Hello all, I am stuggling to find an efficient motor/prop to use with a quadcopter I am going to build. I have seen on many forums people say that they can achieve over 1kg of thrust per 100W of power. I have taken all motors I could find on HobbyKing that have test data and have arranged it all in an excel document that calculates its thrust per 100W. The highest I could find is .675kg/100W. If anyone could help me that would be great. I am new to this, studying aerospace engineering at the moment so this is turning into a big personal project for me. I will include a screenshot of the top of my list in terms of thrust per 100w. If you have any other advice for me that would also be greatly appreciated. Thank you!!
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Thanks! The main reason I wanted to go with an X-8 config instead of the traditional octo, is because of the minimum motor to motor spacing. I just calculated that with a traditional 8 motor layout and 18 inch blades, I need a minimum spacing of about 1200mm. That seems like too much to me but if it is okay I could do it. Also, the reason I chose the 10A esc is because Ecalc was telling me that at my maximum thrust I was only pulling about 6.3 Amps. Could you tell me why then it needs 40 Amp? The power system is probably the part that confuses me the most. I fount that maxamps has a 11000mah hour battery that has the same weight as the zippy 8000mah. But i guess that is meant for smaller copters. I like your idea about the arrows! ill try it out
Hey Ben. When choosing an ESC it's best to look at the motor mfg. specifications for the maximum current that a particular motor can draw, and then add 10 AMPS. That way you're certain your ESCs will never be overtaxed and that in a worst case scenario they will be able to deliver the power your motor may demand. I believe your motors are capable of drawing up to 30A which would suggest a 40A ESC.
For added protection I also placed foam water pipe insulation on my landing skids. It's dirt cheap, weighs nothing, and offers great protection while test. Any hardware store should carry lengths of it.
C
Hello again, thank you for your advice. Putting the 18x5.5 props into ecalc I get 28 minutes of hover but only 7 minutes of combined.. also the throttle at hover is at just 27%. Is this a little low? with 16x5.5 I get 25 minutes of hover and 9 minutes of mixed, where hover is at 38% throttle. With me possibly planning on putting a camera with gimbal in the future, making it probably weight somewhere in the 4.5kg range, the 18" props give me 15 minutes hover and 6.5 minutes mixed. Do you think it would be a better idea to go with smaller props like 15" or 16" now, and when i get a camera and gimbal I could purchase 18" props as well, and just switch them? I am planning on having the motor mount non-permanently so I could adjust the spacing as needed.
Also, even with a future flying weight of ~4500g, with 18" props the most current that ecalc says it will pull is 12.22 amps. In this case do you think it would be okay to go with 30A esc? maybe even a 20A? I am trying to save on weight as much as possible.
Once again, thank you
Assuming 4500g is the full-up weight with the camera and gimbal, I would start with whatever props eCalc recommends would give you a hover at between 40% and 50% throttle.
As for the ESCs, if you're confident you will never exceed 15 AMPs on a motor then 20A ESCs should be fine.
Okay, I believe I have everything figured out. Here is my parts list. The only thing I am worried about is that the total cost is coming to $1300. I can do that... Its just a lot of money to make the decision to buy everything quickly.. UGH
parts list.xlsx
I know what you mean, but considering it's an X-8 with FPV you're actually getting off pretty darned easy.
; )
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