Matching Motor to ESC rating

[Adrian Smith 1]

I was looking at various motor and ESC combos, comparing to what I have which has prompted this question.

I have the DualSky 50-60cc equivalent motor like this one:-

**LINK**

I bought the recommended DualSky matching ESC to use with motor which is this:-

**LINK**

However, I am not sure this ESC has sufficient rating to cope with the motor as similar set ups I have looked seem to use 160HV and above for the ESC. The weapon of choice seems to Castle Creations 160HV (or as some call it Castle Cremations!). Presumable using the Dualsky ESC would detract from the motor performance if the rating is not quite there. Any thoughts?

[Frank Skilbeck]

Adrian, it all depends what prop you plan to use, looking at the motor spec the Dualsky ESC seems a good match, the CC 160A just has a bit more head room. Motor performance should be the same on both ESCs.

If you post your prop size and proposed batteries, I can run this through Ecalc and let you know the predicted performance figures.

[MattyB]

As long as you are operating at below the rated current of the ESC it should not make any difference to performance - it's the prop and the Kv that defines the load, not the max amp rating of the motor. My rule of thumb is no less than 10% headroom at full throttle, so on that ESC with a fully charged battery and the motor and prop combo of your choice I would not want to seeing a wattmeter reading of any more than 130-13 = 117A. Let Frank run the numbers for you and you will be able to tell whether your existing ESC will be suitable.

[MattyB]

For further information check out the list of sticky threads to help with your electric powertrain here...

Edited By MattyB on 07/03/2018 17:00:39

[MattyB]

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Edited By MattyB on 07/03/2018 17:00:23

[Adrian Smith 1]

Thanks Frank,

I am running it on 24x8 JXF prop with 12S setup using 2 x 5000 mAh 6S lipos, also as an alternative 6000 mAh 6S x 2, all at 40c thereabouts.

MattyB, thanks for that. I will study the listed link you provide.

[Simon Chaddock]

I note the motor spec refers to "cruising power" which is just about half peak (80A) and even that is limited to 8 minutes.

It seems the motor is more limited than the ESC.

[Frank Skilbeck]

Adrian, didn't have a JXF prop in the list so used a Dualsky 24 x 8, fresh off charge at WOT the motor will pull 112 amps, 4.8kw, 7,200 rpm, 15.7kg thrust, dropping off to 101 amps, 4.1kw, 6,900rpm 13.2kg.

Note these are calculations, but I've found Ecalc to be pretty good.

[Adrian Smith 1]

Makes for interesting reading, Frank. Seems to add up to me.

Simon, interesting what you say about the motor. The motor is the GA6000.8 V2 which is described as good for 3D flying ( I just do standard aeros so not something I would worry about.) Given if what you say is significant, I am sceptical of those claims and can't see how it would be suited to that style of flying.

 

Edited By Adrian Smith 1 on 07/03/2018 19:24:22

Edited By Adrian Smith 1 on 07/03/2018 19:24:59

[Frank Skilbeck]

Adrian, no problem, but I could have saved myself some work, Dualsky have it all there in a table. Note they quote the motor is good for 3D planes upto 10kg and at "cruising power" it's producing over 12kg of static thrust, so a 10kg airframe will actually be accelerating vertically at that power setting and would quickly get out of sight.

BTW Dualsky quote 101 amps on a 12s at WOT so it looks like that agrees quite well with Ecalc

[Adrian Smith 1]

Frank, the airframe I am using has an AUW of 8kg so no issues to be anticipated. You are right Ecalc seems a really good tool to use.

[Frank Skilbeck]

I don't think you'll be short of power!