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Picking your power system. Questions inside.

MrGravey

Senior Member
#1
I want to build and fly more stuff. The problem right now is I have limited knowledge and unlimited desire. I'm reading and learing a lot so as to limit the limits placed on me by my limited knowledge right now. I am however missing something I feel needs to be next. How do I pick my motor, ESC, prop and battery set up?

I think the best way to make all this work in my head it just to walk me through you process. I don't understand how to take all the numbers out there and know if I can get the power I want, if the ESC will hold up, if the battery will give enough power, and what props will work best with the set up.

For example, if I wanted to build the FT3D I will need the more powerful pod design. Most, if not all, of the recommended parts are out of stock in the US. So, if I wanted to find something else that will work how would I figure that out? I understand this may be a very large question, but I'm willing to read if you just want to link me to good information to help me understand. I just have to nail this down to feel better about the hobby and my knowledge of it and reading the random bits I can find just isn't getting me where I want to be.

Thanks
 

zev

lumpy member
#2
well, the easiest thing to do is use someone else's tried and true power system (obviously) but if you cant do that, start with the motor. go to the motor specs, and find the "max current" or "max load" of it. now find an esc that has a good 10-15% higher rating then that number (for example, this motor has a 35a max current draw, so I would get at least a 40a ESC). now to choose the battery. find the "Cell count" or "required voltage" of the motor. if it has a cell count (it will like 3s-4s, or 7s-9s, or what ever) then just choose a lipo that has the same number of cells (so if it says "3s-4s" get both, (if you can spare the cash…) and find which is better for your plane). now, if it doesn't have that, but it has a "required voltage" spec, just remember that a 1 cel lipo is 3.7 volts, so if the required voltage 7.4 volts, you need a 2s, if it is 14.8 volts, you need a 4s. now for choosing the MaH of the battery (this is like the size of the fuel tank). I would say get the highest number you can get and still carry it on your plane with a little weight to spare.


about the prop, I am going to let someone else do that because it is the most complicated part, and as a noob myself I don't think I could give good advice.
 

Foam Addict

Squirrel member
#3
Are you a relatively new pilot? If so, build the FT flyer or the old fogey.
I have been flying for 2 years, about once a week, sometimes more, and still I cannot handle the FT3D very well. I can barely land it in one piece, and that was because I gave the remote back to the guy who built it.
Just curious, and the more Info the better.
 
#4
On the e-flite web site there is a chart that has most of the information you are looking for. At this time I can not find it for you but try going to the site and look there. Wish I had more for you.
 

zev

lumpy member
#5
also, I think you might get your questions better answered here if you ask more specific ones like, "how do I choose a ESC to go with my motor?" or "what prop for my motor?" instead of a very general one like you asked. I will help all I can, but I think you will get better answers from others if you do that. just because writing a ten page post answering a huge question is a little daunting to all is flitetesters :p
 

MrGravey

Senior Member
#6
Are you a relatively new pilot? If so, build the FT flyer or the old fogey.
I have been flying for 2 years, about once a week, sometimes more, and still I cannot handle the FT3D very well. I can barely land it in one piece, and that was because I gave the remote back to the guy who built it.
Just curious, and the more Info the better.
That is a yes and no answer at the same time. I haven't been flying real models for very long. I have however been flying a ton and have more time than I care to think about on simulation with real TX. The FT3D isn't super high on the list of things to do right now, but it is on my mind and I wanted good information before I did anything else. I have a few of the friendlier planes FT has put out already. I LOVE the FT Delta.

Does the discharge rate on a battery have an effect on the ESC? I think that discharge rate is really only used to the fullest if the motor can pull that much power. Therefor is the motor and ESC match up well the discharge rate on the battery only matters if it is less than what the motor can draw. I think that, but I ask anyway because I have been wrong before, and it is sure to happen again.