Making the carbon yoke is easy enough, Kang.
I was planning to make some new hubs as they are now the weakest part of my F1D program IMO. It would be easy enough to make a half-round rather than V groove when making the form.
One issue I have had in the past with using the .005" carbon uni cloth is after drilling, the part between the screws tended to delaminate. I thought that two layers of the .003 carbon but at maybe 20 degree angles would eliminate this. A touch heavier perhaps.
Alternatively, a small strip of 0.6 oz fiberglass could be overlayed during the layup. Given that I have 0.005" carbon and 0.6 oz fiberglass, I will probably try that first with the Rohacell I have (and haven't tried yet.)
Might be next week before I can get to it.
Regards.
Mike Kirda
--- In Indoor_Construction_at_yahoogroups.com, "Yuan Kang Lee" <ykleetx@...> wrote:
>
> Mike,
>
> The two screw holders are separate only for convenience of the first prototype. Each has to be glued to the "hub" of the VP, then tied with Kevlar. Next version will have the screw holders all on the left side of the hub.
>
> I'm interested if you could vacuum form one a la Treger. Can you think how to make one? We could also think about kitting this design. Interested?
>
> I have not tried a lubricant other than my rubber lube :)
>
> The "hub" is an off-the-shelf carbon tube.
>
> --- In Indoor_Construction_at_yahoogroups.com, "mkirda@" <mkirda@> wrote:
> >
> > Just a few questions, Kang.
> >
> > Why the two arms for screws rather than the yoke arrangement ala Treger?
> >
> > Regarding the 'binding', did you use lubricant already?
> > Silicon? Oil? Graphite?
> >
> > I assume your carbon bar has holes at the end rather than slots? And the holes are used to retain the blades in the hub? How do you attach the blades?
> >
> > Neat design in many ways, especially if binding isn't that much of an issue.
> >
> > Regards.
> > Mike Kirda
> >
> >
> >
> > --- In Indoor_Construction_at_yahoogroups.com, "Yuan Kang Lee" <ykleetx@> 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, Nick Ray <lasray@> 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 - 08:58:44 CET