[Dangaras]

Originally Posted by flytwice

I fly my 6 foot Unionville Beaver using a Scorpion 3014-1040 on a 3S 2800mah battery. The planes only weighs 4lbs,6oz RTF. Motor puts out 385 watts on a 11/6 Apc (12/6 cut ot 11). Flies exactly as a Beaver should, 45 degree climb outs, 1/2 throttle level flight, full throttle loops. For floats I use the 11/5.5 Apc on 4S for 700+ watts (used sparingly for takeoff).
If you wanted to do it all on 3S, use the 3020-12 Scorpion with 12/6 for 575 watts, with 3200 to 3600 mah 20c battery, another great combo.
These planes are not 3d, over even acro, so don't need the huger power, even for floats that most people think they need.
My plane would fly very well with a 25 nitro, and the 40 size would be ridiculous, wings probably wouldn't stay in place very long!!
Hope this may be of some help flytwice

Here are some electric power to weight guidelines.


* 50-70 watts per pound; Minimum level of power for decent performance, good for lightly loaded slow flyer and park flyer models
* 70-90 watts per pound; Trainer and slow flying scale models
* 90-110 watts per pound; Sport aerobatic and fast flying scale models
* 110-130 watts per pound; Advanced aerobatic and high-speed models
* 130-150 watts per pound; Lightly loaded 3D models and ducted fans
* 150-200+ watts per pound; Unlimited performance 3D models

[flytwice]

Hello Juice90: Just like the performance chart Dangaras put up, a Beaver does not need the BIG power so many seem to think is necessary these days. Remember, you want it to fly like, well, a "Beaver".
The Unionville 6 ft is a lightweight kit, but made for glow, take advantage of lightening techniques such as replacing the solid vertical tail and elevator with stick frames, remove extra 1/4 crosses in front, then drill as many 3/4" holes as you can around structures, like the firewall etc. 80-90-watts per pound makes them fly like a champ! I replaced my original motor with an upgrade, went from 325 watts to 385 watts. Actually sacrificing flight time with upgrade, and no real advantage in the Beaver.
I just recently completed another 6 ft'r, bashing a radial into a Turbo, it weighs 5lbs,10oz RTF. 3020-1110 Scorpion, 10/7/3blade MAS prop makes 575 watts/ 3600/20C battery. Takes off briskly at 5/8 throttle, will climb almost vertical, really not very scale like at all. The Turbo would fly just fine with the smaller 3014-1040 ( lighter, cheaper, less amp hungry). FWIW flytwice

[Dangaras]

Originally Posted by flytwice

Hello Juice90: Just like the performance chart Dangaras put up, a Beaver does not need the BIG power so many seem to think is necessary these days. Remember, you want it to fly like, well, a "Beaver".
The Unionville 6 ft is a lightweight kit, but made for glow, take advantage of lightening techniques such as replacing the solid vertical tail and elevator with stick frames, remove extra 1/4 crosses in front, then drill as many 3/4" holes as you can around structures, like the firewall etc. 80-90-watts per pound makes them fly like a champ! I replaced my original motor with an upgrade, went from 325 watts to 385 watts. Actually sacrificing flight time with upgrade, and no real advantage in the Beaver.
I just recently completed another 6 ft'r, bashing a radial into a Turbo, it weighs 5lbs,10oz RTF. 3020-1110 Scorpion, 10/7/3blade MAS prop makes 575 watts/ 3600/20C battery. Takes off briskly at 5/8 throttle, will climb almost vertical, really not very scale like at all. The Turbo would fly just fine with the smaller 3014-1040 ( lighter, cheaper, less amp hungry). FWIW flytwice

I use these guidelines for all of my models, then to be safe I up-size power by 25% to give myself an acceptable safety margin, just in case.

