My personal experience now that I've been flying the coax for some months is it's better in every way. No issues for me landing due to vortex.
I would STRONGLY advise you to set the esc's to NIMH mode and cut off at the lowest voltage possible I believe it is 4v TOTAL. Not per cell. Essentially this means it will never cut off, because you wouldn't be able to fly with a 4V pack. I had an issue once where 1 or 2 esc's cut off due to low voltage (had them set at 2.8V/cell which I thought they could never possibly reach) because one of my two packs dropped a cell. If this happens, then there might still be enough juice to get you down safely, but the voltage calculation might cause a cutoff, and since all the esc's won't necessarily cutoff at once, you have a flip.
My experience with them has been the opposite as far as descents go. Much smoother if not almost perfect fast descents which are not possible with the flat.
Hi Tim Thanks very much for the advice, i will do that. I had set other escs on an another hex to NIMH, not sure how i forgot to do it on this build. I really appreciate the help. cheers
Reading all of these reviews has me thinking. Im currently running 14x5 Xoars on my Flat CS8. There is no one with 16x5's or 15x5's in stock at the moment that I have seen. Would I benefit switching it how it is to an X8 without getting the bigger props? I don't mind losing some flight time. Im currently getting 10.5 minutes with the Fs700 and landing with 30% still in my batteries. Just want to make sure switching to the X8 without getting bigger props isnt going to lose any lifting capability. If it is, Ill just have to wait to try it when props come in stock.
You will loose efficiency. This is either in lifting capacity, or flight time. You choose what you sacrifice. I have converted my flat CS8 with stock MK electronics to X8 and my flight time was %20 less with the same weight. (Tiger MT2814 motors with 14" props). I reverted it back to flat CS8.
If primarily you are looking to maintain your flight time, the X is not for you. You do need to run larger props to get within 10% of your original times and you get a little more with more pitch on the bottom props. Probably the best you can hope for is 7-10% loss. Tristan, I would suspect you'll get around 8-9 mins with 16X5's... or something like that. I run the same setup as you on one of mine. What is your AUW with camera and trimmings?
AUW with camera and trimmings is about 10kg when running the Fs700, tad more with the Epic. My main concern is not flight time, I am fine with 7-8 minutes and more batteries. My hover throttle is higher than I want it to be but I really dont want to make it any bigger than it is for transport reasons. (I have my pilots license and a turbo 182 and its already a pain getting it in the plane) So ideally if i could do the X configuration with bigger props and get my hover point closer to 50% that would be ideal.
Ya I run my Epic/Scarlet with a Bolt downlink, Bartech focus and cine primes as a maximum payload with same everything you have at 12 kg at about 60% hover. A slightly lighter setup without the focus and cine primes at 10.5 kg makes my hover around 50%. This is with 16x5's and have been messing with 16x7's on the bottom recently. I think a lighter setup like your fs700 at 10 kg would probably fly fine with 15x5's but 16's are the way I am sure. Also make sure your lipo plugs are EC5's... you'll get hot connections in hot weather with the X if you have mismatched wired gauge or connections. I don't notice it as much at 10 kg but at 12kg I had to switch all of my Deans out.
Thanks for the info Brad. Yea, I have always used EC5 since day one and always have on my 3d helis as well. I guess I will just wait for props to come in stock and give it a try!
haha. I have a quick job tomorrow and then nothing with it until next week. Ill swap it over tomorrow night and give it a test. Suggestions on a custom mix or just use the standard dji one?
use the one I posted earlier in the thread... http://forum.freeflysystems.com/index.php?threads/coaxial-cinestar.782/page-6#post-13074 the standard tends to yaw around.
Got my one cinestar converted to an x8. Waiting on props so I just test flew it with 14's but it seems very stable. Ill post some build details and pics on my 550mm flat octo and my 450mm x8 tonight.
Prop question... I'm using 14x6 Xoar props top/bottom on my X8 950mm. It flies amazingly well with an Epic and Zeiss CP2 lens. I have heard some people putting either: A) 1-2 inch larger props on bottom with same pitch as top B) same prop size on bottom but higher pitch Also how are people liking / disliking wood vs carbon for a heavy lift? I'd like to hear some of your experiences to save me a few hundred $$$'s in prop testing
^^^^ I'd also like to know how many people are using different size and/or pitch props for top and bottom.
Can I ask Brad, what motors and escs are you using on your DJI cinestar X8? Nice DD gimbal by the way