of the SO competitors are ready for a next challenge: the use of variable pitch propeller (VP).

The design, construction, and operation of the VP is a great engineering challenge. It's perfect for the low-ceiling flying encountered by most students in their gyms. Yet, it is not necessary to reach the already great flight times achieved by many students this year using flaring props. Its use could achieve even better times, but it would take more effort, too.

For 2016, I would keep all rules the same but remove all restrictions to the propeller.

[chalker7]

Hopefully those in charge will write the 2016 WS rules to encourage and reward experimentation in airplane design. It's discouraging to see virtually every team fly the same airplane at each WS competition year after year.

Trust me, we are aware of the issue and definitely want to fix it. The problem is everyone purchases their kits from one or two manufacturers. I can't think of any clear way to encourage variety in an enforceable way. Of course, we could ban kits but that would be completely unenforceable by the vast majority of event supervisors (it would turn into an honor system, encouraging students to lie.) There simply isn't an easy solution, all of the suggestions on the thread thus far are fun, but wouldn't prevent someone from just using a legal kit (that looks the same as all the other kits.) I think the twist we've come up with for next year will make some progress, but I would anticipate students to still create generally similar looking models.

In my humble opinion, I think many of the SO competitors are ready for a next challenge: the use of variable pitch propeller (VP).

That is absolutely not true. I think the exact opposite, only a small percentage of the highest achieving competitors are prepared for VPs. The proper usage of VPs requires a very in-depth knowledge of how these models fly, most importantly a detailed understanding of torque curves. At nationals, I would estimate less than 10 teams used torque meters. If we assume these are the best teams in the nation (clearly not all of the best Wright Stuff competitors are there, but the general idea is valid when you compare them to new teams entering regionals for the first time) then the numbers aren't even close. Only a small percentage of teams even have the tools to record the data required for VPs, let alone the understanding of how to use them. If we get into the construction aspect (constructing a VP is HARD), not a single team at nationals built their own propellor. I don't know what the numbers are at state or regional tournaments, but we can safely assume it is low. If we wanted to get to a step where VPs are allowed, we would definitely have to build a skill base across the country where teams are comfortable building their own props. I assumed the experience everyone had with helicopters would build that expertise and people would be building their props this year, but apparently that isn't the case...
If we were to allow VPs, what would happen is a small number (I imagine less than 10 in the entire country) would build them, use them at regionals/states and absolutely blow everyone else out of the water. If you have the skills to build a VP, you are likely going to win already and I don't see a difference in winning by 15 seconds vs. 2 minutes. In fact, it's a negative to me since it can be pretty dejecting if you are the one on the losing side of that equation.

If you really want to build VP's (and you should! they're awesome), I would HIGHLY suggest you start building indoor models and going to AMA events. It is a lot of fun, very rewarding and a great step up from SO.

[bernard]

Trust me, we are aware of the issue and definitely want to fix it. The problem is everyone purchases their kits from one or two manufacturers. I can't think of any clear way to encourage variety in an enforceable way. Of course, we could ban kits but that would be completely unenforceable by the vast majority of event supervisors (it would turn into an honor system, encouraging students to lie.) There simply isn't an easy solution, all of the suggestions on the thread thus far are fun, but wouldn't prevent someone from just using a legal kit (that looks the same as all the other kits.) I think the twist we've come up with for next year will make some progress, but I would anticipate students to still create generally similar looking models.

I think that people suggesting changes here aren't interested in banning kits since kits are extremely helpful when building your first plane, but rather want rules that would make more experimentation with design possible without hurting flight times.

I think kits should be always allowed not because a ban on kits would be unenforceable, but because kits help students who have never done the event before get started and move on to experimenting with a plane, where a lot of the learning happens.

If we wanted to get to a step where VPs are allowed, we would definitely have to build a skill base across the country where teams are comfortable building their own props. I assumed the experience everyone had with helicopters would build that expertise and people would be building their props this year, but apparently that isn't the case...

With the 8 gram minimum, it was possible to use heavy Ikara props provided by many kits without exceeding the minimum.

[leetx]

One reason that very few home-made props were used this year is that there is very little advantage. It's not that the students don't have the skills.

Removing restrictions from the propeller doesn't mean that everyone will use VP's. Same that many competitors used the stock non-flaring propellers of the freedomflight kit. Only the more advanced students used flaring props. I'm recommending VP's instead of flaring props for the more advanced students.

Building a VP from scratch could be challenging. However, this could be overcome if a kit were made available.

Using a VP is challenging, but in my opinion, many students would attack it with fervor. When I say "many", I don't mean a large percentage. Rather, I mean the many students who are on this forum, who are motivated and actively seek knowledge and improvements. Out of those students who use a flaring prop, some of those would consider using a VP.

I know one student this year who used a torque burner. Why is a torque burner allowed if only one student in the whole country took the time to build and master its use? If it is allowed, why not a VP? Using a VP would teach the students much more about engineering than using a torque burner, which in my opinion is a gimmick.

Respectfully,

-Kang

[retired1]

I still think that a ministick AMA with double the min weight model solves all of the problems.
Since commercial props that would be suitable for this model are ultra few if any, it would require students to make their own props.
They would be more compatible with the low ceilings that most of us have.
They would use a lot less materials, including rubber, so would cost much less, so many variations could be built. (and quicker)
They would be easier to transport for all, especially those at long distances.
There are few kits available at this time and most of those would be far too light.
Check in would be very simple- a box and a balance.

If Bill Gowan has problems with his VP, I would not like to see it in WS.

Does anyone have a better idea for solving all of the mentioned problems?

[bernard]

Since commercial props that would be suitable for this model are ultra few if any, it would require students to make their own props.

Homemade props can be difficult for many students, though maybe you're thinking something similar to what Brian said earlier in this thread where a lower minimum mass would allow an 'unofficial bonus' for teams that make their own props and are able to build lower mass planes?

There are few kits available at this time and most of those would be far too light.

Kits are important for students getting started with flying, though I would expect kits to be made for whatever rules are decided.

[retired1]

Props for a mini stick can be ultra simple. Plain flat "paddles" are not uncommon for these.
There is more than enough information on line for HS students to achieve a decent prop.
As you say, kits will become available in a couple of months after the rules are out.

[bernard]

I'd like to mention that rules are written so that the event is 'entry level' (i.e. any student without much experience could get started). However, prohibiting devices such as variable pitch propellers shouldn't be because they aren't entry level.

I suppose one could say allowing advanced devices that help flights can 'disadvantage' students that don't have the knowledge, but they likely wouldn't have won anyway, since a lot of students compete with planes that aren't trimmed.