Tweaks for 2021

[OpticsNerd]

What do you all think should be tweaked for the rule replay next season?

[CrayolaCrayon]

Increased stab area, potentially larger prop.

[Dreamz]

IMO only increased stab area is needed to make planes easier to trim. Would be interesting if they gave us the option of a "biplane" stab config with the current dimensions.
Even though it's a pain to work with, I think a larger prop would just make times longer, which is the exact opposite of what the rules committee wants. Would be nice to have though

[bjt4888]

I agree that the most important change would be to increase stab size to around 37-40% of wing area. This one change would make the airplane trimmable. And, yes, the very small propeller was going a bit too far, in my opinion. With a prop spinning at around 2,400 rpm, many teams found that prop damage was a pretty discouraging regular occurrence.

My preference though would be for a completely new set of rules. Most of the significant challenges have been solved for this years rules (I know that it is still hard to execute without error even if you have solved). If SO wants to try something different, they might consider a much lighter airplane with a very limited rubber motor weight. Students have had this experience with the 3.0 gram helicopter from a few years ago and I think they would enjoy something like this for WS. Also, as this would be new territory, lots of room for analysis and testing.

Brian T

[OpticsNerd]

I agree that the most important change would be to increase stab size to around 37-40% of wing area. This one change would make the airplane trimmable. And, yes, the very small propeller was going a bit too far, in my opinion. With a prop spinning at around 2,400 rpm, many teams found that prop damage was a pretty discouraging regular occurrence.

My preference though would be for a completely new set of rules. Most of the significant challenges have been solved for this years rules (I know that it is still hard to execute without error even if you have solved). If SO wants to try something different, they might consider a much lighter airplane with a very limited rubber motor weight. Students have had this experience with the 3.0 gram helicopter from a few years ago and I think they would enjoy something like this for WS. Also, as this would be new territory, lots of room for analysis and testing.

Brian T

I pretty much fully agree with everything you said.

But just to clarify, does 37-40% assume a monoplane? If that's for a biplane I think it might be somewhat excessive if the point of the biplane is to be a challenge. Although even if it was for a monoplane, it'd still be significantly better than it was this season(biplane stabs were 15% this year I think).

As for the propeller, having the propeller break so many times was pretty annoying to say the least. We had to buy so many propellers just to replace the broken ones. I'd think that increasing the max diameter from 8 to 10 cm would make a big difference.

Your idea of a very light airplane with very limited motor mass sounds very interesting. Two years ago when I started WS the motor mass limit made the check-in take too long IMO, and that combined with other factors got me late for my next event at a competition. I'd still be fine with going back to a rubber mass limit, however, and I do think it's an idea worth trying.

[bjt4888]

Yes, 37-40% of the monoplane wing area for a reasonable stab area.

I agree that a motor weight limit is a bit more challenging for event scheduling. I would challenge the event supervisors (me included) to come up with methods and tools to process motors quickly. The best idea I’ve seen is a simple balance scale with the balance arm mounted on a tallish post (around 24” tall) and with a hook at the end of the balance beam to hang the motor on. The balance scale is set to the allowed motor weight and a legal motor brings the “pointer” to the center of the scale readout (or, short of center). Motors (and airplanes) can be weighed very quickly with this setup. The longtime flying event supervisor for the Michigan States built a scale like this and it works great.

Brian T

[coachchuckaahs]

Brian: How about they do something like the Scraps plane (living room flyer size), but limit the rubber? Could be fun! Half a gram is not hard to reach, but could make min weight 3/4 gram?

Coach Chuck

[MoMoney$$$;)0)]

I feel that a cool tweak for next year is to be able to use 2 props, but I feel that this would add to large of an aspect to the plane. Thoughts?

[bjt4888]

Brian: How about they do something like the Scraps plane (living room flyer size), but limit the rubber? Could be fun! Half a gram is not hard to reach, but could make min weight 3/4 gram?

Coach Chuck

Chuck,

That would be fun. Model boxes would smaller and cheaper too.

Brian T

[xiangyu]

Brian: How about they do something like the Scraps plane (living room flyer size), but limit the rubber? Could be fun! Half a gram is not hard to reach, but could make min weight 3/4 gram?

Coach Chuck

Chuck,

That would be fun. Model boxes would smaller and cheaper too.

Brian T

I gotta say, this plane is really hard to trim and hard to fly for me. Also, I think it's really hard for most students to build to weight + make the prop from scratch.

On another note, is there any way to cut down rubber width without a rubber stripper? I'm trying to fly my scrap but the smallest size I have is 0.058 and the plane is torque rolling. I think I just need a smaller size rubber to prevent that...

Xiangyu