What software are you guy's using?

[Mithrandir]

Been brainstorming ways to reduce/eliminate the inertia from moving two servos.... here are a couple ideas... each has its own set of issues... a couple vids show failure mode with one servo locked up....
http://www.giantcircus.com/Videos/Ru...-02-run-03.mpg
http://www.giantcircus.com/Videos/Ru...s/broke-20.mpg
http://www.giantcircus.com/Videos/Ru...e_servo-01.mpg
http://www.giantcircus.com/Videos/Ru.../direct-01.mpg
http://www.giantcircus.com/Videos/Ru...oke-20-deg.mpg

both systems feature 120 degree servo throw.
the big grey bellcrank is the rudder tillar arm

[esc]

Aw Spooky, that's a shame! In truth there are not that many crashes where the plane cannot be repaired and most of the damage to your plane seems to be at the nose end. It looks like the pilot got out alright :-)

I too have a Spektrum DX7 and seven flying models at the moment with a mixture of AR6100E's, AR6200, AR6100 and one AR500 receivers. On the bigger models and helicopters, or ones with more than four micro servos, I always run the radio at 6 volts from a CC 10A BEC. I have never experienced any problems at all with my radio. Have you found a reason for the lock out you experienced?

How soon do you think she will be airborne again?

Good luck all.

Dave

[Spooky]

Mithrandir, looks like you just about have it figured out, nice work.

	Quote:
	It looks like the pilot got out alright :-)

LOL, yeah, he bailed. Still not sure exactly what or why it happened, but she'll be back.

Thanks guys,
Dean

[mxwrench]

Pro/E wildfire 3.0 (gonna be 4.0 starting monday) at work. Pro/E wildfire(student edition) and Bobcad V21/Mach2-Mach3 at home.

[esc]

Just finishing off the 2-D drawing and completing the annotation. Hopefully, if I get the chance I will finish it this week.

Regards all,

Dave

[rcpilot82]

Looks Light. are the ailerons to be cut from one solid sheet or built using "stick" construction?

[Mithrandir]

it has been my experiance that planes with thick, blunt & round leading edges on the wings don't harrier very well....

Why are you using an airfoil that is such a Fatty?

[rcpilot82]

I have a few skeeters with an airfoil like that. they don't do high alpha worth a crap. but are still fun planes. The hobby lobby reflex nailed the airfoil in my opinion.

[esc]

Hi guy's,

When the drawings are finished the ailerons will be shown to be constructed of balsa strip and fillets. I will probably re-model them anyway as I created them as a one piece extrusion for expediency sake. At the moment the drawing does not reflect the real construction. I may create them in pieces or fake it on the 2-D drawing.

The wing section is typical of those used by Precision Aerobatics for their "Electric Shock" and several other planes I can think of. You are right that a blunt aerofoil section has some pecularities but it also generates lots of lift for slow speed maneuvres. All aerofoil sections are a compromise and this may not be the best one in the end. If the prototype does not perform as well as it might I will adjust it or re-design the wing if necessary.

One other thing blunt sections tend to do is tip stall (that can be compensated for with the wing tip design) and this may be what caused your harrier problems. My wingtips will change before I let rcpilot82 have the drawings.

Thank you for your comments, keep them coming.

Dave

[Wojcigitty]

Ever flown a PA Addiction? Thick wing, rock-solid harriers if you get the angle right.

YouTube - Cody - Freestyle RC

There is more to it than the thickness of the airfoil. The depth of stall, angle of attack, aspect ratio, and CG are all big players. I agree though, I have flown many fun-fly planes that absolutely sucked in a harrier. You might try increasing the chord and decreasing the span to improve harrier performance.

[Mithrandir]

the max Cl of a thick section is not much more then a thin section...
the thin section... or more specifically... the sharper leading edge causes a more
distinct and abrupt seperation then a blunt leading edge... so in the instance of a harrier... the top of the wing seperates, and stays seperated.... the blunt leading edge has a stall line that meanders across the cord of the airfoil so the lift also changes.... and it is this action that combines with wing rock to cause more wing rock....

at least this is what was 'splained to me by Hanno Prettner at the St. Louis Huckfest in 1994

[esc]

Nice flying Wojcigitty.

No I haven't got one of those but I have an electric shock. The Addiction is on my list of planes to build sometime in the future :-)

Note the wing tips - I think they may help to prevent tip stalling and I am contemplating changing my design to something similar.

Truth is someone has to build my plane to find out if it flies well or not, everything else is just speculation. it's not etched in stone yet and given enough reason I will change it.

Dave