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HIROBO Freya - Sceadu - Shuttle > Radius block alignment - The easier way
 
 
Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

Bumping this up front. Very simple effective method of alignment. Thanks Lior. On a side note. My EVO is ready to go, finally! All we need is some weather.
03-13-2005 Over year old.
 
 
TMoore
rrProfessor
Location: Cookeville, TN

Al,

I just put the CX dampners in mine and they work great. Nice improvement that won't cost any hover stability.

TM
03-13-2005 Over year old.
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Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

I put them in also.
03-13-2005 Over year old.
 
 
davehour
Key Veteran
Location: Guayama, Puerto Rico

Ok, so you prefer doing it aligning the outer and inner balls and then check if there is interaction, or by putting the flybar at 90 degrees from the boom, then checking for interaction?

David
03-14-2005 Over year old.
 
 
I3DM
rrProfessor
Location: Israel

Dave, read what you wrote again - both methods are exactly identical !

anyway, it doesnt really matter how you do it, i like the flybar in 90 degrees to the boom although its not necessary - just because it is going to be the easiest to watch for paddle interaction when the flybar is at exactly 90 degrees to the boom.

Team pilot for Radix, Helidirect, Logictech, ThunderPower, Fromeco, Gaui
www.liorzahavi.com
03-14-2005 Over year old.
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davehour
Key Veteran
Location: Guayama, Puerto Rico

Yes, I know, but as you pointed out, I wanted to know which one seems to work easier .

I assume you eyeball the flybar at 90 degrees with the boom.

Thanks.

David
03-14-2005 Over year old.
 
 
I3DM
rrProfessor
Location: Israel

That is correct, it is quite easy, i didnt call it "the easier way" for nothing !!

Team pilot for Radix, Helidirect, Logictech, ThunderPower, Fromeco, Gaui
www.liorzahavi.com
03-14-2005 Over year old.
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I3DM
rrProfessor
Location: Israel

Just a quick bump for an old post that could still help a lot of people.


Team pilot for Radix, Helidirect, Logictech, ThunderPower, Fromeco, Gaui
www.liorzahavi.com
05-08-2006 Over year old.
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Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

Should be made a "sticky" up front in the Hirobo Section.
05-08-2006 Over year old.
 
 
rdalcanto
Key Veteran
Location: Salt Lake City, UT

Except that it won't give you axial rolls, because it won't take the lag of the blades into account. This post should not be made a sticky, but deleted.
Here is the thread you want:
http://runryder.com/helicopter/t244...ghlight=phasing

Rick

Team MRC & Magnum Fuels
05-09-2006 Over year old.
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Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

Sorry RD. Nothing ground breaking in your discovery. Nothing ground breaking here either. "Once the heli is setup correctly, a trick for pretty rolls is to lower the collective in FFF to about +3 before starting your roll. Then smoothly go to about -3 when inverted, and back to +3 as you come right side up again. You want small collective changes around zero." Been around for as long as negative pitch has. I'll stick with the no inter-action method, and be happy, thanks.
05-09-2006 Over year old.
 
 
rdalcanto
Key Veteran
Location: Salt Lake City, UT

Quote 
I'll stick with the no inter-action method, and be happy,


You don't get it. The no interaction method doesn't take the lag of the blades into account. Go back and read the thread I pointed out. Augusto explains it very well. The small collective change tip is unrelated, and just thrown in there for beginners (they all use too much).

Rick

Team MRC & Magnum Fuels
05-09-2006 Over year old.
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CK_
Senior Heliman
Location: Redondo Beach, CA

Setting the phasing exactly at 90 degrees isn't necessarily the right answer but it is a starting point. Like Augusto and Rick said, blade lead/lag can cause a phase error.

If the head has individual flapping hinges for the blades like the old concept 30 or nexus heads then that also introduces a phase error due to a centrifugal force spring effect that changes the natural flapping frequency of the blade. Without a flapping hinge offset, the flapping frequency exactly matches the rotational frequency. A blade that is flapping at the same frequency that it is rotating can be seen as a tilting rotor disk.

Another source of phase error is aerodynamic cross coupling. When the heli rolls, one side of the disk is flapping down into the wind, increasing the lift, and one side is flapping up into the wind, decreasing lift. A left/right lift imbalance on the rotor causes a reaction fore/aft causing a corkscrew. This effect increases as roll rate increases and rpm decreases.

