2016 rules

[retired1]

A VP prop device is anything but an entry level device. I have a heavy one that is 3 years old and if it had not been a gift, I would not have one.
There are 2 people that sell them, so I guess that it is not much different than buying a kit other than a lot harder to find.
There are probably a hundred or so mentors that can help design a plane from scratch or from one of the many similar designs that are available. Students without good mentors would have a big problem making one from scratch.

I would find it interesting if the rules had a huge bonus for a student fabricated prop. A problem with this is that it would have to prohibit that type of kits. Ikara has one.

[bernard]

Students without good mentors would have a big problem making one from scratch.

Students who do not have mentors already can find help at nearby flying clubs or on forums such as Hip Pocket and Scioly.org.

[retired1]

Rumors from the SO Summer Institute are for less wingspan, less chord, less stab, less rubber and slightly less weight with huge bonuses for carrying coins.
This will be interesting!

[calgoddard]

These rumored changes, if implemented, would be a big disappointment.

Imagine the winning airplane in Wright Stuff flying around at relatively high speed and landing after only 30 seconds in the air.

The bonuses would not teach the students anything except that a heavier airplane flies for a shorter duration, and has to fly faster in order to stay aloft, all other things being equal.

The added weight of the coins will increase the likelihood of damaged airframes due to collisions and crashes. If the extra weight were added to key parts of the airplane in terms of structure, at least it would be of some benefit in the form of added strength.

In the real world, airplanes designed for carrying heavy loads, like the C17, are designed with more lifting area, bigger engines and stronger air frames. It makes no sense, indeed it is dangerous, to add heavy loads to a very light aircraft and hope it can still fly.

[retired1]

But this is one of the purposes of engineering, to find the best way . It may be that the airplane with no coins is better than with one or more coins. There is only one way to find out--experiment!
I think that one of the goals of the WS committee was to shorten the flight time.
Everyone will have the same wing and stab area and airplane weights will be close to the minimum. So the prop and rubber combination becomes the biggest factor. Thin and long rubber or short and fat. Match that with how close to the breaking point you can wind it. Probably no backoff because you want it to get as high as possible (initially) Diameter of the prop will be close to identical, so that leaves size shape and pitch for the optimum.
I think that the top teams will all be over 1 min with a max load of coins.
I think that there is lots of room for experimentation which is the desired result rather than the cookie cutter planes of this year.

[calgoddard]

If the proposed rules with reduced flying surfaces and coin bonuses are formally adopted, the airplanes at the 2016 WS contests will all look virtually identical and will have stock Ikara plastic props.

The airframes would then be a standard mono-plane configuration with the wing and stab both having maximum span and chord. A light weight balsa prop would not survive for long if the airplane weighed, for example, 7 grams and was carrying an additional 3 - 4 grams of coin ballast. Given the high wing loading, the airplane would have to travel pretty fast to stay aloft and the balsa prop would likely be damaged on the first collision.

Successively tape one, two and three coins at the CG on the motor stick, fly the airplane and you find out really quickly which coin bonus is optimum, if any. Not much engineering would be involved in that determination.

Consider what kind of bonuses would have stimulated more creative engineering in the WS event, adding coins (useless ballast) or bonuses for the following configurations:

canard;

pusher;

balsa prop;

bi-plane; or

twin props.

If the goal of the 2016 WS rules is to shorten flights, simply reduce the maximum span of the wing and/or the maximum chord of the wing and/or reduce the maximum rubber motor weight to 1.5 grams.