2020 Wright Stuff Parameters

[jajefan]

Would be cool to see a pusher plane again..

I ran out of time to test a pusher this year. The weights are high enough that you could do one without sacrificing rigidity. With the tandems we've got, sliding the CG further aft with a pusher might have actually been the optimum solution.

As for preparing for the rules, well, expect the unexpected. Your best bet is to fly AMA classes and push them as hard as possible. Start with a P-18 kit from Lasercut or one of the advanced indoor kits from other vendors (shameless plug) and step things up a notch. Once you can hit 7-8 minutes with a LPP in a gym, you can challenge anyone at Wright Stuff.

-Josh

besides increased times, what design benefits would a pusher provide?

edit: and how does/would it provide a benefit?

This is only a guess, but I might say part of the increase in flight time might be due to less turbulent airflow over the wings/stab because the propwash goes entirely behind the plane. For a similar reason, reduced p-factor may mean that there is not as severe of a bank angle in the beginning of the flight as you might expect with a tractor config (although most of the time the "torque spiral of death" this year is caused by flexy motor sticks). Additionally, you now have a bit of real estate in the front of the plane to work with a mechanism that may increase the durability of the plane regarding ceiling hits and whatnot, since we had a few issues this year with the ikara props and the prop mount/bearing breaking on ceiling hits (very rare, but still happened).

I don't quite know the feasibility of a pusher plane in kit form, however, as the standard ikara prop would have to be changed to match a pusher config (for those of us that don't make our own balsa props) and/or would require winding backwards (again, depending on the config of the prop) due to the standard flight orientation (turning left circles vs. right circles).

[calgoddard]

The Wright Stuff event has previously awarded a bonus for flying a model with a pusher configuration.

I will try to post a picture showing a design used in the 2008 competition.

The prop on this pusher model is a stock Ikara prop, installed backwards, so that the rubber motor has to be wound counter-clockwise. The blades of the prop may have been trimmed to meet the max diameter allowed in the Wright Stuff rules for that year. The spiral ramp on the prop hub needs to be filed flat. The end of the prop shaft opposite the hook is secured to the hub so that the wound rubber motor can drive the prop hub.

My recollection is that the Wright Stuff pusher design shown in the picture was developed by the late, great Cezar Banks, who was a legendary indoor flier.

It is well-known by experienced indoor fliers that a pusher configuration is typically not as efficient as a tractor configuration (prop in front) on indoor models. I could speculate as to why but that would probably not be constructive and outside the scope of this post.

However, as I recall the 2008 Wright Stuff bonus for using a pusher configuration was sufficient to make it the preferred configuration for those seeking to win the Wright Stuff event. The bonus may have been 15-20% of the flight time but I could not locate a copy of the 2008 Wright Stuff rules.

Maxout - I will try to post a link to a Youtube video showing one of these pushers in flight. I think you would love to see it.

I was unable to attach a picture to this post. I will do some research to see if I can learn how to do it. Sorry about that. The Img icon in the tool bar did not work for me as it merely inserted those letters into the text that I wrote.

[calgoddard]

See my previous post describing a Wright Stuff pusher.

Here is a link to a video showing parts of two flights of a Wright Stuff pusher:

https://www.youtube.com/watch?v=WgkJE-gbudc

In the video, the pusher is being flown in a Cat IV fling site (135 feet to the highest flyable height). The model was launched at very high torque in an attempt to gain maximum altitude. I believe this resulted in the tight spiral climb shown in the YoutTube video. It appears that the person taking the video incorrectly states that torque causes the plane to fly in a wider circle.

In a Cat I flying site, e.g. a typical HS gym with a max flyable height of about 24 feet) this pusher was launched at much lower torque and exhibited the typical long, slow climb that is desired in most Wright Stuff competitions.

The very narrow chord of the wing and stab on the pusher shown in this video were dictated by the 2008 Wright Stuff rules. Longer flight times would have been achieved with a wider chord on both the wing and stab. The 2008 Wright Stuff rules also put maximum limits on the span of the wing and stab, as has always been the case in this event, as far as I know.

[klastyioer]

can someone explain a pusher plane like the basics of it cause i have no idea what ill do if its a dime bonus or a pusher plane
i only had size and mass limitations to work w in the past 3 years

[bernard]

can someone explain a pusher plane like the basics of it cause i have no idea what ill do if its a dime bonus or a pusher plane
i only had size and mass limitations to work w in the past 3 years

In previous years, a pusher plane was defined as one with the propeller behind the wing.

[jander14indoor]

Pushers, canards, and even this years tandems are just ways to get student's thinking about unconventional design approaches.
Dime bonus was just added mass, didn't even drive much in the way of design change, just forced students to demonstrate THEY knew how to adapt their plane since it was a 'surprise' factor on the day of competition.
For all of these variations, once you get the basic lift/stability set up, matching prop to rubber remains the KEY issue that drives need to test extensively.

I've said it before, and I'll say it again.

If you are already at competitive times for Nationals, relax, enjoy your summer. Maybe try an AMA class like Limited Penny Plane, or really challenge yourself and move into EZB or F1D.

If you aren't at competitive times for Nationals, pick the rules from any year and practice/test until you get there.

Once you can compete at high level, frankly, I don't think there is anything we can do with the rules that you can't figure out quickly and then spend time optimizing.

Jeff Anderson
Livonia, MI

[klastyioer]

jeff,
do you think itd be better for me to try mini sticks or pennyplanes over the summer
we got 11th at nats and i think im ready to try something different

[coachchuckaahs]

As Jeff said, build to any rules, and work to perfect your craft.

My kids did LPP. these were similar enough to SO planes that no new techniques were used, except we changed to thinned Duco. the motor stick took some testing samples from various sheets, but we found good motor sticks from a 6# sheet.. The props need decent C-grain wood, which is currently a bit hard to find, but you can get it. We used Sig (they had a fire though), and had 7+ pound wood, but still made min weight.

The construction is not that different from FFM kits.

Coach Chuck

[jander14indoor]

Whatever trips your trigger.
Limited Penny Plane is a typical next step. Very doable with hobby shop wood if you select carefully. Capable of very impressive performance without being too fragile. Frankly I'd suggest you start here.

Mini-sticks are several steps harder to hit min weight, but can be built with hobby shop wood. Can be tricky to trim, they tend to have poor launch behavior,

Frankly, if you want a real challenge, but very doable, consider the Hobby Shopper EZB on Indoor News and Views. Detailed build article with a WEALTH of hints and tips on building light but strong. You can build a 700 to 1000 mg plane, yes milligrams with a wingspan of 18 inches, capable of 20+ minutes flight at a big site. If you can build one of these, there isn't anything you can't build.

Jeff Anderson
Livonia, MI

[builderguy135]

Whatever trips your trigger.
Limited Penny Plane is a typical next step. Very doable with hobby shop wood if you select carefully. Capable of very impressive performance without being too fragile. Frankly I'd suggest you start here.

Mini-sticks are several steps harder to hit min weight, but can be built with hobby shop wood. Can be tricky to trim, they tend to have poor launch behavior,

Frankly, if you want a real challenge, but very doable, consider the Hobby Shopper EZB on Indoor News and Views. Detailed build article with a WEALTH of hints and tips on building light but strong. You can build a 700 to 1000 mg plane, yes milligrams with a wingspan of 18 inches, capable of 20+ minutes flight at a big site. If you can build one of these, there isn't anything you can't build.

Jeff Anderson
Livonia, MI

Do you have any suggestions for LPP designs I could find online (hpa maybe?) that are easier to build?