motor size question

I've been building at around 28-30 wingspan, and so far the A-size motor (1806-2280) works perfectly. My Trainer Stick on 3S will go faster than I'm comfortable with so far! This size aircraft works well for me, and I'm not particularly after speed.

I'll be wanting to build a twin. I'm finding this EMAX RS1606 3300kv available. Would two of those suit my needs? It says 3-4" props. I could live with 4" 3-blade props. Is there a different motor that would best for me? It seems a waste to carry the weight of TWO 1806s if I don't need them.

Thanks a bunch!
 

Wildthing

Legendary member
Most motors have a spec sheet of what they produce for power , watts and thrust using different props and what voltage. If you know roughly what the plane will weigh all out with battery as long as you have a 1 to 1 ratio, weight versus thrust it should fly with ease.
 
Yeah that's right, the H pack.

I just found this: Xnova 1406 3100Kv Motor
I imagine we're in the ballpark. Who has more info to share?
Most motors have a spec sheet of what they produce for power , watts and thrust using different props and what voltage. If you know roughly what the plane will weigh all out with battery as long as you have a 1 to 1 ratio, weight versus thrust it should fly with ease.
Perfect. I knew that ratio thing would show up. Thx.
So seriously, the numbers don't lie right? And for my application I suppose I'd want a lower kv option, when there is an option. That Xnova has three kv ratings from 3100 to 4000, so I'm thinking in that case I'd want the lowest.
Any of this sound wrong?
 

Wildthing

Legendary member
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Here is all their specs, Now depending what batteries you have, (size and volts) plus what do you have for esc's or if you are ordering all new it doesn't matter then. What will the plane roughly weigh with what power set-up plus how big is the battery hatch which can limit what battery you are able to use you should be able to come up with your setup.

As an example the 3100 kv using the GF (gemfan) 5030 prop on 3S is producing 491g (17.3 oz) on 3S and amp draw is 13.2 . Two of them should be able to carry a 34 oz plane no problem and you should only require 15A esc's . Now the specs are not always correct I find, sometimes the thrust is exaggerated a tad so allow for that .
 
View attachment 177858
Here is all their specs, Now depending what batteries you have, (size and volts) plus what do you have for esc's or if you are ordering all new it doesn't matter then. What will the plane roughly weigh with what power set-up plus how big is the battery hatch which can limit what battery you are able to use you should be able to come up with your setup.

As an example the 3100 kv using the GF (gemfan) 5030 prop on 3S is producing 491g (17.3 oz) on 3S and amp draw is 13.2 . Two of them should be able to carry a 34 oz plane no problem and you should only require 15A esc's . Now the specs are not always correct I find, sometimes the thrust is exaggerated a tad so allow for that .
Well that's over & above the call of duty. Thanks @Wildthing !