The right size and power

[FunCubParts]

Some of us tend to be obsessed with the "bigger is better" mentality, and the more horse power the better, but was the FunCub designed for a power system that exerts speeds of more than 30 or 40 mph? I personally hardly ever fly my FunCubs over about 20mph, but that's just my flying style (low and slow, touch and go). What is you preference? What does your FunCub perform the best at, and what kind of power system are you using?

[daesharacor]

My first FC was the RR version, so I had the stock components. I felt that it had more than enough power. For this next one, I'm going to only get the minimum power to keep the weight down. I'd like to restrict my available power so that the power to weight ratio is similar to an actual SuperCub. That way I can't get myself in to trouble and just power out of it.

[batouttahell]

We used the light power pack from Fun Cub Parts with our first FC, even though we painted the cub, adding weight, that light motor has plenty of power to pull it out of bad situations. We started with a 12 X 6 prop, very fast, have been using an 11 X 3/8 for a month. Have never tried a 13 X 4 on it. We are building another now, standard motor, not by multiplex, again the Fun Cub Parts pack, looks like we are both doing the same thing, but opposite.

[wrongway]

Hi. I flew RC planes in the early 80's. I've decided to get back into it and I found the Fun Cub and love it and want to build one. My question is will a Turnigy G10 810kv with a 13x4 APC style prop and a 2200 3s LiPoy be a good trainer setup to learn with? Looking forward to your replies
PS. I used eCalc to do some checking and it seems ok.

[vegasdave]

I have about 6 funcubs. Some are as light as I could make them with small motors and batteries to keep the weight down and some have big motors and big batteries and wood props and heavy landing gears and plenty of paint. Every one of them flies great. My favorites though have 3542 motors and 4 cell batteries. They fly plenty slow and still float, not TOO much difference from the lightest one yet there is a difference. The reason I like them the best is they will go straight up until they are to high to see, and do barrel rolls on the way. They fly inverted and can do outside loops at will. I mostly just fly low and slow and enjoy precision landings but the big motor cubs with wood props and big tailwheels and articulating landing gear with custom paint jobs look more real and are SLIGHTLY more fun to fly. I recently bought a Carbon Z Cub that has 3D capabilities and it has a 7 1/2 foot wing span. It doesn't quite have the power to weight ratio of my most powerful funcubs.

[cubcrafter60]

My original FunCub was built fairly stock and flew with the Multiplex recommended Hi-Max set up. It flew great and had plenty of power even with floats. I flew it every chance I got for about three months with just the normal scrapes and bumps but the first time my wife came out to watch me fly I crashed, bad (dumb thumbs)! The rebuild took about three months and turned out to be a pretty extensive conversion. Dispite gaining some weight the remaiden went well with the original power package. On the eighth flight (the day after the remaiden) I got into an unusual attitude (see full story in featured cubs section) and while I believe I did everything right to recover her but she just ran out of power, she stalled and came straight down through an Oak tree! I didn't touch the plane for about eight months but when I rebuilt it a motor upgrade was a priority. She (re)remaidened with a firewall mounted Turnigy D3536/8 1000KV Motor and a 12x6 APC e-prop and she's flying as good as ever. I also prefer low and slow but there's some comfort knowing theres a reserve of power available if it's needed!

Photos Top - My original FunCub    Middle - (Re)remaiden day    Bottom - Remaiden day    Sorry photos didn't post in the order uploaded.


Robin

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[kate66]

Can anyone explain the best newbie programming set up for the Multiplex BL 40 S-BEC brushless controller. The default settings seem mostly ok but I'd like to understand more about soft start v standard start and also the pulse frequency option (8kHz v 16kHz). My instructor didn't like the poor throttle response (like turbo lag) which is probably the soft start default setting).

[cubcrafter60]

Kate,

Soft start is primairly for helis to the allow them to spool up slower to prevent damage to the drive train and/or flipping the heli due to torque.

I wasn't real sure on the pulse frequency but this was the most understandable explination I could find, Thank's to Ron van Sommeren on RC Groups for the explanation:

PWM = Pulse Width Modulation

Unless your ESC is at full power, the ESC pulses (or chops up) the voltage to the motor. The wider the pulse, the more power it gets, 100% pulse width is 100% power. The frequency of these pulses can be 8kHz, 16kHz or 32kHz. Although the voltage to the motor is pulsed, the current to/in the motor is not pulsed. The 'smoothess' of the current depends in the motors inductance (the more inductance, the smoother) and the PWM frequency (the higher the frequency, the smoother). High inductance (e.g. outrunners) motors can do with 8kHz, low inductance motors (eg. slotless or ironless motors, Kontronik Tango) need 32kHz. Driving a high inductance motor with 32kHz won't hurt, but controller losses will be higher. So in your outrunner case, use 8kHz.

I learned something today.    Hope this helps!

Robin

[kate66]

Many thanks Robin. I just learnt something new too !