General Suggestions needed!

Hy, i have in my stock a brand new 700 w. 35-42 1000 kv motor, i would like to put it in a plane that would be for sport and mild 3D flying, any suggestions for what plane should be used? i'm so confuse with all those numbers like kv torque/weight and so long, thanks for helping.
Than what esc and lipo would be needed.
 
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D.O.G.

Goblin 380 Supporter
:welcome1: Danial. This is my :2c: but I think you can use a heli motor on a plane and vice-versa. This is a job for Randy and other air-plane enthusiasts on this site :).
 

RandyDSok

Well-Known Member
what i need to know is what size and weight plane i should look for with that motor i have!

You are wrong saying that is all you need to know... what voltages does the motor support, how many constant and max amps does the motor pull with a certain size prop. What size prop... the kv tells you how fast it will rotate and it will limit how large the size of the prop is ( length and pitch of the prop ) ... It also limits how small of a prop you can use. The 35-42 tells you sort of the size of the motor but it isn't standardized, that can indicate the outside diameter of the can or the outside diameter of the stator. Either size will determine what size fuselage it will fit into.

Generally speaking... you are selecting for some around a sport plane if it was up to 7 lbs ( probably at most ) if using a 3s lipo @744w and spinning a 14x7 to 15-6 prop... since wingspan doesn't come into it except as a possible weight limit... probably something around a 48" - 51" wingspan would get you in the ball park.

Still, as I said at first, there is a lot more going into selecting parts for a plane... notice I didn't say select a plane for the parts... I don't do that. I select the airplane I'm interested in and then check what they suggest for parts. Going backwards as you are attempting to do... is a lot of work and you DO need to know what that stuff you mentioned is and means when making a selection.

If looking at flying any 3D at all ( light or heavy ) ... look at planed made for 3D. A properly designed 3D airplane flies perfectly fine for a sport flyer. The only difference is the amount of movement and size of the controls. For 3D flying you want a lot of both ( movement and size ) and if flying sport you'd just run the controls on a lower rate on your radio so they don't move as far.
 
Thanks, i know i try to play it on the wrong side, since i already own the motor. You talked about a 3 s lipo but what if i go with 4 s lipo?
 

RandyDSok

Well-Known Member
Thanks, i know i try to play it on the wrong side, since i already own the motor. You talked about a 3 s lipo but what if i go with 4 s lipo?

First, please note I wasn't recommending a 3s battery... I was giving an example of something I suspected the motor supported but doing that, without knowing the details you didn't provide... like make/model. The size doesn't matter as much as I mentioned because it isn't really standardized so we don't know much from that. The kv you listed, I've seen on small, medium and a few larger motors, so again not of much use here. The wattage... again I've seen listed on smaller, medium and larger sized motors so doesn't give actual specs that tell us what the motor does support.

You'll need to look up the specific specs of that specific make/model of motor and see what it does support for voltages. If it's a good brand, it may even list recommended prop sizes for specific voltages, but if this is originally made for a heli ( or you took it out of one )... they may not list that info.

Increasing the voltage would increase the speed ( kv ) the motor turns which in turn means you'd end up needing a smaller diameter/pitch prop than what you'd use on the 3s. This would also likely increase the amps/watts ... So you need exact specs for the motor you have to know what it may or may not support.

What info you need to know are the allowed working voltages, the maximum burst current ( amps ) and if you are lucky and they are a respectable brand, they should also list the recommended constant current, many brands don't list this and just mention the burst current which makes it sound better than it actually is ( aka marketing ). A lot of companies, if marketing at airplane users... may even list recommended prop sizes for the specific voltages they support. The wattage is nice to have but can be easily calculated if you have the working voltages and current.

So the first thing you must do is get the exact specs for the make/model of the motor. That will let you then select the voltages of the battery you need ( ie 3s, 4s as well as the capacity in mah )... and what ESC can support the above.
 
First, please note I wasn't recommending a 3s battery... I was giving an example of something I suspected the motor supported but doing that, without knowing the details you didn't provide... like make/model. The size doesn't matter as much as I mentioned because it isn't really standardized so we don't know much from that. The kv you listed, I've seen on small, medium and a few larger motors, so again not of much use here. The wattage... again I've seen listed on smaller, medium and larger sized motors so doesn't give actual specs that tell us what the motor does support.

You'll need to look up the specific specs of that specific make/model of motor and see what it does support for voltages. If it's a good brand, it may even list recommended prop sizes for specific voltages, but if this is originally made for a heli ( or you took it out of one )... they may not list that info.

Increasing the voltage would increase the speed ( kv ) the motor turns which in turn means you'd end up needing a smaller diameter/pitch prop than what you'd use on the 3s. This would also likely increase the amps/watts ... So you need exact specs for the motor you have to know what it may or may not support.

What info you need to know are the allowed working voltages, the maximum burst current ( amps ) and if you are lucky and they are a respectable brand, they should also list the recommended constant current, many brands don't list this and just mention the burst current which makes it sound better than it actually is ( aka marketing ). A lot of companies, if marketing at airplane users... may even list recommended prop sizes for the specific voltages they support. The wattage is nice to have but can be easily calculated if you have the working voltages and current.

So the first thing you must do is get the exact specs for the make/model of the motor. That will let you then select the voltages of the battery you need ( ie 3s, 4s as well as the capacity in mah )... and what ESC can support the above.
those are the infos i have:
KV: 1000 KV
Max current: 47A
ESC: 50~60A
Cell count: 3s~4s Lipoly
Pole Count: 14
Bolt holes: 25mm
Bolt thread: M3
Shaft: 5mm and 11 x 7 prop was suggested.
 

RandyDSok

Well-Known Member
Then I'd be cautious and expect constant amperage in the 37-40a range ... and max current is the 47a burst which means for just a few seconds.

I'm guessing the 11 x 7 prop is if you are using 3s battery ... on average you will likely be able to drop an inch in diameter or down in pitch for a 4s but still static testing on the ground with an amp meter plugged in inline is recommended so you do not exceed the max and constant amperage rating.

As for picking an airplane for you... that isn't going to happen. You should have an idea of what size range of airplane to look at... so the rest is looking at ones in that range and compare what they recommend for them and see if it's close to what your motor provides. It's a lot of looking at a bunch of airplanes at this point to find some to pick from that also fit what you like the look of and also fits what you want the airplane to fly like. As I mentioned, this is a lot of work to find something in this direction.
 
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