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Old Feb 14, 2012, 02:03 PM
LiPo-Sucker & Airframe EMT
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Charlottesville, Virginia, USA
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Originally Posted by turboparker View Post
In the article, Boucher specifically discussed RC aircraft scale speed - not moviemaking. Furthermore, he is addressing the aspects of scale speed independently, and hie final analysis is all-encompassing. Scale-appearing speed = the square of the scale factor. Any other relationship will not appear to be scale. Believe what you wish, but this is the accepted method of determining scale speed.
Joel

This was debated on RCG >10 years ago: http://www.rcgroups.com/forums/showthread.php?t=5221

Here's a calculator for converting scale and real speeds:http://webpages.charter.net/sinkwich...cale_speed.htm

An interesting article: http://www.djaerotech.com/dj_askjd/d...calespeed.html

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Old Feb 14, 2012, 02:14 PM
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Originally Posted by electricrc68 View Post
it probably would add a good amount to the price. the reason why i like the brushed ones better is the speed. i don't have enough space for a brushless plane to be zipping around.
That's always my thought. I never understood the fascination with speed (at least not with the SU-26XP). I like to do patterns and aerobatics in as small a space as humanly possible.
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Old Feb 14, 2012, 03:16 PM
Gopher huntin' stick jockey
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Originally Posted by BryanEW710 View Post
That's always my thought. I never understood the fascination with speed (at least not with the SU-26XP). I like to do patterns and aerobatics in as small a space as humanly possible.
I never understood why it is a problem at all. Throttle-management solves this for the most part. Regarding the Spit - it's a hot-rod warbird. It's supposed to be fast @ WOT.

Joel
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Old Feb 14, 2012, 03:19 PM
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Originally Posted by turboparker View Post
I never understood why it is a problem at all. Throttle-management solves this for the most part.
I think it's more a function of wing-loading. I prefer to have the extra thrust to having top-end, if that makes more sense.
Quote:
Originally Posted by turboparker View Post
Regarding the Spit - it's a hot-rod warbird. It's supposed to be fast @ WOT.
Understandable. This might not be the bird for me, given that. Maybe I ought to just find a T-28. Problem with that one is that doesn't roll nearly quickly enough for my tastes.
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Old Feb 14, 2012, 04:07 PM
Gopher huntin' stick jockey
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Originally Posted by BryanEW710 View Post
I think it's more a function of wing-loading. I prefer to have the extra thrust to having top-end, if that makes more sense.
Understandable. This might not be the bird for me, given that. Maybe I ought to just find a T-28. Problem with that one is that doesn't roll nearly quickly enough for my tastes.
Yes, it makes sense. For me, it depends upon the airframe. I usually prop draggy airframes for thrust, and typically I prop slippery airframes for speed. For instance, my Besast 3D is propped for thrust, while my UMX Sbach is propped more for speed.

With my larger, true-scale ships I try to prop them to fly at scale-appearing speed, when feasible. For instance, my 1/4-scale Super Cub is propped for a 75% cruise of ~50 MPH, or ~50% of scale speed. Which makes it nearly indistinguishable from the full-scale in flight - given the square of the scaling factor rule. In fact, on a number of occasions over the years, I've had full-scale pilots drive like mad down the field road to get to the field, thinking that a full-scale Super Cub was attempting an emergency landing - only to realize that it was a 1/4-scale model practicing scale takeoffs & landings! The looks on their faces were priceless!

Regarding this bird - I doubt that it will be any faster than the current UM warbirds - given that it uses the same motor & gearing, but with more weight & a 4-blade prop. I'm thinking that it will probably be faster than a stock UM F4U, but slower than a stock UM P-51.

Joel
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Old Feb 14, 2012, 05:01 PM
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Originally Posted by turboparker View Post
Regarding this bird - I doubt that it will be any faster than the current UM warbirds - given that it uses the same motor & gearing, but with more weight & a 4-blade prop. I'm thinking that it will probably be faster than a stock UM F4U, but slower than a stock UM P-51.
Hmmm...maybe I am interested, given that!

I always thought my XP was plenty fast, especially considering its tendency to change direction pretty instantaneously if you weren't paying attention. Do the UM warbirds do this as well? I really only have experience flying a couple friends' T-28's for a grand total of about 3 flights.
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Old Feb 14, 2012, 05:39 PM
Fly, be free! (splat)
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Yes, the UM warbirds change direction on a dime, even when you don't expect it because of turbulence. . The Spitfire is going to have AS3X to smooth out the unexpected variety- I'm really interested in this, plus I quite like the Spitfire.
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Old Feb 14, 2012, 05:51 PM
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Are some of you guys honestly complaining that this may be too quick and thus not scale?

Lol

Boo hoo, wimper, wimper

The more power/thrust/speed the better.

