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ZoomsHobbies . HeliHobby . Ron’s HeliProz South

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Synergy R/C Synergy N9 > Synergy bellcrank geometry?
 
 
ChristianM
Veteran
Location: Oslo, Norway

Yes from the servos perspective, a push/pull system will be identical to a servo brace. I do not necessarily agree that it is simpler. A servo brace needs the support frame, the support pin for the servo, extra ball bearing and it needs to cater to different brands of servos. I think the push/pull is a bit simpler but it would not work with the servo layout on the Synergy. Either way it is not a big deal.

Christian

Burn fuel, be happy
02-27-2006 Over year old.
 
 
blade3d
Elite Veteran
Location: New Jersey

I think the future will be servo support less moving parts.

Blade3d
02-27-2006 Over year old.
 
 
HiroboEric
Veteran
Location: Los Angeles, CA.

Isn't that geometry termed D-angle?

Eric Pacheco, AirWorksRC.com
03-08-2006 Over year old.
HOMEPAGE  
 
 
Helinutnz
Elite Veteran
Location: below 42 South

I have seen badly set up push pull with binding at the extremes. The synergy uses huge links and rods along with servo pivot supports and I'd be happy to run them for sure. I would imagine being a ccpm machine that the distance isn't much of an issue on the bellcranks. In this situation I'd imagine that stress on any servo in an HPM machine is greater due to one servo controlling each plane and yet a lot of us put 9252's on elevator and aileron on these machines with great success. Splitting the torque duties between three servos must reduce stress on them and with the servo pivot supports I would imagine the synergy's 9252's that I saw Jason running would be under less stress than a lot of 9252's in freyas.

Anyway I watched him fly it four times down in NZ and it's an impressive machine in my eyes. I'm getting one. Is it going to make me a better pilot...nope....fuel will do that.....does it look cool and have some great features on it....you bet. I can wait for the machine to reach the market as it seems like they aren't rushing to put the heli on the shelves but more like they want it to be right for a successful launch and we'll all be better off for it. Patience is a virtue.
03-08-2006 Over year old.
 
 
Helinutnz
Elite Veteran
Location: below 42 South

help with what? If you have seen a push pull setup with rods not parallel (freya,sceadu) and the balls not positioned correctly then you will notice humming in the servo and the servo moving in the rubber mounts. The result...dead servo sooner.A Well set up the push pull will ease the servo bearing side loads and reduce the chance of links popping off.
A centre mount pivot bearing will transfer side load movement to the pivot bearing and steady the servo and servo wheel. Just a different way of doing the same job.

Haven't seen many links pop off in flight....point in case...freya....push pull to the aileron belcrank and then one link to the aileron. In this case the push pull has no advantage in reducing link loading but never seen one pop off.

In the synergy the servo is centre pivot supported and the links very sturdy and the rods heavy. Just a different way of doing the same job as push pull and equally effective. In fact easier to set up due to location of the ball on the wheel not as critical as positioning two balls correctly for zero binding.

Push pull and centre pivot probably overkill adding complexity,cost and weight. Simple effective setups will be easier to maintain and will probably be bulletproof.
03-08-2006 Over year old.
 
 
sookainian
Senior Heliman
Location: Singapore

well, everyone got their diff point of view =X
03-10-2006 Over year old.
 
 
Helinutnz
Elite Veteran
Location: below 42 South

firstly "bulletproof" is a figure of speech. Take it literally if you like.
Secondly...I didn't say that the push pull will cause a dead servo sooner....do you understand english? Please read my post again properly. I believe it is pretty clear that I am not slagging push pull....I use it on my evo and freya.....as I Stated in my post it needs to be set up correctly or the servo will bind...draw more current and wear out sooner than normal. Without parallel rods as in the evo and freya the angles of the rods change with the movement of the servo. The balls need to be positioned at 90 degrees to the rods on the servo to prevent binding.(simple triginometry) This will mean you can't use an arm but have to select the positions and drill a servo wheel to do this. The x-spec has these details in the manual. I have seen them set up incorrectly and they don't move as freely as mine do when removed from the servo due to binding.

None of my post was slagging either method so why the bull$hit comment? Do what you want...I am no expert. good luck
03-12-2006 Over year old.
 
 
Helinutnz
Elite Veteran
Location: below 42 South

Perhaps you need to take more notice of english at school. You are just looking for an arguement huh?

Simple but effective....read the words and understand them. Effective.....yes that does explain that it is an effective system.
who ever said I was talking about hovering the synergy?

Bullet proof means no maintainence....did you make that up? Do I run my helis without maintainence? Am I advocating that?

You read far too much into things. I think if I were to read into your postings that you are just another aggressive kid looking for a rise out of someone. Again...study my post and understand.....you don't have to be a brain surgeon.
Good luck with it.
03-12-2006 Over year old.
 
 
Dr. Fibinotchi
Key Veteran
Location: Sioux Falls SD

vote.

keep the thread clean. pm instead. Tired of seeing this slinging mud...

All that a man achieves and all that he fails to achieve is the direct result of his own thoughts
03-13-2006 Over year old.
 
 
spaceman spiff
Key Veteran
Location: Tucson

Got to see this heli up close this weekend. Flys great, well truth is JK could make a washing machine fly great, but still... very impressed with how it turned out. Looks like it might be an easy build. The one he was flying still had the larger metal belcrank. Forgot to ask if that was the proportions of the ones in the kit.
03-13-2006 Over year old.
 
