Hello all, I've been trying to get a better understanding about weight and flight time with my copter. I'm quite new to this game and jumped on a movie production right after I got all my new gear.. I've obviously already done some testing with my brushless gimbal and a Canon 5D and it went very smooth but Picture wise,, the 5D won't do the job so I need to get the blackmagic 4K up in the air! I got a cinestar 8, 500mm booms with 15.5 carbon props, u5 Engines and BL-ctrl 3.0. According to the: My ideal payload at 12 kg (26lbs) leaves me at 65% throttle; this will include 2 x 10.000 mAh lipos with the rest of my gear. Now if 65% throthle is too much I'm concidering to drop one battery to loose 1,4 kg (3,1 lbs) ?? And what would my flight time be? I'm very ancious to test this out myself, would be awesome to get some experienced input on this before I make any hasty decisions! Also to Dave King: Thank you for your inputs on getting me in the right directions for building my cinestar! It was very helpful! cheers, Adam
I would consider dropping to 8000 or 6000 batteries. Depending on how your copter is built, switching from dual to single batteries could present some balancing challenges. Plus, you have to consider your vertical balance, which will change dramatically if you drop 1kg or more off the top of the copter.
As soon as I get back from this shoot I'm ordering 550 booms and 16 props, might even consider the 600 dooms with U7 engines and 17 props.. I just have to make this work with what I got while I'm here.
I could imagine it to be an issue if the copter is too top-heavy but does it matter as much If I drop a kg from the top?
Adam I noticed that when I went from a 10 pound payload to a 12.5 pound payload my hover throttle went up to 70% as I think that 25.5 pounds GAW is really the limit for these motors. I"m waiting to see what KDE's new motors are like, I might try them or the U7 420's with 16 or 17 inch props.
I went from 68% to 62% hover throttle when I switched from 15 inch props to 16 inch props. Make sure you use the Tiger 16X5.4's.
Moving the batteries closer to the center hub won't affect hover throttle. It will improve how responsive it is and overall flight performance IMO.
If you decide to try the U7's you must make sure the motor/prop combo does not excceed 40 amps at full throttle. The lower the number the better off. The U7 420's with 17 inch props are very close at 39.5 amps and with the results I seen from another board member with their 4014's I'm going to hold off until more testing and evaluation is done.
Switching from 10,000 to 8,000 batteries could do the trick with getting the hover throttle down to where its needed but it sure will kill flight time if you leave the same reserve power.
So with the 500mm booms the 15,5 props are the biggest I can go right? So was your 25.5 pound limit with the 15 or 16 props?
What is your input on using one 10.000mah lipo instead of two to decrease weight? I really havent pushed the limits yet with my copter and very long flight time is not as important in this case since were doing controlled takes for a movie shoot and 5-8 minutes flight time at the time would do the job, I'm simply stuck at figuring out how to calculate flight time thanks
Yes with 500 mm booms 15 inch props are the largest. I purchased 550 mm booms and cut them down to 520mm and run 16 inch props. With 15 inch props at 25 pounds my hover throttle was close to 70%.
I am not a fan of the one battery concept as I have always flown with 2 batteries since day 1 on every combination build I have had. However sometimes you got to do what you got to do and we are in the very infinite stages of getting motors that are designed to reliably fly 26-30 pounds. It might be a good short term bandaid.
valid point didn't think of that, even with the U7 and 16.5,4 props, the hoover weight at 65% throttle should be around 37 pounds (if the chart is correct) which is way better than U5's 25,5. Would be interesting to find out more about this!
14.5 to 16.5 minutes with flat 8 and U5's with 2 QC 10,000 batteries 12.5 minutes with X8 and 4014's with 2 QC 10,000 batteries