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Damper?

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tbonsell(at)luxuria.com
Guest

Posted: Wed May 14, 2008 5:40 am Post subject: Damper?

Hi guys, I have a stupid question.



Back in the day, I used to ride motorcycles. Anyway, on a  

particularily nasty kawi triple, it had a steering damper to minimize  

the terrifying speed wobble that would try and kill you from time to  

time. It looked like a tiny shock absorber.



How come they don't use these to damp out flutter in control surfaces?

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Wed May 14, 2008 5:55 am Post subject: Re: Damper?

I actually thought about this too. Good point. I know I've seen them on the nose wheels of Cessnas. I've had a nosewheel shimmy and shake while going down the runway (like a shopping cart wheel) and it REALLY shook the plane hard too. I turned around and took it back to the shop. The owner/rentee fixed it on the spot, was a bad damper or connection or something.



 	  tbonsell(at)luxuria.com wrote: 	
		  Hi guys, I have a stupid question.



Back in the day, I used to ride motorcycles. Anyway, on a  

particularily nasty kawi triple, it had a steering damper to minimize  

the terrifying speed wobble that would try and kill you from time to  

time. It looked like a tiny shock absorber.



How come they don't use these to damp out flutter in control surfaces?

Al Hays

Joined: 01 Oct 2007
Posts: 42
Location: Gore, VA

Posted: Wed May 14, 2008 6:40 am Post subject: Damper?

Tony,



  I  remember being invited to test ride one of those in while  

stationed in Japan when they were new on the market.  My first and  

only unintentional wheelie from the wicked power curve.



That must not be such a stupid question since I thought of the same  

thing myself.  I didn't give it much consideration after remembering  

a few occasions of frozen (seized up) shock absorbers

on land vehicles.  Those devices are used as well for sway dampening  

for trailer hitches and shimmy control.  The consequences of having  

one stick or freeze up in flight would be more dire than on a ground  

vehicle.  However, I have not researched and don't know if they have  

in fact been used on control services.



Al Hays

N5892H reserved



On May 14, 2008, at 9:37 AM, Tony Bonsell wrote:



 	  Quote: 	
		   



 Hi guys, I have a stupid question.



 Back in the day, I used to ride motorcycles. Anyway, on a  

 particularily nasty kawi triple, it had a steering damper to  

 minimize the terrifying speed wobble that would try and kill you  

 from time to time. It looked like a tiny shock absorber.



 How come they don't use these to damp out flutter in control surfaces?

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Wed May 14, 2008 7:01 am Post subject: Re: Damper?

How about a damper made of two pieces of nylon that clamp down on an aluminum plate with springs under the bolt heads? That would be light and would never freeze up or lose oil. It would just provide some consistant stiffness to the actuator in both directions.



I could see an arrangment like this working well with the push-tube style aileron control. Use the existing horn that's mounted on #7 rib inside the wing, and with the unused side of the horn (being that there's no cable there) attach the damper to gently clamp down on the unused portion of horn. Very little adjustments to be made for the installation, there's already an access hole for getting to the linkage.



Plus that rib is already beefed up to handle the cable actuator and horn.



You'd probably need to make a different style horn that has a longer arm on it to go back into the damper.

 	  Al Hays wrote: 	
		  Tony,



  I  remember being invited to test ride one of those in while  

stationed in Japan when they were new on the market.  My first and  

only unintentional wheelie from the wicked power curve.



That must not be such a stupid question since I thought of the same  

thing myself.  I didn't give it much consideration after remembering  

a few occasions of frozen (seized up) shock absorbers

on land vehicles.  Those devices are used as well for sway dampening  

for trailer hitches and shimmy control.  The consequences of having  

one stick or freeze up in flight would be more dire than on a ground  

vehicle.  However, I have not researched and don't know if they have  

in fact been used on control services.



Al Hays

N5892H reserved



On May 14, 2008, at 9:37 AM, Tony Bonsell wrote:



 	  Quote: 	
		   



 Hi guys, I have a stupid question.



 Back in the day, I used to ride motorcycles. Anyway, on a  

 particularily nasty kawi triple, it had a steering damper to  

 minimize the terrifying speed wobble that would try and kill you  

 from time to time. It looked like a tiny shock absorber.



 How come they don't use these to damp out flutter in control surfaces?

Gig Giacona

Joined: 10 Jan 2006
Posts: 1416
Location: El Dorado Arkansas USA

Posted: Wed May 14, 2008 7:49 am Post subject: Re: Damper?

I am curious. How is that any better than a cable running all the way to the horn in the other wing that applies and releases pressure as needed?

 	  ashontz wrote: 	
		  How about a damper made of two pieces of nylon that clamp down on an aluminum plate with springs under the bolt heads? That would be light and would never freeze up or lose oil. It would just provide some consistant stiffness to the actuator in both directions.

