[NSRCA-discussion] APC 18.1 x 10W props

Wed Nov 22 14:49:33 AKST 2006

Hi Mike,

I got to try the prop over the weekend and I really like it. You certainly
achieved your goals with this prop because I had to learn to fly a
completely different model. The flight speed envelope is very consistent and
slower compared to my previous setup. Unfortunately the weekend was very
windy which made flying quite challenging and I couldn't get my model dialed
in to my liking flying the slower speed. I did manage to get a flight in
when the wind was very light and I found this prop combination fantastic.
The down-line braking and the vertical pulling performance really impressed
me.

I also found it easier to make the back ends of all the Cuban 8's and
reverse Cubans round because the model flies a constant speed everywhere
therefore very little elevator work was required to keep the shape. 

I now have to learn to fly smaller because I was getting very close to the
time limit on most of my P07 flights. 

The 18.1 x 10W is definitely a keeper for me. Thank you for making this prop
available to all of us.

Regards,

Peter

P.S My DZ160 pulls this prop at 8150 RPM

  _____  

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Dr. Mike
Harrison
Sent: Thursday, 16 November 2006 00:23 AM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] APC 18.1 x 10W props

Peter,

I understand your concerns about the YS abuse.  It seems the OS 1.4 "doesn't
care", it just goes a slower rpm.  I have spent a few years learning mostly
by luck how to make the OS work.  I am quite pleased with it at this point.
I have more than enough power and minimal maintainence.

Mike

----- Original Message ----- 

From: Peter <mailto:pentagon.systems at bigpond.com>  Pennisi 

To: 'NSRCA Mailing List' <mailto:nsrca-discussion at lists.nsrca.org>  

Sent: Wednesday, November 15, 2006 7:48 AM

Subject: Re: [NSRCA-discussion] APC 18.1 x 10W props

Hi Mike,

Thanks for the reply.

Normally I would just fly the prop but I would like to try it at a comp on
the weekend. I just wanted to see if the engine would pull it because it is
a big propeller compared to what I normally use. 

I also mix my own fuel which has a mix of LV and HV oils. Unfortunately I
sacrifice some power compared to running all LV oil (similar to CP 30% heli)
I also run only 25% nitro to keep the fuel bills down. I wanted to determine
whether I had to change my fuel to overcome the greater load. We have very
hot and humid conditions where I live. A overloaded YS in our conditions
won't last too long. From my experience a DZ turning under 8100 will
struggle to produce good power in the air.

I will mix up a batch of 30% fuel and give it a try. I am really looking
forward to trying it as most people think it is the best prop they have
used.

Regards,

Peter 

  _____  

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Dr. Mike
Harrison
Sent: Wednesday, 15 November 2006 23:31 PM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] APC 18.1 x 10W props

Peter,

Hi,

I am Mike Harrison, I worked with APC to develop these props.  Let me tell
you the goal of the prop design.  It is to fly at a moderate to slow
constant speed under the noise limit but with good pulling performance.
Therefore, regarding the rpm, the 8000 is about ideal for that prop, turn it
much more and you will be above the noise limit.  

I find it interesting that you determine whether a prop is adequate by first
tacking it.  I would think you would fly it first to see if it was adequate.
I would encourage you to do that first.  The OS 140 turns it about the same
and it flies very well. 

The whole purpose was to develop a prop that would fly at a deliberate pace
at about 150 meters to compete with the electrics.  

There is also an 18.5x9.5 which I fly and it turns about 7500 rpm.  I like
it better than the 18.1x10.  I am working on a 19x9 at the moment.

Good luck

Mike

From: Peter <mailto:pentagon.systems at bigpond.com>  Pennisi 

To: 'NSRCA Mailing List' <mailto:nsrca-discussion at lists.nsrca.org>  

Sent: Tuesday, November 14, 2006 5:48 PM

Subject: [NSRCA-discussion] APC 18.1 x 10W props

I recently purchased some 18.1 x 10W APC props for my DZ160. Apparently
there appears to be another version 18.1 x 10.1.

Could someone please tell me the difference between both?

I tried a quick ground run on this prop (stock) this morning but could
barely get 8000 RPM from the engine. I will take advice from a member on
this list and lop 1/4inch of each blade. What RPM readings are people
getting who are using either of these props on a YS DZ160 engine?

Regards,

Peter 

  _____  

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