View Full Version : Brushless For Cox .049

Balsa Shavings
02-13-2006, 04:47 AM
Ok: Here's the scoop. I'm in the process of building a Waco SRE. The plans call for a Cox .049, that little screamer is out. I live next to horse farms, and them hay burners are very uppity about noise. I would hate to be the cause of somebody getting tossed off one of the beasts. So I need some recomendations on a suitable replacement. Brushless motor, battery, ESC. I want good flight times, be able to take off the ground, and some mild aerobatics, and at the same time, don't want my wife to have a fit about the cost.

Keep the Faith: Johnny

02-13-2006, 04:55 AM
Some info about the plane would be needed. For example, wingspan, weight etc. Generally a good 400 sized brushless would likely fit your needs power wise unless the airframe is a brick!

Balsa Shavings
02-13-2006, 05:21 AM
Top wing 36"
Bottom wing 24"
Weight Less than 20oz

02-13-2006, 12:36 PM
I broke and rode horses many years ago.

If you want to stay friends with your neighbors try to stay away from the horses all together.

They don't like anything strange and a model airplane of any kind will spook them. Been there, done that, have the broken bones to prove it.

We crash from time to time and the cows walk up and look at the remnants. Our field is on the edge of a cattle ranch. The property accross the county road is being developed.

Our new nieghbor has made the statement that any airplane lands on his property it is his, he is tired of our craft spooking his horses. He has two at the moment. One flyer got confused and the other had radio problems.

One of our flying buddies explained to the neighbor that he doesn't own the air over his place, that was proven in court.:rolleyes:
That was a big help.:rolleyes:

By george:)

02-17-2006, 07:25 AM
They don't like anything strange and a model airplane of any kind will spook them. Been there, done that, have the broken bones to prove it


That's surprising - perhaps USA horses are more nervous (I am from the UK)? I - and my clubmates used to fly next to a field in whihc several horses from th elocal riding school lived. Occassionally they would wander over to the fence to have a closer look at our goings on, but most of the time they simply ignored us - and this was in my IC days, not electric.


Matt Kirsch
02-17-2006, 03:07 PM
It could be the genetics... Growing up on a dairy farm, I do know that in an overzealous attempt to breed the "perfect" dairy cow, genetics companies have introduced many undesirable characteristics into the herd, probably through inbreeding.

Then again, American "horse people" are a different breed unto themselves for the most part... Many of them are just plain overzealous, overparanoid, overprotective... of the horses. The kind that if their kid gets thrown, they check if the horse is okay... Not saying they're all like that, but the kind that freak out because their horses looked up when the airplane went by, are.

Matt Kirsch
02-17-2006, 03:10 PM
Oh, and for the conversion, a nice "400" designated brushless motor on a 3S LiPoly, propped to draw 12-15 Amps would make a good power system.

Something like the Eflite Park 400 outrunner with a TP1320 or Kokam 1250 3S pack. Maybe the AXi 2808/34.

02-19-2006, 02:03 PM
I disagree with the "400" on your plane. The Waco is a biplane, right? Lots of drag with that model and could be underpowered. I would recomend at least 200watts, something like the e-flite Park 480 outrunner on a 10x7 prop. Thats what I'm running on my scratch-built (my own design) park flyer Cleveland Air Racer. I also had to upgrade my LiPo pack to a 2700ma three cell. Full throttle is 20amps with static thrust of 26oz. All Up Weight is 27oz.:D

02-19-2006, 03:42 PM
I honestly don't think that a 400 brushless would be a problem. I have a Scorpio Miss Chief that weighs ~23 ounces and it flies well on a geared SP400 so I'd expect a nice outrunner to fly better.

02-20-2006, 05:39 PM
I'm building a Kadetito from plans which was listed as a gas engine 049 - 09 or electric with a 035 cobalt (whatever that is?) and will use a Castle Creations 25, eflite Park 400 outrunner and a 10x7 prop. 10amps max with 11.1v gives 111watts. Here's the important stuff - 16oz all up weight including battery by careful selection of balsa weight and thicknesses! Should be a nice relaxing flyer at 1/4 to 1/2 throttle. The rest of the power is for windy days! Specs are: Wingspan of 36in, Wing area of 270 sq in. Stall speed of 11.7mph with a wing loading of 8.5 oz/sq ft. May leave this one three channel. Oh yeah, I put a rubberband suspension landing gear on it. It comes off for hand launches.

Matt Kirsch
02-23-2006, 03:53 PM

Sorry to be late to rebut, but rebut I must :)

A 400 brushless on 3S drawing 12 Amps is 120-130 Watts. We're looking at a plane with an AUW of <20oz. Even assuming the plane will weigh the full 20oz, which it probably won't, that's still 80 Watts per pound.

It's a slow, draggy bipe. We'll be using a large-diameter prop at a low RPM, so there will be quite a bit of efficiency gained there to compensate for the extra drag. I'm also assuming that we're not looking for 3D performance here. On 80 W/lb, with a good-sized prop, the plane's gonna be able to loop from level flight.

200 Watts will work, but it will be overkill.

03-06-2006, 10:23 PM
have a 43" D7, Richard Meixweall free flight plans, covered @ 16oz. minus wheels, servos. what electric motor and battary power do I need? am totally ignorant-- ex fuel and gas man. dick stamm

03-06-2006, 10:52 PM
Eflite Park 370 outrunner, Castle Creations Pheonix (10? I think?) Lipoly 11.1v 1200ma or so depending on the room inside the fuse. Batt dimensions can vary, so be careful. Should fly for 20 min or so with a 10x4.7 prop. Enjoy.

PS - The Kadetito flys for about 25 - 35 mins on one battery. Takes off from my hand at 3/4 throttle or ROG in about three feet! Nice easy flyer at 1/4 to 1/2 throttle.

03-07-2006, 04:51 AM
thanks, will check them out. plenty of room available. dick

03-07-2006, 05:27 AM
A S400 geared would do fine on a 3 footer- even a draggy one. My Mischief bipe was about that size and it did very well on a 3.3/1 gear and a 3s 1500ma Kokam lipo with a 7.2v S400. Of course they rattle a lot geared (great acoustics for a bipe)... then theres nothing like that 'reserve power' on a brushless! :D The wife will love your $10 motor if you go with the S400!!


PS: I don't know much about horses being finicky but we got stampeded one day in PA by some Flying W longhorns on our hang glider training hill in a pasture. Just like in the movies- rumble rumble - and a hundred heads appeared over the hill- straight for us! They turned at the last moment and went down the hill! Beef with Attitude!

Rag- Always helps to have the ruminants check the remnants! :D

03-08-2006, 10:38 PM
OK, no gears, no messin around. Instal an AXI 2212/26 and run a 9X6 to 11X4.7 Prop and a 3 Cell LiPo. It's quiet and will pull the wings off of it if you want to....

03-10-2006, 03:06 AM
OK, no gears, no messin around. Instal an AXI 2212/26 and run a 9X6 to 11X4.7 Prop and a 3 Cell LiPo. It's quiet and will pull the wings off of it if you want to....
Well of course we want to pull the wings off it! There's just something about a parabolic ballistic trajectory! ;) Good call, Top. I am stunned by all the good motors out there! A Speed x00 will never again lay my gliders low.

Yank with care!


I got to hear an unmuffled .049 last yr (after decades) when a buddy stuck one on a pod atop a Gentle Lady. NO WONDER we got kicked out of town back then! They are the VERY DEFINITION of OBNOXIOUS! :D