You can read Stephen Bell's article on the subject HERE

As long as these things have one main and one tail rotor, they will never fly perfectly straight or roll perfectly axially. That's part of the fun of flying them.

Chris

EDIT: You can observe the aerodynamic cross coupling directly by removing the main blades and spooling up to a decent rpm. Push the cyclic fore and aft very slowly and the flybar disk will pretty much deflect purely fore and aft. If you move the stick fore and aft quickly, you will see the flybar deflect sideways when it goes fore and aft. This is aerodynamic cross coupling of the flybar.
05-09-2006 Over year old.
 
 
Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

I do get it,thanks. Your method requires automatic phase correction, depending on how fast you push the sticks. You also assume a fixed phase helicopter can't /doesn't fly as well as one with adjustable phasing.If it works for you, great, but your method is just as flawed as the I3DM method above. Both will get it flying well enough to realize it's the guy on the sticks that needs the work, not the machine.
05-09-2006 Over year old.
 
 
I3DM
rrProfessor
Location: Israel

Quote 
Both will get it flying well enough to realize it's the guy on the sticks that needs the work, not the machine


Thats exactly my point, but my method takes 30 seconds to setup, while other methods take much more, and for us, 3D pilots, its workign beautifully.

rdalcanto, i would not say this post should be deleted - at least due to all the happy RR members who like my method.

Team pilot for Radix, Helidirect, Logictech, ThunderPower, Fromeco, Gaui
www.liorzahavi.com
05-09-2006 Over year old.
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Jafa
Elite Veteran
Location: Sydney, Australia

I've found this topic interesting and informative
But I do agree with I3DM - the post is useful
There have been several times when I've been asked
to check over a heli (new or rebuilt)
and found the phasing to be wrong (using this method)
despite the owner putting a lot of time and effort
into the setup at home.
And I have certainly found that all heli's that
I've used this technique on fly just fine.
It's a fast way to get right into the zone.

But I am now also interested in experimenting with phasing,
so thanks for your input guys...


Lepton | TRex600Nitro | Sceadu | Freya | Avant | Predator Carbon Max
05-09-2006 Over year old.
 
 
rdalcanto
Key Veteran
Location: Salt Lake City, UT

Lior,
You are an incredible pilot, but less talented 3D pilots like myself, prefer a heli that rolls perfectly without having to use elevator correction. The only way to achieve that with a mechanical setup is to have a nose heavy helicopter, which will cause other unwanted flying tendencies. Yes, your method is easy to setup on the bench. However, actually adjusting the phasing for a perfectly flying helicopter doesn't take much time either if you make a fine mark on the radius block and move it counter-clockwise a little at a time, and pay attention to what happens to the rolls as the tank empties. I just hate to see less talented pilots than you use your method, and then struggle with corkscrew rolls and blame the heli.

Sorry if I was too harsh the first time. I just hate to see the same stuff re-hashed on the forums, especially when it could be more accurate. If a pure mechanical setup was best, Hirobo would have integrated the radius block pins into the hub, and Augusto would have made a simpler/cheaper design for his head....

Rick

Team MRC & Magnum Fuels
05-09-2006 Over year old.
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I3DM
rrProfessor
Location: Israel

Rick - thanks for the reply, and for the compliments.

just a note, every phasing adjustment method is only the first step, you have to adjust each machine little at a time until you get to the sweet spot.

i might be lucky, but when i used this method - all my helis rolled perfectly. they all have perfect CG as well BTW, i dont fly anything nose heavy.

It seems we're all in the same boat here, your opinion is 100% right.

Team pilot for Radix, Helidirect, Logictech, ThunderPower, Fromeco, Gaui
www.liorzahavi.com
05-09-2006 Over year old.
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Al Magaloff
rrMaster
Location: 12,199 Posts- Enough Time Wasted. See Ya!

Agree with both of you. Both methods will get the phasing somewhere close. Lior's method needs to be done on the bench, first. Then go fly and tune for your particular likes/dislikes. How do your rolls look from the end?
05-09-2006 Over year old.
 
 
Kona Chopper
Veteran
Location: Kailua-Kona, Hawaii USA

Good write up I3DM. I adjusted the radius block like how you exlain and now I am getting nice rolls. Before they looked they looked funny. Prior I thought it was just my thumbs, but, I had a friend watch my thumbs while I did rolls and he said they were where they should be. After adjusting the block alls good.



got fuel??
04-10-2007 Over year old.
 
 
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HIROBO Freya - Sceadu - Shuttle > Radius block alignment - The easier way
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