RC planes are so much heavier!

batjac wrote:RC planes are so much heavier than control line planes.  My Black Widow powered Baby Ringmaster is 4.5 ounces.  My Black Widow powered Q-Tee is 17.5 ounces.  And that's not overweight.  The original plans/article for the Q-Tee has a recommended weight of 16-20 ounces.

The Obvious Mark

Yea.. but try flying that CL Baby Ringmaster at even 1/2 the weight (8.7oz.) of your RC Q-Tee. There's such different dynamics at play between the two types of controlling. I believe that a  conventional control-line model airplane requires a lot more "thrust" to be able to perform aerobatics.. than does a comparable radio-control model airplane. I'd also bet that a control-line airplane burns much more fuel than a radio-control model airplane.. if the fuel economy could be measured with a degree of accuracy.

https://rcplanes.online/cg_wing.htm

Link above to calc. wing loading.

Speed Plane:
TD .051 Nano II has 75 sq. in 3ch 8.1oz RTF
15.55 oz/sq. ft. (glides in nice and steady)

My inclination is to keep 1/2A weights below 14 oz/ft² for RC.  My avatar, the Honker, comes in at 11.6oz/ft² and will fly out of my hand with a gentle push.  

Although the newer Spectra line is both significantly lighter and smaller in diameter than the older Dacron line, it still adds considerable drag to the C/L planes that the RC planes don't have to overcome.  Consequently, model weight being hauled by the engine may appear much "greater" than the actual physical weight of the plane itself.

Wing loading is only one aspect of how well a plane flies. Aerodynamic forces including the lift are proportional with speed on the 2nd power. If the plane generates too much drag because the wings and fuselage are too thick, and the speed of the plane is reduced, it will soon stall when the engine stops and the plane glides and decelerates and become difficult to control.

I am still astonished at how long my Tigercat RC pylon racer (https://www.coxengineforum.com/t16635-tigercat-rc-pylon-racer-build-project?highlight=Tigercat) , weighing more then 20 ounces and pulled by a 049 TeeDee glides with the engine stopped, thanks to its otherwise slender design..I am not at home to check the wing loading but it is near the upper end of recommended range for sure.

About all of mine are

Hi All,
Here's my take:
R/C=an Orange. C/L=an Apple. Or vice versa !
My 21oz Honker flew great. Hauling old Heathkit r/c gear. All weather. Could thermal with it.
My 6oz C/L 'Pirana' with same power flies great on 40ft lines.
Ask Aspeed about line drag !
Just have fun.
I like 16oz/sq.ft goal for r/c < .25. All weather flying.
Take care,
Have fun,
Dave

I guess a lot of a C/L plane’s thrust is spent on keeping the lines tight and the lines cause a lot of drag too. Hence the need of more horsepower per ounce, even if the wing load may be similar.

What kind of equipment do you have in it? Radio gear today is so much lighter than when it was published.

When I built my R/C planes, I didn't have a weight scale but didn't need one. If you built and equipped per plans / instructions even with then standard servos & battery pack, it would fly as intended.

Q-Tee was designed to haul then standard R/C flight pack. I had Dunham Bantum mini servos & lighter 225 mAh 4.8 V nicad batteries, so I was within limits being lighter, flew well under Golden Bee power.

Actually, I take that back. I did have a small handheld balancing beam manual postal weight scale, it provided a confidence check.

Regarding drag of the lines for half-A C/L, the 30 feet of Dacron, I remember that once my 20" Sterling Beginners Fokker E-III Eindecker profile with Babe Bee engine quit, it would just sort of fall out of the sky. It immediately lost most of its forward velocity, from about 5 feet up would sort of mush in not even making a quarter circle. It was probably as light as Mark @getback 's.

The larger plane, Ringmaster .35 S1, would gently glide for at least 3/4 of a lap. If I whipped it a little, I could extend the glide.

The R/C's, all the ones I built, they weren't super draggy but weren't super streamlined either. Still, they had a decent glide slope, not like a glider, but still reasonable. I just had to make sure I kept a reasonable glide slope not to stall it.

The rudder only jobs, they were in essence trimmed like free flights anyway. I just made sure that I used gentle turns and killing any stall caused by accelerating during turning (tends to nose down) by kicking opposite rudder.

I got to where I could land a dead stick single channel within ten feet of me.

GallopingGhostler wrote:When I built my R/C planes, I didn't have a weight scale but didn't need one. If you built and equipped per plans / instructions even with then standard servos & battery pack, it would fly as intended.

Actually, I take that back. I did have a small handheld balancing beam manual postal weight scale, it provided a confidence check.

This is the scale I had back when I originally built the Q-Tee, a four ounce postal letter scale:






The Goin' Postal Mark

balogh wrote:
I am still astonished at how long my Tigercat RC  pylon racer (https://www.coxengineforum.com/t16635-tigercat-rc-pylon-racer-build-project?highlight=Tigercat)  , weighing more then 20 ounces and pulled by a 049 TeeDee glides with the engine stopped, thanks to its otherwise slender design..I am not at home to check the wing loading but it is near the upper end of recommended range for sure.

When the engine cuts at 130+ mph... I'm sure that a 1/2A pylon racer is going to glide pretty well/far.. (sorry Andras.. I'm just messin' with ya'   )

Roddie it flies much slower than that. The glide is very stable even at landing by the time the plane has decelerated.

Yes, RC airplanes do tend to be heavier. I also have a p-61 black widow

RC planes are so much heavier?

Parkzone T-28 foam electric (w/battery) four channel R/C, 16" wing 1.33 oz Vs. Home-built C/L w/ Cox .049 foam board/balsa 17" wing 4.69 oz.





It's all about that lump in the nose.   and modern day electronics.

The lowest weight 3ch for me thus far is a TD .049 / throttle sleeve @ 6oz less fuel.
A redesign in material use and slim up could yield a 3ch @ 5.3oz

It is possible to build a 4.8oz 2ch with a reed .049
Example 47.8g for the reed BL leaves 3.02oz for frame and 2ch gear.