eliav-RCU

My Feedback: (1)

OK!!! Where to start...


Everyone is talking about speed here and the more sweep the more speed... Well I am building a great planes patriot as of now and am noticing that the great planes F-15 has more sweep that the patriot does..... If it has more sweep than why do people say that patriot is faster....

Can you guys please clarify this up for me please....

O and has anyone ever tryed to not put any landing gear on the patriot and or F-15 and just using a trolley or something like that to get it moving for take off...

mr_matt

My Feedback: (10)

Look at racing planes, most have little or no sweep and they are very fast.

The GP F-15 is relatively high drag especially compared to the patriot. That is really where the speed difference comes in


As for a takeoff dolly, it can be done but requires fairly careful design and technique.

For speed the current favorites seem to be the whiplash, diamond dust, etc.

AKMac

My Feedback: (1)

I'm sure someone like Ollie can tell you better then I, but I'll try to explain to the best of my knowledge.

I've found it common that people think that the more swept and stubby a wing is, the faster it goes. In fact a properly designed high ratio wing like a glider is sometimes a faster wing then a short stubby wing that is swept back 60 degrees, not to mention more efficient. The reason most full scale speed demons like a F-14 have a swept wing is so the wing isn't in the shock wave produced by the planes nose in supersonic flight.

In our models that reach a top sped of maybe 220+mph you don't need a swept wing to go fast. Just look at the Q500 and QM 40's. Q500's have a straight wing just like a trainer, and QM40's just have nice high aspect ratio tapered wings.

What truly decides how fast a plane goes is basically how much drag it has, the choice of airfoil, and what is powering it.

Just because something looks fast doesn't mean it is fast.

banktoturn

For subsonic flight, wing sweep itself does not do anything to increase top speed. As AKMac says, drag is the issue. Having said that, the minimum drag configuration for top speed will end up being a low aspect ratio wing, not a high aspect ratio wing. You can't get much lower aspect ratio than Diamond Dust, Whiplash, and the other fast deltas being flown these days. What clouds the issue is that all of the fast planes also need to turn well enough to fly pylon, or combat, or just to stay in range. The fastest plane, if it didn't need to maneuver, would indeed end up having small, low aspect ratio ( stubby ) wings. If it needed to maneuver well, it might end up having a highly swept wing, so that it could generate lift at high angles of attack, although low aspect ratio wings are pretty good at that anyway.

banktoturn

Cyclic Hardover

My Feedback: (3)

The Patriot will keep right up with the F20 Tigershark. Hint-Jett.50 and it will scream.

Jackjet

My Feedback: (1)

[QUOTE]Originally posted by Cyclic Hardover
The Patriot will keep right up with the F20 Tigershark. Hint-Jett.50 and it will scream. [/QUOTE


You want it to go REALLY fast ? -just cram a piped Nelson .96 in it............


Jackjet

Razor-RCU

My Feedback: (50)

S Jett 50, Jett 90, Piped Nelson 96? (Does that exist?) I love this forum!

I get a YS-45 and a Rossi 45 and feel like a big-shot, until I read these posts and my mouth starts watering, and my wallet runs and hides ...(I have 1 Patriot ARF, and a KIT on the way..)

Please show pics of these things >>Patriots and power-plants!
It motivates me..

Later,
james

Jackjet

My Feedback: (1)

James,

the Nelson.96 is real-it is the same engine BVM uses in his ducted fan.-check it out-bvmjets.com
Jackjet