Hurricane 550 question on your thoughts here

[misskimo]

I have this little heli on its way to me , a fellow showed me this picture of the servo linkage layout, I was thinking this was all wrong , push pull would be affected, as you can see , round wheel , balls not 180 from each other and down the center line where the horn bolt is ,
what do yall think?

[ozace]

Tony, best to wait until you have the heli in your hands, then you can see why it is the way shown in the diagram.

[Impact]

Here are a few links that may help explain.......Impact

See page two, it's for a pull/pull rudder on a plane but the geometry is the same.
http://www.modelaircraft.org/Mag/hurley/pdf/pullpull.pdf

This info on
PULL/PULL CABLES found here http://findarticles.com/p/articles/mi_qa3819/is_200202/ai_n9048077

A great way to save weight in the tail of an aircraft is to replace those heavy pushrods with pull/pull cables. This is frequently done for rudder control and is often done for all tail-control surfaces in scale WW I and early vintage airplanes. If it's to operate properly, the geometry of the cable control system must be balanced to ensure and provide equal travel in both directions. As in full-size aircraft, a model's pull/pull cable setup is a closed circuit and to maintain proper control, the entire system must remain taut. The cables will slacken if the servo-arm or tiller arm and the control-horn throws are not equal. When a control surface is deflected away from neutral, one side of the cable feeds more than the other side pulls and this can lead to unwanted flutter; by equalizing tension on both sides of the cable control system, you keep the control-surface movement very stiff.
One way to keep the tension equal is to keep the control-horn attachment points for the cables directly in line with the hinge centerline. If this is not possible, such as is often the case with a scale model aircraft, you can maintain the tension by making the tiller's arm geometry the same as the control horn's layout. If the hinge line at the control horn is 1/4 inch in front of the horn attachment points, make sure the tiller-arm pivot point is also 1/4-inch in front of the cable attachments. Either way, it is the geometry of the two connected control input arms that makes the difference (see illustrations).

And this one should sum it up,happy reading.....Impact
http://members.cox.net/bdfelice/Ackerman/ackerman.htm

[misskimo]

hey , thanks for that last one , but man its a small% of getting it completely perfic huh?. but its got to be done that way because of the double bell crank, well unless you use just one control rod instead

[ozace]

That last one is a great read with pretty pictures.

[ArtPiranha]

One more pic from me!
http://b0.imgsrc.ru/p/piranha/2440725aWR.jpg

[misskimo]

yeh! one of the things that limits its ability is , cant use but half the servo travel , like on my Ion , I can go to 80% on my swash with those big arms , which I run around 60 to 65% anyway

[Lynxman]

To see how long your links need to be and where the holes need to be drilled measure the distance from the center of the bellcrank screw to the center of the servo screw.

[Wheelhaus]

what a strange layout. it's still parallel and blah blah so it won't bind, but why?

[Fred Bronk]

what a strange layout. it's still parallel and blah blah so it won't bind, but why?

Perhaps under the Swash it may bind at full cyclic/pitch. That geometry would offset that by moving the link away from the center at full throw.

FB

[bmaaa]

Hello,

Will this pinion (http://www.readyheli.com/11T_RevCo_H..._p/ho-4011.htm) work with the Hurricane 550:



In other word, is a "1.0 mod" pinion OK ?

many thanks

[RJ]

Hello,

Will this pinion (http://www.readyheli.com/11T_RevCo_H..._p/ho-4011.htm) work with the Hurricane 550:



In other word, is a "1.0 mod" pinion OK ?

many thanks

Tom Viper says its mod 0.8 here:
http://www.rcgroups.com/forums/showpost.php?p=7379930&postcount=888

[RJ]

misskimo,

I made a drill guide from aluminum on my mill, but after doing so, I think it would be easier to use an extra bellcrank as a drill guide for the servo wheel. BTW, I don't think the printed drill guide in the instructions is accurate.

Regards,
Rick

[bmaaa]

1 - has someone already tested the GAUI's torque tube upgrade ?

is there a real increase in flying time (less friction) ? From where is it already available for sale ?

2 - Hello,

I am also going to go FlybarLess on my Hurricane 550.

2 questions:

- Does a flybarLess system need STRONGER servos. I am indeed wondering if the Futaba S9650 Mini-servos (30 grammes, usualy recommended for the Hurricane 550) will be OK also with a flybarLess system or if I need in this case some stronger servos ?


- I think that I will instead go for the Robbe Helicommand RIGID system. It seems to be also able to provide some "auto-stability/auto-pilot " that the other electronic flybar systems don't ? Is it right ?

thanks