Which brushless motor?
 

I've been looking at brushless motors etc and can't help being a little confused.

Some advertise rpm per volt and others a Kv rating. Are these the same? e.g is a 2kv rating the same as 2000rpm/v?
How do I know how many amps the motor will pull and therefore which ESC I need?
How do I work out how many watts of power I have and need for a particular plane?
How powerful does the motor need to be to power a GWS E-starter or a GWS TM400?

Any help would be really appreciated.

Thanks..

RE: Which brushless motor?
 

Yes, kv is 1000s of rpm / volt

The only ways to know how many amps will be drawn are

* measure it
* read up on the motor specs and suggested configurations to get a fair idea
* get a program such as motocalc and work it out

The two most significant factors will be the pack voltage and the prop size. There are lots of other factors as well - get a demo of Motocalc to see for yourself

You determine watts by multiplying ‘volts’ times ‘amps’. Example: 10 volts x 10 amps = 100 watts

Volts x Amps = Watts

Both of those planes should fly well with a cheap Tower-Pro BM2408-21T, a cheap 18A ESC and something like a 1500 3S 12C pack. I used exactly that with an E-Starter. With an 8x4 GWS HD prop I could even hover it. It will fly slowly and fairly quickly. I've been completely happy with that power system. As my packs are quite large I put them under the wing in the radio bay and put the RX in the battery bay. You can fit the below motor straight to the stick with the below mount. Easy !

I used the same pack but the stock motor on the TM 400 and found it to be boring. I've sold it but the E-Starter is behind me as I type. It's a satisfying sports foamy and well worth the money. Not exactly a precise pattern plane but it will do quite a lot for the money. If you wanted to move on to say a warbird then all the gear would fit into something like a GWS Corsair. You could move the lot.

Here's the motor - [link]http://www.b*********.co.uk/?page=shop&action=additem&item=101[/link]
And the mount - [link]http://www.b*********.co.uk/?page=shop&action=additem&item=58[/link]

Don't forget that the pack has to be able to supply the current asked of it by the motor !

There's a good 'Power Systems' forum at RC Groups and a huge thread about the E-Starter in their Parkflyers forum

RE: Which brushless motor?
 

Thanks for some really useful advice.

RE: Which brushless motor?
 

I see that you are in the UK. Hadn't noticed before. That company that I linked to are really good. Ordered from them loads of times and they have been good for after-sales, delivery times and prices. I got the plane from Sussex Model Centre and the packs from www.aero-nuts.com who deliver in less than a week from Hong Kong. I've ordered several times from there as well.

PM me if you want to.