RunRyder - Synergy bellcrank geometry?

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Synergy R/C Synergy N9 > Synergy bellcrank geometry?

RappyTappy
Elite Veteran
Location: Las Vegas, NV

I was just checking out the Synergy pictures. If you look at the aileron bellcranks, note the distances from the pivot point:
-ball link that goes to the servo
-ball link that goes to the swashplate.

I would think that the servo would be working harder than it has to because of the mechanical disadvantage. Maybe it may not be that big of a deal, but a good discussion would be nice.

Chris
Xero G

Forever Brothers
Mickey Tylo

01-17-2006 Over year old.

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bigblock
Senior Heliman
Location: sweden

I dont think the servos are working any harder in this setup.
Actually , I think JK/TB designed it this way to make the 3 servos
fit in a narrow canopy, by using smaller servo wheels.

01-17-2006 Over year old.

spaceman spiff
Key Veteran
Location: Tucson

Maybe he was going for speed?

That set up will put more stress on the servo.

01-17-2006 Over year old.

Chem Geek
Senior Heliman
Location: Sarasota, FL

While you need more force at the bell crank to move the swash with that setup, it also means you need less distance to be traversed at the servo and can use small wheels like bigblock said. It's the same as using huge wheels at the servo and swapping the sides of the bell crank so that the servo connection is the one with the huge leverage.

01-17-2006 Over year old.

RappyTappy
Elite Veteran
Location: Las Vegas, NV

Is the load the servo feels more than that of say one with a large wheel and bigger input arm on the bellcrank than the output arm?

Chris
Xero G

Forever Brothers
Mickey Tylo

01-17-2006 Over year old.

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Thuvanduc
Senior Heliman
Location: Salt Lake City, Utah

JK/TB designed arms configuration this way to minimize the amount of interaction due to ECCPM. Because the servo(swashplate) travel is not linear in ECCPM setup like mechanical mixing; therefore, interaction happens at the further end of the servo travel range. By minimizing the travel at the servo arm with the setup they have in the Synergy, will minimize or eliminate the interactions, or in another word bring the swash plate travel closer to linear.

The torque is just matter of servo selection!

Duc

01-17-2006 Over year old.

RappyTappy
Elite Veteran
Location: Las Vegas, NV

sweet! Thanks, now I see said the blind man

very interesting!

Chris
Xero G

Forever Brothers
Mickey Tylo

01-17-2006 Over year old.

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ChristianM
Veteran
Location: Oslo, Norway

Thuvanduc is right but a setup like that will also be more sensitive to any slop that develops in the control system. That probably why they have beefed up the push rods to eliminate any flexing. Just watch the ball links for any wear and of course use high quality servos (goes without saying really in this heli).

Christian

Burn fuel, be happy

01-24-2006 Over year old.

sp1nm0nkey
Senior Heliman
Location: Redwood City, CA

Well, if the swash moves up and down the same ammount as any other heli, than the servos aren't working any harder. It's the end result that matters.

However, that setup puts a lot more strain on the ball links.

01-24-2006 Over year old.

blade3d
Elite Veteran
Location: New Jersey

From: rupert gillette [mailto:regill00@optonline.net]
Sent: Tuesday, December 27, 2005 5:46 AM
To: synergy@synergyhelicopters.com
Subject: Re: synergny 9

Are the side frames 2mm or 3mm and on the eccpm arms I see the leverage is on the servo and not the bell crank by your design can the servos handle the stress ??

thanks

Rupert
---------------------------------------------------------------------

Rupert,

With all the testing we have done the servos seem to be fine.

---------------------------------------------------------------------

I asked the same question this was their reply

Blade3d

01-24-2006 Over year old.

carcrasher
Key Veteran
Location: east coast

side frames

So are they 2 or 3mm?

01-24-2006 Over year old.

blade3d
Elite Veteran
Location: New Jersey

That question was not answered it looks like 3 to me .

