I'm currently trying to pick an ESC for my plane, which is a 36" span balsa CAP 232.

I have this motor: http://2dogrc.com/ecommerce/os/catal...20-p-1848.html

(xmotor 300b brushless 1220 kv) and I'm planning to run it with a 3c, 2200mah 11.1v Li-poly battery.

From what I can tell (it says this motor can take 6-8 cells, or 2-3 lipo), this battery will be fine with the motor (in terms of not frying it), is this correct?

I'm looking for an ESC that will match well with this, that has a BEC to power my radio gear. The motor max loading is 13A, and max efficiency current is 6-10a.

This is kind of where I get a bit lost at. Would a 25A esc be a good choice for this, or should I go higher/lower? I believe it needs to be sensorless. So many of the ESC's I've looked at online don't mention if they are sensorless or not, is there an easy way to tell? I don't know which specification of the motor I should be taking, and giving myself a bit of a buffer when choosing an ESC.

Finally, do most/all BEC's have a voltage stepdown circuit? i.e if I'm using an 11.1v battery, the BEC will step down my voltage to 4.8 or 6 so as not to fry my radio gear? I suspect they do have this but would like to check.

Many thanks in advance for any help with this.

I like the Thunderbird 18 from Castle Creations myself. It does not have as many programming options so it is cheaper than the Phx series.

http://bmkdesigns.net/product_info.p...roducts_id=103

The ESC will sort out all your power for the controls, no need to worry, if you can afford it get a 25A ESC its more versatile later on. How heavy is your CAP? The DualSky motors are nice but not that powerful, I got the 400B in my Fliton ICON (20 oz plane) and performance is okay only. Will turn a 10x3.8 prop at only about 7,200 RPM.

ANyways, I am using a cheap 18A ESC for my 400B, it serves its purpose and the ESC is only programable for brake on/off, the 2S/3S is programmed using a jumper switch.

Thanks, for the suggestions. the flying weight will be around 1 to 1.5 lbs. I'm using an 8 x 4 prop.

Are most esc's sensorless? I'm currently looking at a great planes 25a esc, are these a good brand?

thanks again guys.

Dude ... if the plane is 1.5 lbs then the 300B is not much performance, I mean my 400B on the 20 oz plane is already so so only. Also, you should try perhaps an APC 9x3.8 prop, will give you more thrust but not drawing much more amps.

With the stuff I'm putting in there I think it'll come out at around 1.2 lbs. But still that sounds like it'll be underpowered.

What motor would you reccomend then for this setup?

thanks!

Most speed controls today are sensorless if not all. I had a Great Planes speed control once and didn't like it as well as the Castle Creations controllers. Castle gve alot more programing options making them more flexable. That motor may work out for you but I would run a 10x4.7 APC prop on it. For $5 more I think I would get the 400b instead still using the 10x4.7 prop.

Thanks very much, that clears up the sensored/sensorless thing nicely.

I've been doing a bit of browsing and found this motor:

http://www.megamotorusa.com/Brushles...-15-4.htm?id=3

It's reccomended for a very similar plane to mine (36" cap 232), with similar power requirements. The only thing that I'm unsure of is this; my setup uses direct drive, this motor lists several direct drive applications but for the cap it lists a 2.5:1 gearbox with a 10x7 prop.

My question is, would this motor be a good choice (from what I can tell it would), and would I have any problems running it direct drive with a smaller/lower pitch prop?

Thanks again for all your help.

Core - for 3D fun I will say go for the Himaxx 2816 ... but if its only for aerobatics then go for the DualSky 400B, I got mine for the Fliton ICON and its okay with the 10x3.8 for 3D.

The best set up is always to go with an inrunner and gearbox, its most efficient. You can play with gear ratios and that makes it more versatile. For me I go with outrunners because in Malaysia it sucks trying to get pinions and spur gears.

You cannot use that Mega for a direct drive on your CAP, its only okay for those pylon planes, foam pushers or flying wings. The motor should only be turning something like a 5x5 or 6x4 and that is not what you want for your CAP, it will not haul your CAP at all like that. You need a gearbox to turn a 9x6/10x6 prop.

Hmm, if I can find one of those inline gearboxes (not sure on the correct name, the ones that screw on the end of the motor and are the same size as it), would that mega motor work well? I'm looking for performance somwhere between aerobatic and 3d.

Thanks again for the help with this.

Core - what you are looking for in performance is not what the DS 300 will be able to give you if your CAP hits 20 oz. Bets to go with the 400B at the minimum. Have fun!

Yup thanks to the helpful advice here I've given up on the 300. Seems like I'll need a 400+ sized brushless.

Am I correct in thinking that an outrunner doesn't use a gearbox because it has more torque?

An outrunner motor would fit in my plane much much better, can I sucessfully use a good 400 size outrunner, with direct drive and get good performance?

Yes, get an outrunner. I like the Himax outrunners myself never had a problem with them. If you go here they have the charts for the Himax motors www.bmkdesigns.net or send them an e-mail they are good with these motors.