_________________
W.R. "Gig" Giacona
601XL Under Construction
See my progress at www.peoamerica.net/N601WR

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Wed May 14, 2008 7:56 am Post subject: Re: Damper?

I'm talking about a damper on each aileron horn, particularly in the push-tube setup.



In the cable setup, the cable running to the other aileron doesn't provide any damping, it's just a hookup to the other side. There may be some friction there, but not like a damper would provide. What I'm talking about is a friction plate as a damper which would help resist out of control high frequency movement of the ailerons (flutter). The skin aileron hinge may be inadvertantly acting as a damper in that it's a stiffer joint to move.



 	  Gig Giacona wrote: 	
		  I am curious. How is that any better than a cable running all the way to the horn in the other wing that applies and releases pressure as needed?

 	  ashontz wrote: 	
		  How about a damper made of two pieces of nylon that clamp down on an aluminum plate with springs under the bolt heads? That would be light and would never freeze up or lose oil. It would just provide some consistant stiffness to the actuator in both directions.

Al Hays

Joined: 01 Oct 2007
Posts: 42
Location: Gore, VA

Posted: Wed May 14, 2008 8:32 am Post subject: Damper?

Do not archive.

Several aspects of that to consider.

1. It would make more resistance and therefore more force to be  

carried by the cables and probably more frequent adjustment due to wear.

2. As I recall, shock absorbers usually give more resistance to  

movement in one direction than the other.  Push down with all your  

weight on the front end of the Buick with worn out shocks and it will  

bob up and down for awhile.  Replace the shocks and you still push it  

down easily but it will not bounce.  The harder you try to push that  

air and fluid through the orifice inside the shock the more  

resistance it seem to have.  Conversely, the harder you push  

something on a nylon bearing surface, the less effect it will have on  

controlling that movement.

3. The resistance, or dampening, provided by spring loading friction  

would make the control feel heavier but probably be overcome easily  

by a flutter condition.

4. Sounds like a handy way to keep linkage snug on a lawn tractor but  

not up to the demands of flight controls.

Please don't take offense.  Better to bounce these ideas around  

before implementing them and being the test pilot.

On May 14, 2008, at 11:01 AM, ashontz wrote:

 	  Quote: 	

 How about a damper made of two pieces of nylon that clamp down on  

 an aluminum plate with springs under the bolt heads? That would be  

 light and would never freeze up or lose oil.

 Al Hays wrote:

> Tony,

>

>   I  remember being invited to test ride one of those in while

> stationed in Japan when they were new on the market.  My first and

> only unintentional wheelie from the wicked power curve.

>

> That must not be such a stupid question since I thought of the same

> thing myself.  I didn't give it much consideration after remembering

> a few occasions of frozen (seized up) shock absorbers

> on land vehicles.  Those devices are used as well for sway dampening

> for trailer hitches and shimmy control.  The consequences of having

> one stick or freeze up in flight would be more dire than on a ground

> vehicle.  However, I have not researched and don't know if they have

> in fact been used on control services.

>

> Al Hays

> N5892H reserved

>

> On May 14, 2008, at 9:37 AM, Tony Bonsell wrote:

>>

>>

>>  Hi guys, I have a stupid question.

>>

>>  Back in the day, I used to ride motorcycles. Anyway, on a

>>  particularily nasty kawi triple, it had a steering damper to

>>  minimize the terrifying speed wobble that would try and kill you

>>  from time to time. It looked like a tiny shock absorber.

>>

>>  How come they don't use these to damp out flutter in control  

>> surfaces?

>>

>>

>>

>

 --------

 Andy Shontz

 do not archive

 CH601XL - Corvair

 www.mykitlog.com/ashontz

 Read this topic online here:

 http://forums.matronics.com/viewtopic.php?p=183123#183123

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Wed May 14, 2008 8:37 am Post subject: Re: Damper?

Has no one noticed I said, push-tube?

 	  Al Hays wrote: 	
		  Do not archive.

Several aspects of that to consider.

1. It would make more resistance and therefore more force to be  

carried by the cables and probably more frequent adjustment due to wear.

2. As I recall, shock absorbers usually give more resistance to  

movement in one direction than the other.  Push down with all your  

weight on the front end of the Buick with worn out shocks and it will  

bob up and down for awhile.  Replace the shocks and you still push it  

down easily but it will not bounce.  The harder you try to push that  

air and fluid through the orifice inside the shock the more  

resistance it seem to have.  Conversely, the harder you push  

something on a nylon bearing surface, the less effect it will have on  

controlling that movement.

3. The resistance, or dampening, provided by spring loading friction  

would make the control feel heavier but probably be overcome easily  

by a flutter condition.