Blade3d

01-24-2006 Over year old.

sp1nm0nkey
Senior Heliman
Location: Redwood City, CA

Quote
that set up will make slow strong servos speed up on cyclics controls.

Not necessarily. It's the same ratio as the MA machines since the distance from the bellcrank pivot to the servo link ball is the same as the distance from the servo's center to the ball on the servo.

I just noticed that the servo arm is not in the same plane as the bellcrank on the synergy

. That's gonna create some control interaction.

01-24-2006 Over year old.

sp1nm0nkey
Senior Heliman
Location: Redwood City, CA

No, not quite either. See, on the Synergy, the distance from the center of the bellcrank to the servo ball is shorter, but the distance from the center of the servo to the servo ball is also shorter. It's the exact same ratio.

Here's a diagram:

01-25-2006 Over year old.

sp1nm0nkey
Senior Heliman
Location: Redwood City, CA

look, a fat guy on a seesaw will make a little guy on a seesaw fly just as far if the ratio of the length of one side to the length of the other side is kept equal. By decreasing the distance from the center of the bellcrank to the servo ball on the bellcrank, you're now decreasing the ratio, so to make it equal, you decrease the ratio from the center of the control horn on the servo to the ball on the servo's control horn. The length of the center of the bellcrank to the swash control ball is the same as the length of the length of the bellcrank to the swash control ball on the Fury/Tempest/Stratus.

If the ball on the control horn was moved OUT, or if the ball on the ball link linked to the ball on the servo control horn was moved IN, then it'd be a different ratio and would speed up and load the servo.

HOWEVER. Since the ball on the control horn is moved IN and the ball link linked to the ball on the servo control horn is moved IN as well and the distance from the pivot is the same, it's the exact same ratio.

It's not that difficult to understand. Would someone PLEASE step in?

01-26-2006 Over year old.

ChristianM
Veteran
Location: Oslo, Norway

sp1nm0nkey is right on the money. If the length of the servo horn is the same as the length on the bellcrank, then the ratio is the same and the load on the servo is the same. However, the load in the pushrod is higher with the shorter servo horn and bellcrank, thus it is important with a heavy duty pushrod and no slop.

Christian

Burn fuel, be happy

01-26-2006 Over year old.

spaceman spiff
Key Veteran
Location: Tucson

Quote
If the length of the servo horn is the same as the length on the bellcrank, then the ratio is the same and the load on the servo is the same.

Touche. Still would have prefered that the belcrank be larger to match up with the longer 4 point or large disk servo arm so you have less side force on the servo bearings.

getting impatient to see this new beast.

02-02-2006 Over year old.

sp1nm0nkey
Senior Heliman
Location: Redwood City, CA

Same here. It also loads the ball links, which is what I'm concerned about. You also have interaction from the wheels not being in the same plane. The whole reason they did this was to clear that canopy. They could've avoided this whole deal by putting the servos into the sideframes. Then you'd have a cheap Fury with a low tail boom. Sweet!

02-02-2006 Over year old.

bathmagic
Senior Heliman
Location: Berwick,Victoria, Australia

synergy

guys guys guys

i sat with jason last weekend and went through all of these things and i can say have a chat with him at a fun fly and ask why certain things are done certain ways.

i think you will certainly impressed at this model

like all they do have the pros and cons

but all in all it is a good thing

its more about being in a price bracket and having something that doesnt need a degree to get to work well

a ferrari is great but who can afford one ?
wouldnt you prefer to ahve something better than a rappy and at the same price bracket ??"

be patient its worth the wait

Dale

3DMP , Vbar 600 "Innovation" The key to success !

02-02-2006 Over year old.

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Thomas L Erb
Veteran
Location: Alliance ohio

Hi all I agree with sp1nm0nkey that the ratio is the same. my question is do you think the longer arm can produce more reverse load to the servo by mechanical advantage under load then the MA bellcrank setup? And if so is it more-less or the same as MA's as far as the load transmitted to the servo itself. Tom

02-08-2006 Over year old.

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Synergy R/C Synergy N9 > Synergy bellcrank geometry?

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