REFLECTOR: Nosewheel shimmy_1

[Laurence Coen]

I'm the Nylon washer guy.  It replaces the fiber washer, not the Bellville 
washers.  Initially it works great.  Easy to steer on the ground and no 
shimmy so far.  It will take time and a lot more landings to find out if 
this is a great idea or another flop.

Larry Coen
N136LC
SE/RG Franklin/IVO

----- Original Message ----- 
From: "Andy Millin" <amillin at sbcglobal.net>
To: "'Velocity Aircraft Owners and Builders list'" <reflector at tvbf.org>
Sent: Tuesday, June 27, 2006 8:20 AM
Subject: REFLECTOR: Nosewheel shimmy_1


> Sid,
>
> Could you resend your picture?  For some reason I didn't receive the 
> email.
>
> Thanks for doing the research.
>
> One of the builders had made a Nylon washer to replace the belville
> arrangement.  I would like to see a picture of the Nylon solution.
>
> Sid, I like your style.  Asking this group to come up with possible modes 
> of
> failure is like asking who wants free pie and chips.  :)
>
> I haven't seen the picture yet...
>
> -- You have a hard landing, maybe a few over time and it separates and 
> goes
> through the prop
>
> From Rich Guerra's videos you can watch the nose gear touch down.
> When it comes down "plop" it appears it would shake the dampener rather
> violently.
>
> -- It bends the fork over time
>
> -- It gets caught in the door upon retraction or extension
>
> -- It costs more, weights more and adds complexity
>
> -- Possible balance issue combined with a looser nut lets it flip around 
> 180
> -- gear is backwards when you try to retract or extend ... Possibly on 
> touch
> down
>
> -- Attach point creates a stress riser in the main gear fork.  Over time 
> the
> fork cracks
>
> Truth can be stranger than fiction.
>
> We will never know what the problems are if it isn't tried and the real
> information gathered.  Thanks again for giving it your time and letting us
> know what you find.
>
> On a related note:
>
> I had spoken with my brother, also a pilot as well as president of a
> machining company.  Alex had mentioned a type of hydraulic dampener that
> could be a solution.  My brother agreed this could be a solution and 
> pointed
> me to a few websites to see "like" examples.
>
> He immediately had concerns about the cost, size, weight and durability 
> over
> time.  His opinion was we could try it, but it would be expensive and had 
> a
> high probability of being a less than perfect solution.  Not to mention 
> you
> will be testing it on your $200K aircraft.
>
> This has been a longstanding issue for aircraft with castering nose 
> wheels.
> Trying to find an elegant solution must not be easy.
>
>
>
>
>
>
>
>
>
>
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