Wright Stuff B

[JasperKota]

Thanks for the informative responses. It was interesting to see their other video, assuming it was their first official flight or a trim flight at regionals, where they had 45ish seconds due to crashing into obstructions, then learn from that, and end up with a fantastic winning flight.

Good luck to those who are competing at states this weekend or the next!

[freed2003]

What time do I need to mdeal at socal? So far my best is only 105 seconds

[jgrischow1]

So our kids' plane was consistently doing around 1:10-1:20. Not spectacular, but competitive enough to get 3rd in our Region. We practiced a few times afterwards in a room with a higher ceiling in anticipation of States and were getting similar times. Fast forward to State on Saturday and nothing worked. Plane either stalled or didn't climb and went into the ground. The kids adjusted the CG and the incidence and the same thing kept happening. Stall, adjust, fly into ground, adjust, stall, etc. Again, this is on the same plane that was flying level and stable two weeks prior. Any ideas what happened?

Plane is FF model from 2016 adjusted for this year's rules, so chords are a little shorter than they could have been. Clocked in around 7.51-7.54 grams. Used Ikara prop trimmed to dia with no pitch adjustments. Using .081-.094 rubber as close to 1.5 g as possible. Winds near breaking close to 1200.

[wlsguy]

So our kids' plane was consistently doing around 1:10-1:20. Not spectacular, but competitive enough to get 3rd in our Region. We practiced a few times afterwards in a room with a higher ceiling in anticipation of States and were getting similar times. Fast forward to State on Saturday and nothing worked. Plane either stalled or didn't climb and went into the ground. The kids adjusted the CG and the incidence and the same thing kept happening. Stall, adjust, fly into ground, adjust, stall, etc. Again, this is on the same plane that was flying level and stable two weeks prior. Any ideas what happened?

Plane is FF model from 2016 adjusted for this year's rules, so chords are a little shorter than they could have been. Clocked in around 7.51-7.54 grams. Used Ikara prop trimmed to dia with no pitch adjustments. Using .081-.094 rubber as close to 1.5 g as possible. Winds near breaking close to 1200.

Was this at Ohio State? I watched much of the day and several teams added winds (and torque) to try and reach the 48' ceiling. In some cases the torque was too much and the motor stick was bending and caused flights to fly into the ground. I'm not sure if this was your flights but it seems to be a common problem when flying in high sites.

[jgrischow1]

So our kids' plane was consistently doing around 1:10-1:20. Not spectacular, but competitive enough to get 3rd in our Region. We practiced a few times afterwards in a room with a higher ceiling in anticipation of States and were getting similar times. Fast forward to State on Saturday and nothing worked. Plane either stalled or didn't climb and went into the ground. The kids adjusted the CG and the incidence and the same thing kept happening. Stall, adjust, fly into ground, adjust, stall, etc. Again, this is on the same plane that was flying level and stable two weeks prior. Any ideas what happened?

Plane is FF model from 2016 adjusted for this year's rules, so chords are a little shorter than they could have been. Clocked in around 7.51-7.54 grams. Used Ikara prop trimmed to dia with no pitch adjustments. Using .081-.094 rubber as close to 1.5 g as possible. Winds near breaking close to 1200.

Was this at Ohio State? I watched much of the day and several teams added winds (and torque) to try and reach the 48' ceiling. In some cases the torque was too much and the motor stick was bending and caused flights to fly into the ground. I'm not sure if this was your flights but it seems to be a common problem when flying in high sites.

Yes. Possibly, but I don't think so because on Sunday I went back to our gym and tried flying with 300-1000 winds and was getting similar issues.

[wlsguy]

We have also had the some problem when something was damaged on the plane.
Last time it occurred to us, the prop was split between the center spars and the plastic film surface. A little glue fixed the issue. If you are sure the motor stick isn't bending, look the plane over carefully and inspect for damage.

[Raleway]

So our kids' plane was consistently doing around 1:10-1:20. Not spectacular, but competitive enough to get 3rd in our Region. We practiced a few times afterwards in a room with a higher ceiling in anticipation of States and were getting similar times. Fast forward to State on Saturday and nothing worked. Plane either stalled or didn't climb and went into the ground. The kids adjusted the CG and the incidence and the same thing kept happening. Stall, adjust, fly into ground, adjust, stall, etc. Again, this is on the same plane that was flying level and stable two weeks prior. Any ideas what happened?

Plane is FF model from 2016 adjusted for this year's rules, so chords are a little shorter than they could have been. Clocked in around 7.51-7.54 grams. Used Ikara prop trimmed to dia with no pitch adjustments. Using .081-.094 rubber as close to 1.5 g as possible. Winds near breaking close to 1200.

I don't have the Div B rules on me but I remember the last time I did this event the mass minimum was around 2.5 w/o rubber? Cutting your mass down is the best way to do it, and CURRENT FFM models will do that, and excessively so. Clay should really make the plane legal as that will allow you to balance the forces. In addition, allowing yourself to put on more mass with clay near the center of gravity will help balance and stabilize the plane. If the plane stalls, then you should check the angle of attack of the wings, as well as the angle at which the propellers are attached. Giving a slight push to help start the plane in the beginning may also help a bit but it should be able to move without your prompting. Also as a word of caution, I have broken about 10 planes by going super high... many places have girders in the ceilings and trusses- safe and not sorry here will save your plane and placement. Lastly, any piece of wood is susceptible to humidity unfortunately and that will help warp the wood. Keeping the plane in a box with low humidity will help the plane immensely (or even a substance to keep absorb vapor in the air) definitely helps prevent warping.

[Raleway]

Just quickly adding on for other Div B teams, some of my friends from other places are trying out a dual motor stick strategy in which you have two light dowels around 3/16 each separate by maybe an inch as the motor stick. This allows for you to take in many more winds- I forgot rule of thumb but on helicopters, the theoretical limit for 0.094 rubber was 153 winds (15:1) at 40 or so centimeters? I'll check those numbers but Wright Stuff is a much longer motor stick, which gives potential for more winds but also has less resistance to tension from the motor stick thus warping is a huge problem but the dual motor stick negates it. I've heard of incredible times from those people so def worth a try (some might even try to truss it to increase resistance haha)

[wlsguy]

It sounds like many teams may be using relatively thick motors. Our team used a motor less than .0625 with something around 3000 winds with the 15 cm ikara prop. We didn't experience any motor stick bending until we flew in the 48' ceiling without back off.
Just thought this might help some teams

[jander14indoor]

Flexing motor sticks due to increased torque typically cause a dive to the floor until torque burns off, then normal flight, NOT a stall. Which kind of sounds like what you have, but it should go away if you reduce the launch torque.

As someone else already mentioned, look for something broken or unexpectedly changed that messes up trim that you've missed.

Unless you are talking about a power stall, which should only occur once. It can be recognized by the plane launching hard the nose pitching up until it almost hangs on the prop, then a dive to the floor. You fix that by increasing the down angle on the prop.

There are several ways to prevent bending motor sticks.
- Bracing with threads, typically kevlar or tungsten wires.
- Bracing with Carbon Fiber glued to top side (tough to do without excess weight gain, but possible)
- Hollow motor stick, either round or rectangular cross section
- Use good VERY light wood of a much larger than expected cross section. Has similar effect as hollow motor stick of moving material away from the neutral axis.

One way to test for bending motor sticks in a LOW ceiling site is partial motors. You can learn more about this technique by searching this year and past year strings.

Jeff Anderson
Livonia, MI