R/C Flying, pt 3 - Junkers 52.jpg (1/1)

[Mitchell Holman]

[Alan Erskine[_3_]]

"Mitchell Holman" > wrote in message
...

Superb! Only thing; I thought the Ju52 had three-bladed props. Other than
that, it's an excellent model.

[Mitchell Holman]

"Alan Erskine" > wrote in
:

> "Mitchell Holman" > wrote in message
> ...
>
> Superb! Only thing; I thought the Ju52 had three-bladed props. Other
> than that, it's an excellent model.
>

The models of the Corsair and the Avenger also have
two-bladed props instead of three. Must be an R/C thing.

[Waldo.Pepper[_2_]]

Often it all depends on the engine. More powerful engine, more blades.

Here is a Tante Ju with two blade props.

http://cdn-www.airliners.net/aviation-photos/middle/4/0/7/1365704.jpg

Waldo.


On Fri, 04 Jul 2008 13:53:51 GMT, "Alan Erskine"
> wrote:

>Superb! Only thing; I thought the Ju52 had three-bladed props. Other than
>that, it's an excellent model.
>

[Alan Erskine[_3_]]

"Mitchell Holman" > wrote in message
...
> "Alan Erskine" > wrote in
> :
>
>> "Mitchell Holman" > wrote in message
>> ...
>>
>> Superb! Only thing; I thought the Ju52 had three-bladed props. Other
>> than that, it's an excellent model.
>>
>
> The models of the Corsair and the Avenger also have
> two-bladed props instead of three. Must be an R/C thing.

I thought it might be an 'engine thing'. Thanks Mitchell and Waldo.

[Guybrush Threepwood[_2_]]

"Waldo.Pepper" > schrieb im Newsbeitrag
...
> Often it all depends on the engine. More powerful engine, more blades.
>
> Here is a Tante Ju with two blade props.
>
> http://cdn-www.airliners.net/aviation-photos/middle/4/0/7/1365704.jpg
>
> Waldo.
>
>
> On Fri, 04 Jul 2008 13:53:51 GMT, "Alan Erskine"
> > wrote:
>
>>Superb! Only thing; I thought the Ju52 had three-bladed props. Other
>>than
>>that, it's an excellent model.
>>
>


Most of the JU52/3M were built with either BMW or Pratt & Whittney engines.
The BMW version has originally two blade props and the P&W version has 3
blade props.
The P&W engines are providing more power, therefore, as mentioned above the
need for 3 blade probs.
But the sound is not the same....:-)

--
Gruß Guybrush

[Richard[_7_]]

Did the Germans just buy the P&W's or did they manufacture them in Germany?

>
> Most of the JU52/3M were built with either BMW or Pratt & Whittney
> engines. The BMW version has originally two blade props and the P&W
> version has 3 blade props.
> The P&W engines are providing more power, therefore, as mentioned above
> the need for 3 blade probs.
> But the sound is not the same....:-)
>
> --
> Gruß Guybrush

[D. St-Sanvain]

Hello;

Alan Erskine a écrit :
> Superb! Only thing; I thought the Ju52 had three-bladed props. Other than
> that, it's an excellent model.

Here's view of two different propellers sets :
http://www.warbirdz.net/largepic.php?ID=2365

Bye

[Herman]

"D. St-Sanvain" > schreef in bericht
...
> Hello;
>
> Alan Erskine a écrit :
>> Superb! Only thing; I thought the Ju52 had three-bladed props. Other
>> than that, it's an excellent model.
>
> Here's view of two different propellers sets :
> http://www.warbirdz.net/largepic.php?ID=2365
>
> Bye
>
>
I thought most wartime Ju-52/3m's had 2-bladed props.
Possibly CASA examples or other post war aircraft (with different engines)
had 3-bladed props to cope with increased power.

Regards,
Herman

[Morgans[_2_]]

> I thought most wartime Ju-52/3m's had 2-bladed props.
> Possibly CASA examples or other post war aircraft (with different engines)
> had 3-bladed props to cope with increased power.

Long to short, what most people are discussing is whether the RC models had
the correct historic prop on them. What may be going on is what is
necessary for models to work well, not the ignoring of the proper props. <g>

When RC planes are done to high levels of historic accuracy, still, the
props are many times the wrong number of blades or the wrong diameter. When
it is being displayed, a historically accurate prop is put on, then changed
out before flying.

Reynolds numbers, and scalability of areas and weight does not allow most
engines to operate with a correct prop, unless luck comes to play, or some
extra complexity (gearing) comes into the application.

A 2 blade prop is more efficient than a 3 blade, and a 3 blade better than a
4 blade. Full sized Reynolds numbers don't hurt full sized applications as
much as it hurts model sized props. Still, the fact remains that 3 and 4
blade (and sometimes more) props are needed to harness the huge power
outputs of the full sized engines, without getting the diameter overly
large.

So, I guess what I am try to say, for those that are not very familiar with
RC scale planes, the builder was probably not ignoring what prop was used
for the full sized plane, but was just doing what he needed to do to have
maximum power output harnessed from the engine that was being used.

That's my take, anywho! <g>
--
Jim in NC