 
Helinutnz
Elite Veteran
Location: below 42 South

well be nice then. You commented that you believed half of what I said and the rest was BS. If you don't agree with me then that is your perogative and you are quite within your rights to question anyones ideas but you can do it in a nice way.
If you read my post again you will see I am not against either type of control system but yes I believe both on the same ship are probably overkill given the fact that these machines are punished pretty hard and there are few failures. I am not keen on the servo driving a control rod off one side without support so either a well setup push pull or pivot supported servo would be advisable. I have come from an engineering background so feel reasonably confident in this line of thinking. I welcome discussion from others...thats what the forum is all about.
I have seen the synergys control system and it looks more than robust with huge links,rods and pivot supported servos so I would imagine it will not have any problems.
03-14-2006 Over year old.
 
 
Colibri
Key Veteran
Location: The Netherlands

What about vibration and servo braces. We use rubber with eyelets to protect the servo housing from vibration but what about the brace which mechanically couples the frame to the servo output shaft.

Can this also cause vibration damage? I've read that most helicopters use indirect control of the swash (through links and levers) to protect the servo from the vibration feedback from the rotor, unlike for example some Vario helicopters where here is a direct link from the servo to the swash. If this really is an issue than maybe a servo brace also has this disadvantage where the push pull doesn't.

Just some thoughts, no facts.
03-14-2006 Over year old.
 
 
steve9534
Key Veteran
Location: yakima, wa.

Control systems

The advantages of push-pull controls are the redundancy of having two pushrods and sets of links. I have broken one on a push pull setup and didn't even know until I landed. The other advantages are that, if properly set up, they can be truly slop free, and the pushrods are primarily loaded in tension, which is the way they are the strongest. The disadvantages are that they need to be set up correctly or the servo will be loaded and may wear out sooner, and will definitely draw more current. The setup is definitely more challenging than a single pushrod, but still not all that difficult. Even with a push pull set up, the servo can translate in the mounts with high torque loading, and this can affect control inputs. Whether it's enough to worry about, I doubt it, but a servo brace would help to prevent this unwanted movement. steve.
03-14-2006 Over year old.
 
 
Helinutnz
Elite Veteran
Location: below 42 South

This is an extract from the synergy helicopters site. Quote."The servos are mounted in a composite tray – once again attenuating airframe vibration and extending servo life".


Possibly if servo's are mounted in a carbon frame there is more vibration transmitted where they have used a composite frame for the servos to mitigate the problem somewhat. There is the carbon servo supports and the possiblity of vibes being transmitted through them. If a push pull system was loaded slighlty there may also be the likelihood of vibes being transmitted through the two linkages.
I wonder if the total vibration experienced which is possibly the most through the servos being tightened down to the frame is more damaging than the indirect vibes through the gear train?? Is it the servo's gear train, motor or SMT board we are worried about most? The pivots are mounted to the composite servo mounts so they should move with the mounts I guess.

Good point about the one linkage letting go and hence the added security of push pull. However in the synergy the Rods and links are very heavy duty much more so than most heli's out there so I imagine from and engineering standpoint that the possiblity of a broken link or rod in flight is very very low.
03-14-2006 Over year old.
 
 
Colibri
Key Veteran
Location: The Netherlands

Quote 
The pivots are mounted to the composite servo mounts so they should move with the mounts I guess

I'm not sure that will happen. Since there is a relatively large distance from where the servo is mounted to where the carbon brace plate (with the ballrace in it) is mounted the vibration on both points may not be in phase or of equal amplitude.

What most likely will save the servo is the mechanical decoupling between the servo shaft and the potmeter.

The Fury also has this type of brace and there the servo and the brace where optionally even mounted on carbon. I have not heard of excessive servo failure because of vibration due to this construction so it may not be an issue.
03-15-2006 Over year old.
 
 
Helinutnz
Elite Veteran
Location: below 42 South

Yes quite right. I am wrong there.
It's a well proven design feature so should stand the test of time in the Synergy.
I hate to think just how much our servo's go through in terms of vibration even in the best heli.
03-15-2006 Over year old.
 
 
blade3d
Elite Veteran
Location: New Jersey

Did you noctice the engine mount on the Synergy is plastic , how much vibration you think that will reduce ??



Blade3d
03-15-2006 Over year old.
 
 
Colibri
Key Veteran
Location: The Netherlands

Quote 
Did you noctice the engine mount on the Synergy is plastic , how much vibration you think that will reduce ??

Some but definitely not all because otherwise we would have vibration free Raptors
03-15-2006 Over year old.
 
 
Helinutnz
Elite Veteran
Location: below 42 South

Maybe a good quality composite mount might reduce vibes and anything is better than nothing. Also a lot of guys like plastic for blade holders due to flying qualities and plastic appears to be easier on bearings than metal. Perhaps they did some research on it and found the composite was better in this regard?
03-15-2006 Over year old.
 
 
heliman
Senior Heliman
Location: Fullerton, CA

Bull#&%$

Most of the plastic vs. metal stuff people are talking about is BULL.

To feel the difference between the plastic and metal bellcranks on a Fury or the Synergy would be impossible. The same goes for the bearing blocks. These blocks are compressed between metal, G-10, or carbon frames, usually with metal inserts, a la Raptor 90.

People buy most metal parts because they LIKE the looks or because it's more reliable; however, bellcranks, motor mounts, and bearing blocks don't fall into the reliability category.
03-15-2006 Over year old.
 
 
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Synergy R/C Synergy N9 > Synergy bellcrank geometry?
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