[flytwice]

Hi Dangaras: While I agree with most of what you have said, I have seen far too many people put in way more power than they need, especially on planes designed to be flown scale (ie: Pipers, Taylorcrafts, Beavers etc) and find themselves with a heavy plane that will only fly like the devil.
IMHO, any plane designed to be flown "on the wing" should not be over powered.If guys spent more time thinking about how the plane should fly, instead of how "fast", or how much "power" they can brag they have, or trying to make a scale plane hover like 3D stuff, they'd have a better plane they would enjoy more!
I'm sure you have seen these guys, flying a Cub at 60 mph,ripping the wings off trying to pull out of a loop, lightest landings result in broken landing gear etc, etc. These are the people that put a 40 size electric in a plane designed for 25, then wonder why it came apart in the air!
Make it as light as practical, power it with adequate motor/battery combo, then fly the plane as it is intended to be flown.
I have flown my 72" Radial Beaver on 50 watts/lb, it handled anything a real Beaver would do, no excess power to get out of trouble, then moved to 75 watt/lb, excellent flyer, long flight times, more than adequate power for takeoff. Recently got the new improved version of the same motor, it easily puts out 385watts = 89wt/lb, results, it takes off faster (not scale), climbs quicker, consumes more amps, shorter flight times on the same prop. Going to prop down to 325 watts, much perferred! flytwice

[Dangaras]

Originally Posted by flytwice

Hi Dangaras: While I agree with most of what you have said, I have seen far too many people put in way more power than they need, especially on planes designed to be flown scale (ie: Pipers, Taylorcrafts, Beavers etc) and find themselves with a heavy plane that will only fly like the devil.
IMHO, any plane designed to be flown "on the wing" should not be over powered.If guys spent more time thinking about how the plane should fly, instead of how "fast", or how much "power" they can brag they have, or trying to make a scale plane hover like 3D stuff, they'd have a better plane they would enjoy more!
I'm sure you have seen these guys, flying a Cub at 60 mph,ripping the wings off trying to pull out of a loop, lightest landings result in broken landing gear etc, etc. These are the people that put a 40 size electric in a plane designed for 25, then wonder why it came apart in the air!
Make it as light as practical, power it with adequate motor/battery combo, then fly the plane as it is intended to be flown.
flytwice

I agree, too many people overpower the bird and tear it apart or end up with decreased flight times because of the added weight. Sign of poor piloting and design for scale models, IMHO.

Just because you have the power does not mean you have to use it, like most aircraft, the engines can deliver more power than is necessary which results in the ability to overfly the aircraft or use it as necessary to get out of trouble.

I do like flying scale, but every now and again I enjoy pushing a model to do mild aerobatics for the hell of it. Sometimes the motor/ESC/battery package cost and weight combination force the purchase of more power than required.

I prefer Turnigy SK series motors over all the others, but I can't always get the correct power to weight motor and ESC, better to go larger than smaller.

[flytwice]

Hi Dangaras: I totally agree, it is very difficult sometimes to find motors that fit the specific needs. It must be 110% harder for someone new to the hobby. Its still confusing to me after 2 years. Not only do you have to contend with finding the right combo, you have to read between the lines, and make sure what the mfg are telling you is not a big crock of s...t!
That includes the airplane mfg too! Motor mfg tell the public their motors are 98% efficient- when they are really 60, aircraft guys tell you the plane will be 5 lbs, ends up being 7+, with thier recommended systems.
I have a couple of Turnigy's on their way as we talk. Other club members are having good results.
I also really like the Scorpion Motor lineup, but even they don't have all the combo's. They will make you a custom wind if your willing to wait 6-8 weeks!

When I started buying electric motors, I believed all the ads, bought accordingly, ended up with several motors not suited for purposes, burnt some up, took a hammer to a couple (cheaper than sending back).

Now I start out with a look at the models suggested AUW, then pick a propeller size for that model, whether it 2-3 blade, then look at the plane type and motors that can provide watts ( I use 100watts as stepping stone). If its a sporty plane I'll go higher watts, but matching the right size prop has proved the most satisfactory. I hate bigger planes with tiny little props screaming away to get the necessary power. I always use either scale size or larger, they look better and definately perform better!
It is a real learning experience to be able to pick the right combos, still learning. Thanks for your input!! Hope our conversation helps others- flytwice

[Fast Guy]

I converted a Sig 1/5 scale J3 Cub to electric and equiped it with floats much like you want to do with your Beaver. The plane has an AUW of just over 7lbs and the floats add another 2lbs. I used a Rimfire 50-55-500 (.80), Castle Creations Phoenix 80, Xoar 16x6 prop and 6s 3200 30c Flightpower battery. I'm getting about 1100 watts at full throttle. Performs very well, scale flight at 1/3 throlttle and has the power to save your butt when things go wrong.

Sig 1/5 Scale J3 Piper Cub Kit on Floats