REFLECTOR: Roll trim mod suggestions

[Don Johnston]

That would require a definition of "broke" and "fix".  ;-)

For example:

The belleville washers on the nose gear have been in use for many years.
That would indicate it ain't broke. Yet Velocity has been working on a
shimmy damper.

An additional hydraulic cylinder to close the nose gear doors has been in
the manual since the retract has been offered. Yet many people have gone
with a mechanical mechanism.

Airplanes has been flying on steam gauges for about 100 years. So that
clearly ain't broke. But Just about every new plane being built today has a
glass panel.

And don't get me started on engines. :-)

As for me and the roll trim, one of the things I kept seeing were comments
about the roll trim slipping and how belt dressing, extra turns of the
cord, fairy dust and other approaches would "fix" it. That to me, indicated
a potential for improvement. Unfortunately, I belatedly realized that since
the motor has continuous rotation there there has to be some slippage. So
now I have the timing belt parts installed and this looks like a solution
that will provide positive motion and allow the belt to slip should the
travel exceed the allowable limits.

The point is that most of us have undertaken our projects because we are
comfortable with making (what we think are) improvements to the "book"
design. Some, more than others.

Stepping down off the soapbox now.
Don

On Sun, Dec 15, 2013 at 6:03 AM, Carl Hoffman <hoffman3 at rcn.com> wrote:

> What ever happen to; "If it ain't broke why fix it?"
>
>
> Sent from my iPad.
>
>
> On Dec 14, 2013, at 11:14 PM, Rene Dugas <renedugas at gmail.com> wrote:
>
> Jorge monitors the reflector.
> Comment:  Roll trombone from the factory works.  Mine slipped a little
> when new but one additional wrap of the cord and some polishing compound on
> the cord for grip fixed it.  There are so many other places one can tweek
> the plane with less risk. Modifying controls is a slippery slope.
> 680 hrs flying 10.5 yrs. trim with No maintenance.  KISS.
> YMMV.
>
> Sent from Rene's iPad. A pleasure.  Go Apple.
>
>
> On Dec 12, 2013, at 10:49 AM, Brian Michalk <michalk at awpi.com> wrote:
>
> Also, someone asked about an aerodynamic trim.
>
> Jorge Bujanda was working on such a beast, if I recall.  Does anyone know
> how that worked out?
>
> On 12/12/2013 10:06 AM, Ron N VelocityXLFG wrote:
>
> Got my belt and pulleys here
>
> http://www.mcmaster.com/#timing-belt-pulleys/=prz4ya
>
>
>
> On 12/11/2013 5:27 PM, Don Johnston wrote:
>
>   Thanks for the replies!
>
>  I thought about a limiting cable that would prevent the motor from
> rotating.  But making sure it was strong enough and making sure it didn't
> cause a problem in "slack" mode was problematic.
>
>  The clutch is an interesting approach. But the cost and space made that a
> non-starter.
>
>  So I've removed the parts and ordered the smallest timing pulley I could
> find with a .25" bore.  I'll open it to 5/16" and try that. The nice thing
> about the timing belt is that you can control how much slippage is allowed
> with spring tension.
>
>  Thanks again,
> Don
>
>
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