All VP's move toward the low pitch stop in steps rather than in a smooth
motion. And all VP's will change to a lower pitch when the prop hits
something. This happens because there is friction in the mechanism. IMHO
it is impossible to eliminate the friction. Of course if you can reduce
the friction then the steps will be smaller and more frequent and
changes from bumps will be smaller.
Another thing to look out for is whether friction is keeping the prop
from going to the high pitch stop before launching. I always make sure
that the mechanism is against the high pitch stop by twisting the prop
hook a little.
Probably most everyone knows this by now but when you are checking your
hub for movement vs. torque you must do this when the torque is
decreasing. Checking it when the torque is increasing doesn't prove
anything because of the friction mentioned above.
On 3/6/2013 11:06 AM, Yuan Kang Lee wrote:
>
>
> I look forward to your feedback -- how it can be constructed simpler,
> alternate materials, etc.
>
> The hub is strong and light, at 70 mg. It should withstand the impact
> of an exploding motor.
>
> There is one kink to be worked out. Although the hub's action is very
> smooth when you work it in your hand, in flight, I believe there is
> some binding. In a normal flight, this means that the return to low
> pitch happens in jumps. I heard it pop into low pitch this past
> weekend in the F1D contests. The flight result was still very good --
> I flew a 14:45 with a half motor at 25'.
>
> The big problem happens when the prop hits the ceiling, obstructions,
> or when the model is steered from the front. The VP goes into low
> pitch and is stuck there -- this happened when I flew in Atlanta. At
> Torrance, I flew no touch, so this problem was not detrimental to the
> final result.
>
> When I started building VP's back in October last year, I built one or
> two of every existing type to better understand how they work. Two
> things struck me -- the existing VP hubs require precise fit of
> components, and the wire hinge was the smoothest. These observations
> led to this VP hub, which uses a modified wire hinge and does not
> require a precise fit. (I'll go into this later.)
>
> I was mostly excited when I thought that this VP hub may be accessible
> to everyone. I guess we'll have to see about that.
>
> I want to extend this design to F1M / Pennyplane and any larger and
> heavier indoor models. I hope this would encourage more people to fly
> VP's indoor. I have espoused before that indoor flying in a low
> ceiling gym using a VP is the "ultimate". It allows gentle flying of
> our models, and brings maximum enjoyment if indoor flying.
>
> -Kang
>
> --- In Indoor_Construction_at_yahoogroups.com
> <mailto:Indoor_Construction%40yahoogroups.com>, Nick Ray wrote:
> >
> > Hello Everyone,
> >
> > The INAV site has been updated with an article on Kang's hub. I want to
> > thank Kang for putting that together for us so quickly.
> >
> > http://indoornewsandviews.wordpress.com/
> >
> > Regards,
> >
> > Nick
> >
>
>
Received on Wed Mar 06 2013 - 08:29:59 CET