Servers by jDrones

Big Vtol Need Advice on Propeller and Power System

(Tony Atma) #1

Hello guys, I plan to build a big Vtol quadplane with MTOW about 60 kg. I have built several small Vtol without any problem before. I use eCalc for power system calculation which I believe is good enough. The main problem that I found is about to choose the best (most efficient power system). First I can not find the proper propeller size in the market, that match with my eCalc calculation. I will use either Pixhawk2.1 or Cuav Pixhack 5 (which one is better??) running ardupilot. I need advice especially about the propeller and motors for this system. Apc does not have big prop. I consider to use big Eolo SS or MAD motor. Any advice or recommendation is highly appreciated . Thank you very much. My best regards.

(rollys) #2

Maybe consider T-Motor?

Good luck.

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(Tony Atma) #3

Yes Rollys, T-Motor is one good choice besides Eolo SS and MAD motors. But big propellers (about 36") with high pitch is not easy to find. Any advice between Pixhawk 2.1 and Cuav Pixhack 5 ? Which one has less problems ??
Thank you .

(rollys) #4
  • You may have to contact them regarding large size props.
  • Sorry, I have no experience with neither Pixhawk. I mainly use the Pixhawk 2.4.6 and 2.4.8 and do have a Pixhawk 4 but haven’t worked with it yet.

Good luck.

(James Pattison) #5

KDE have some impressive larger motors and props. They’re expensive compared to some, but for a large machine you need to consider whether skimping is worth the risk.
Similarly, for that size vehicle I’d suggest testing a range of flight controllers to measure the sensor performance in your vibration environment. The Hex, CUAV, Holybro and mRo fc’s are all pretty good but have different sensor combinations and different vibration management solutions: you might find one suits your vehicle better than others.
A 70kg machine is awesome, but dangerous. A proper design and test regime is necessary to achieve a safe outcome.

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(Tony Atma) #6

Hi James, any suggestion about motor and props. that are suitable for 60 kg quad motors (model and size) ? Thank you.

(Roger Ronald) #7

The KDE site ( for the motors recommends a prop or two for each motor and has a good amount of data showing thrust amounts vs. current draw. You can find the data you need there.

(Tony Atma) #8

Yes I knew KDE, but now the problem for my Vtol plane is, when I use folding props for the quad parts, the props. may stuck during flying with the plane mode. If the props. Stuck in the air, how can the folded props spin again when the plane change mode to Multicopter? Any advice how to avoid this problem?

(Roger Ronald) #9

While the KDE folks seem to favor folding props, there’s no requirement for you to do so. Their thrust/power data ought to be relevant to similar sized fixed props. E.g., I generally use KDE motors and APC props but I get much of my sizing from the KDE data.


(Tony Atma) #10

Are you saying that it is better not to use folding props.? I think so.

(Roger Ronald) #11

I don’t know enough to provide a blanket assessment. However, I certainly wouldn’t use them on a VTOL unless I had a good reason. Even then, I’d probably start with fixed props to establish a good baseline before injecting something different.