Another method to align and attach tubes:
Insert a tight fitting metal tube thru both tissue (polyimide, carbon,
fiberglass) tubes.
Tack glue a piece of balsa (say 1/16" square) to the outside of both
tubes as a "bridge" between them.
Remove the metal tube.
Tack glue the balsa/tissue tube assembly to the carbon rods.
Remove the balsa bridge.
Finish the attachment in whatever way you prefer.
(borrowed and modified from the kevlar hinge hub build instructions)
On 3/7/2013 11:29 AM, Jake Palmer wrote:
> I'll do a full post on my VP mechanism as I build it. I started with
> the yoke because I already had the carbon for it.
>
> Also I was thinking about how to add a tube to your mechanism
> yesterday and I have a pretty simple way to do it. I'm going to drill
> a .020 hole in the end of a piece of a short piece 1/8" square balsa.
> Then I'll insert and glue the .020 carbon rod into that hole. After
> that I'll chuck the carbon rod into a pin vise and chuck the pin vise
> into my drill press. I'm going to use it like a lathe to sand down
> the balsa to the diameter I want. I'm planning to buy some .064 ID
> polyimide tubing so I'll aim for that diameter. I think this will work.
>
>
> On Thu, Mar 7, 2013 at 8:06 AM, Yuan Kang Lee <ykleetx_at_gmail.com
> <mailto:ykleetx_at_gmail.com>> wrote:
>
> Mike and Jake,
>
> It would be great if you guys share with us your build progress of
> the carbon VP on Hip Pocket. I don't plan to build another VP
> until after Kent.
>
> -Kang
>
>
>
> --- In Indoor_Construction_at_yahoogroups.com
> <mailto:Indoor_Construction%40yahoogroups.com>, "Yuan Kang Lee"
> <ykleetx_at_...> wrote:
> >
> >
> > You can attach a tube to the "spar rod" to allow you an easier
> retrofit of the prop blade. I didn't for two reason -- first the
> weight reason. Second, aligning the tubes would require a lot of
> work, in addition to the work of aligning the completed prop after
> the prop blades are inserted.
> >
> > But what I have done on the first prototype makes attaching prop
> blades a challenge, to say the least. Attaching the spar to the
> the spar rod before the prop outline/ribs are built will be easier.
> >
> > --- In Indoor_Construction_at_yahoogroups.com
> <mailto:Indoor_Construction%40yahoogroups.com>, "Yuan Kang Lee"
> <ykleetx_at_> wrote:
> > >
> > > Brown, Kagan, Richmond, Cailliau, Schramm, ... don't use tubes.
> > >
> > > Who's old fashioned, modern, and post-modern?
> > >
> > > I agree that retrofitting a prop with different blades is a
> good feature. However, I don't think doing so at the flying site
> (during a contest) is the right thing. Retro-fitting should be a
> planned activity, IMO. I don't carry around back-up prop blades.
> If I had back-up prop blades, I would build another VP hub and
> complete the unit and test the unit as a whole.
> > >
> > > When I attach the blades, I make sure that the whole prop is
> aligned. The prop alignment is adjustable because I use Ambroid
> (with kevlar and tissue) to attach the prop spar to the carbon
> "spar rod".
> > >
> > >
> > > --- In Indoor_Construction_at_yahoogroups.com
> <mailto:Indoor_Construction%40yahoogroups.com>, "mkirda_at_"
> <mkirda_at_> wrote:
> > > >
> > > > Call me old-fashioned, but I want a tissue tube in there
> somewhere...
> > > >
> > > > Seems too easy for a blade to get slightly misaligned with
> no way to adjust. Also if a blade breaks, I want to have spares
> available that I could easily add. (After breaking two prop blades
> last night, I see a lot of advantages to this.)
> > > >
> > > > Regards.
> > > > Mike Kirda
> > > >
> > > > --- In Indoor_Construction_at_yahoogroups.com
> <mailto:Indoor_Construction%40yahoogroups.com>, "Yuan Kang Lee"
> <ykleetx_at_> wrote:
> > > > >
> > > > > Gary,
> > > > >
> > > > > > What keeps the .020 carbon rod from sliding out
> > > > > > of the .020/.040 tube? Is it the .011 rod in the .015 hole?
> > > > >
> > > > > Yes.
> > > > >
> > > > > > the prop spar is glued into the .020 carbon rod.
> > > > >
> > > > > Yes, the prop spar needs to be attached to the .020 carbon
> rod and the .011 rod. There are several ways to do this, and I
> will take some time to explain in better detail in the next couple
> of days. For now, here is the quick description, including how the
> sparless blade is constructed.
> > > > >
> > > > > A Blade Construction
> > > > >
> > > > > - form outline (wet) with twist on prop block 1
> > > > > - on another prop block 2, put down double sided tape
> along a trace of the outline
> > > > > - place dried outline with twist on block 2, using double
> sided tape to hold the outline down
> > > > > - put in temporary straight ribs
> > > > > - apply boron to first side
> > > > > - remove outline carefully from prop block, place outline
> with boron side down on block
> > > > > - apply boron to second side
> > > > > - replace temporary straight ribs with real ribs
> > > > >
> > > > > B cover
> > > > >
> > > > > C glue on spar
> > > > >
> > > > > D put on VP hub
> > > > >
> > > > > I'm experimenting with orders of steps B,C,D. One way is
> C,B,D.
> > > > >
> > > > > Another way is (a la Steve Brown):
> > > > >
> > > > > - glue prop spar to 020 rod and 011 lever arm before
> assembling VP hub
> > > > > - assemble VP hub
> > > > > - build outline/ribs on VP hub + spar assembly
> > > > > - cover
> > > > >
> > > > >
> > > > >
> > > > > --- In Indoor_Construction_at_yahoogroups.com
> <mailto:Indoor_Construction%40yahoogroups.com>, Warthodson_at_ wrote:
> > > > > >
> > > > > >
> > > > > > Kang,
> > > > > > Thanks for posting the VP hub photos & text. The
> diagrams & dimensions were especially helpful. As I understand it,
> the prop spar is glued into the .020 carbon rod. What keeps the
> .020 carbon rod from sliding out of the .020/.040 tube? Is it the
> .011 rod in the .015 hole?
> > > > > > Gary Hodson
> > > > > >
> > > > > >
> > > > > > -----Original Message-----
> > > > > > From: Yuan Kang Lee <ykleetx_at_>
> > > > > > To: Indoor_Construction
> <Indoor_Construction_at_yahoogroups.com
> <mailto:Indoor_Construction%40yahoogroups.com>>
> > > > > > Sent: Wed, Mar 6, 2013 10:06 am
> > > > > > Subject: [Indoor_Construction] Re: carbon VP hub data?
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > 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 Thu Mar 07 2013 - 08:54:44 CET