Wright Stuff B

[fmtiger124]

whoa we used to have whole sub forums for each event???

[StampingKid]

Speaking of things becoming more relevant on rereading:

If you build a decent sized fin or tip plates on the stabilizer, you should have enough roll stability. If you have massive propellers, and roll becomes a major issue, some people like to offset the wing, so more wing area is over the left side of the plane and actually gets lift because of the rolling force.

This past spring, I was having problems with countering roll on the initial thrust. I had an offset wing. I had not thought about increasing the size of the tip plates on the stabilizer but from this it appears to be one more thing to try as I was not having too much luck with unwinding and wound up launching at an angle.

[Dark Sabre]

whoa we used to have whole sub forums for each event???

No, only ever for Wright Stuff and Mission Possible, both of which are going to be around next year, and both of always garner a lot of attention and have a lot of different aspects to discuss...so you can expect to see couple separate forums back again.

[fmtiger124]

whoa we used to have whole sub forums for each event???

No, only ever for Wright Stuff and Mission Possible, both of which are going to be around next year, and both of always garner a lot of attention and have a lot of different aspects to discuss...so you can expect to see couple separate forums back again.

ah...ok so we're going to have a ws and MP seperate forums?

[karatekid44]

that would be helpful

[GitItWright]

Roll Issue- Wright Stuff

StampingKid-

There are a few reasons why the roll happens and carneyF1d covered some of these.

For lack of and engineer's techno speak, it pretty much boils down to countering a "mechanical" issue with an "aerodynamic" fix.

The roll begins with Newton's Third law, for every action there's an equal and opposite reaction. On launch the airplane is reacting first to the high torque of the motor pushing the airplane in the opposite direction that the prop is spinning. Much could be due to the high torque being transmitted through the motorstick and twisting it along its axis. This causes multiple and "infinitely" changing variables to the flying surfaces.

Most notable is that the left and right wings twist in opposite directions. Try it and see the difference yourself. Set up an airplane and twist the nose left and the aft end right. If the left wing's leading edge is lower than the trailing edge, that wing reduces lift. If the right is opposite, with the leading edge higher than the trailing edge, then it has more lift. This whole combination will cause the airplane to roll left (counter-clockwise looking from the tail forward) and even dive.

The aerodynamic fixes- can include the following-
1) Break and raise the left wing's leading edge for more incidence (higher angle of attack) in comparison to the left trailing edge. re-glue the new setting
This, aerodymanically, increases lift to counter the mechanical forces of the high torque motor.
2) Offset the wing to the left so that more wing area is left of the centerline (the motorstick in this case) usually this is a built-in feature of locating the wing posts so that the wing is offset.
3) Confirm the twist in the motorstick and build a stiffer one. This issue was covered thoroughly during the season and probably showed up as a "bowing motorsticks" thread.
4) If the airplane is overweight (ie: 8 grams or more), it takes larger motors and even more torque effecting the motorstick twist. Keep the airplane light but make sure the motorstick is a reasonale cross section 1/4 x 3/8 is a good starting airplane weight close to 7 grams.

Good Luck

[carneyf1d]

Anybody know when the draft rules come out?

[fmtiger124]

Anybody know when the draft rules come out?

not for a while id guess

[smartkid222]

i don't think they are going to have draft rules this year. They posted the tentative event names and i think the actual rules coming out in september are next.

Carney, i think you posted a link before to show us a helicopter, but it linked to an album and i didn't see any helicopters there. Do you (or anyone) have a picture of a helicopter discussed in the flight trio thread?

[blue cobra]

jander14indoor,

Many, many posts back, I think on page 24, you mentioned using 8# balsa for wing posts. Is this really dense enough? Especially with hot and humid conditions often present in the gym.