>      > Care to make a 3D dwg for me? I can't see how it would > work with
>     counter
>      > rotating
>      > rotors?
>      >
>      > Paul Lamar
> >     Paul,
>     How are you going to get in and out of this VTOL?
>     George ( down under)
> > >     A step ladder.
> >     --
>     Paul Lamar ...No rotor no motor.
> > > Small low-drag hand holds and foot depressions built into the > fuselage.
> I'm trying to locate a small planetary to build a 1/5 RC scale > model -
> any ideas?
> > Perry
> > Piston or electric? https://sdp-si.com/eStore/ Key words internal > gears.http://bostongear.com/products/enclosed/gearhead.html
> > "Due to the load sharing attributes of multiple tooth contacts, > planetarygearboxes provide the highest torque and stiffness for > any given envelope.
> Balanced planetary kinematics at high speeds combined with the > associatedload sharing make planetary-type gearheads ideal for > servo applications."
> > "True helical technology provides increased tooth to tooth contact > ratio by
> 33% vs. spur gearing
> 12° helix angle produces smooth and quiet operation
> One piece planet carrier and output shaft design reduces backlash
> Single step machining process
> Assures 100% concentricity
> Increases tortional rigidity"
> > > Sounds like Ford C6 planetary gears :)
> > > Paul Lamar ...No rotor no motor.

Paul, those look like Thompson's. I've got 4 of them on my milling machine.They have very little backlash [3 or 4 arc-seconds if I remember right]
The down side of them is that they would weigh as much as the rest
of the model just in themselves. They are surprisingly heavy little buggers.
Also, they aren't cheap..  ~$600-1500 a pc depending on what you buy..
They also have a reduced rpm limit [usually] and this isn't a problem for
their typical use as your average DC servo only run's up to 3 or 6k rpm.

If your not terribly picky about the exact ratio, there are a handful for sale on
ebay [or were a couple weeks ago] they are the 'Rhino' brand and he had
them on for 19.99 starting bid, but no-one ever bid on them because they
are metric [ I think]  if a person was 'as building ' to fit it wouldn't really
matter. I believe they were 10:1 reducers.

A Nema17 frame unit might be your best bet. Your not going to be puttingbuckets of Hp through them, and they'd be the smallest/lightest'variety. The down side is I've never seen them sell on Ebay so you
might need to go for a new one.. $$.

Jarrett

I was thinking the PL5050. I don't know how that relates to the Nema 17 frame.
The weight is .6 kg or 1.3 pound which I think can be cut down on a lathe.
The housing looks real thick.
Max input RPM is 10K but I think 20K will be OK for  a short time.
Also the front bearing can be replaced by a needle bearing which will also cut the weight.
The back housing can be changed to thinner aluminum. The main thing we are looking
for is the gears and the planet carrier. A fifth scale model will have a wing span
of 2 feet. If Perry sends me one I will cut it down.
-- 
Paul Lamar ...No rotor no motor.

Sounds good.. let me know if I can help w/ the model I used to
be an avid R/c'er.. [well till I got married a couple years ago,
since then.. BMW=gone.. R/c planes=gone.. R/c Heli.. well it's still
in the basement.. but needs parts.. sigh..]

It'd be fun to bang out some quick molds to make the parts for it..
It'd be just as easy to make it a bit bigger as well.. get a bit more
realistic dynamic's.. say 1/4 scale..??

Those reducers wouldn't care they'd still be more than is needed..

Jarrett

A quarter scale delta would be great. 2.5 foot wingspan.

We could even get a model rotary engine and put in it. I'll help Perry.