4. Sounds like a handy way to keep linkage snug on a lawn tractor but  

not up to the demands of flight controls.

Please don't take offense.  Better to bounce these ideas around  

before implementing them and being the test pilot.

On May 14, 2008, at 11:01 AM, ashontz wrote:

 	  Quote: 	

 How about a damper made of two pieces of nylon that clamp down on  

 an aluminum plate with springs under the bolt heads? That would be  

 light and would never freeze up or lose oil.

 Al Hays wrote:

> Tony,

>

>   I  remember being invited to test ride one of those in while

> stationed in Japan when they were new on the market.  My first and

> only unintentional wheelie from the wicked power curve.

>

> That must not be such a stupid question since I thought of the same

> thing myself.  I didn't give it much consideration after remembering

> a few occasions of frozen (seized up) shock absorbers

> on land vehicles.  Those devices are used as well for sway dampening

> for trailer hitches and shimmy control.  The consequences of having

> one stick or freeze up in flight would be more dire than on a ground

> vehicle.  However, I have not researched and don't know if they have

> in fact been used on control services.

>

> Al Hays

> N5892H reserved

>

> On May 14, 2008, at 9:37 AM, Tony Bonsell wrote:

>>

>>

>>  Hi guys, I have a stupid question.

>>

>>  Back in the day, I used to ride motorcycles. Anyway, on a

>>  particularily nasty kawi triple, it had a steering damper to

>>  minimize the terrifying speed wobble that would try and kill you

>>  from time to time. It looked like a tiny shock absorber.

>>

>>  How come they don't use these to damp out flutter in control  

>> surfaces?

>>

>>

>>

>

 --------

 Andy Shontz

 do not archive

 CH601XL - Corvair

 www.mykitlog.com/ashontz

 Read this topic online here:

 http://forums.matronics.com/viewtopic.php?p=183123#183123

Gig Giacona

Joined: 10 Jan 2006
Posts: 1416
Location: El Dorado Arkansas USA

Posted: Wed May 14, 2008 10:34 am Post subject: Re: Damper?

Yes and you probably need it even less with a push tube than cables.

 	  ashontz wrote: 	
		  Has no one noticed I said, push-tube?

_________________
W.R. "Gig" Giacona
601XL Under Construction
See my progress at www.peoamerica.net/N601WR

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Wed May 14, 2008 10:36 am Post subject: Re: Damper?

Maybe so, I was just responding to ways a damper could be implemented.



 	  Gig Giacona wrote: 	
		  Yes and you probably need it even less with a push tube than cables.

 	  ashontz wrote: 	
		  Has no one noticed I said, push-tube?

Ron Lendon

Joined: 10 Jan 2006
Posts: 685
Location: Clinton Twp., MI

Posted: Wed May 14, 2008 4:54 pm Post subject: Re: Damper?

Andy,



Are you using an alias?  Are you a US Certificated Pilot?  Do you have and engineering degree or are you a student like the rest of us?



The reason I ask these questions is I like to know who I'm listening to.  You have been a very active participant in many of the discussions and you appear to be redesigning your airplane.  If I am to consider your proposals I would really like to know more about you.



What say you?



do not archive

_________________
Ron Lendon
WW Corvair with Roy's Garage 5th bearing
CH 601 XLB
N601LT - Flying
http://www.mykitlog.com/rlendon
Corvair Engine Prints:
https://sites.google.com/site/corvairenginedata/

notsew_evets(at)frontiern
Guest

Posted: Wed May 14, 2008 5:08 pm Post subject: Damper?

Listed in the FAA registry ?



Take a look.    Amazing results...



---

larry(at)macsmachine.com
Guest

Posted: Wed May 14, 2008 5:29 pm Post subject: Damper?

Ron,

I'd recommend you stay the course and not change anything shown by the 

drawings.  The changes that have been proposed are all contentious without

approval from Zenith.  The vast majority of the 601s flying today will 

be flying years from now if they were built to the drawings.  Trust the 

designer, not

the instinct to arbitrarily strengthen or complicate things suggested by 

others.   You don't have a reason to become a test pilot for anyone!



Larry McFarland

601HDS at www.macsmachine.com



Ron Lendon wrote:

 	  Quote: 	
		   



 Andy,



 Are you using an alias?  Are you a US Certificated Pilot?  Do you have and engineering degree or are you a student like the rest of us?



 The reason I ask these questions is I like to know who I'm listening to.  You have been a very active participant in many of the discussions and you appear to be redesigning your airplane.  If I am to consider your proposals I would really like to know more about you.



 What say you?



 do not archive



 --------

 Ron Lendon, Clinton Township, MI

 Corvair Zodiac XL, ScrapBuilder 

 http://www.mykitlog.com/rlendon

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