Like Joel says

Throttle management!!!!!!!!!!!!!!!!
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Old Feb 14, 2012, 06:09 PM
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Originally Posted by jdwolters View Post
Yes, the UM warbirds change direction on a dime, even when you don't expect it because of turbulence. . The Spitfire is going to have AS3X to smooth out the unexpected variety- I'm really interested in this, plus I quite like the Spitfire.
It's not really that I'm worried about instability. It's more that the plane simply cannot be flown hands-off. With my XP, I'd be flying straight ahead one minute, look down, and be rolling off into a spin the next (the plane is VERY susceptible to tip stalls)

Quote:
Originally Posted by Razors edge 29 View Post
Are some of you guys honestly complaining that this may be too quick and thus not scale?

Lol

Boo hoo, wimper, wimper

The more power/thrust/speed the better.

Like Joel says

Throttle management!!!!!!!!!!!!!!!!
For me, it's not a matter of speed, it's a matter of thrust.
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Old Feb 14, 2012, 06:30 PM
Gopher huntin' stick jockey
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Quote:
Originally Posted by Razors edge 29 View Post
Are some of you guys honestly complaining that this may be too quick and thus not scale?

Lol

Boo hoo, wimper, wimper

The more power/thrust/speed the better.

Like Joel says

Throttle management!!!!!!!!!!!!!!!!
RE,

No worry about exceeding scale speed with the Spit. Going by the 'square of the scale factor' rule, scale speed works out to be ~60 MPH, given a top-speed @ SL of 320 MPH on WEP.

Speaking of throttle management - one thing I have never understood is why so many RC pilots fly wide-open throughout the entire flight. A large number of pilots even keep the throttle pegged on their downlines! With four-cycle engines, no less!! I cringe every time I hear that at the field.

Joel
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Old Feb 14, 2012, 06:36 PM
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Originally Posted by turboparker View Post
RE,

No worry about exceeding scale speed with the Spit. Going by the 'square of the scale factor' rule, scale speed works out to be ~60 MPH, given a top-speed @ SL of 320 MPH on WEP.

Speaking of throttle management - one thing I have never understood is why so many RC pilots fly wide-open throughout the entire flight. A large number of pilots even keep the throttle pegged on their downlines! With four-cycle engines, no less!! I cringe every time I hear that at the field.

Joel
One big goal of mine!
I love to fly right off the deck when I Sport/3D, and for some reason I have a big issue with the throttle and I've nailed a few planes into the ground at fast speeds?
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Old Feb 14, 2012, 06:52 PM
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Originally Posted by turboparker View Post
Speaking of throttle management - one thing I have never understood is why so many RC pilots fly wide-open throughout the entire flight. A large number of pilots even keep the throttle pegged on their downlines! With four-cycle engines, no less!! I cringe every time I hear that at the field.
Not I. I seldom fly above 60% throttle if I can avoid it, even during aerobatics.
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Old Feb 14, 2012, 07:07 PM
The Sweet Aroma of 92 Octane
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United States, PA, Downingtown
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i have to work on throttle management. maybe the mcx2 that im about to receive will help me learn throttle management.
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Old Feb 14, 2012, 07:12 PM
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I have a tendency to fly full throttle, but I gots a need for speed lol

No, depending on the plank, I use throttle management for different maneuvers, BUT its always good to have lots of pull out power, especially for fighting wind in these little guys
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Old Feb 14, 2012, 07:42 PM
Gopher huntin' stick jockey
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East Bethel, MN USA
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Originally Posted by BryanEW710 View Post
Not I. I seldom fly above 60% throttle if I can avoid it, even during aerobatics.
+1

Most of the time, I only use as much throttle as the maneuver requires, and go to WOT only when necessary. However, I typically set my planes up so that full-throttle is not required for normal maneuvers. Whether it is my car, audio system, computer, or my RC plane - I like to have plenty of headroom. For instance, my PA Extra 260 hovers @ 33% throttle, and can do any unlimited aerobatic maneuver without ever going above 60%. I used an OS 1.60 flat-twin 4-stroke in my 1/4-scale Super Cub, and then propped it for a 75% cruise, which is a common cruise power-setting for full-scale piston-engined planes. With a Dynathrust 20x6, it can hang on the prop for awhile, if I wish. That engine saved the plane when I hit a tree on approach one day. A lesser engine would have likely stalled trying to cut the branches, and would surely not have had enough power to recover at such a low altitude, even if it didn't quit.

Why I like 'headroom' in my RC planes (pardon the OT video):

1/4-scale Super Cub hits tree! (0 min 58 sec)


Back to the Spit. If it is lacking headroom, a Nine Eagles Bravo SX motor will fix that. With a top-quality battery, it's good for nearly 40% more power than the stock motor - with the same external dimensions, so it fits the mount. Just install the PZ pinion & connector & you're all set. Sorta like pulling the small-block out of a Chevelle & dropping-in a 427.

Joel
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Last edited by turboparker; Feb 14, 2012 at 07:47 PM.
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