HL X Flight times

[JLO]

Guys I wanted to cross reference the flight times some of you guys are getting with your setups

a respected member from another forum mention that with the same motors but with Microkopter BL3 and MK FC he was getting way more time in the air

Im currently flying a CS8 coax frame with T- Motor U5 motors, DJI A2 controller, T-motor 40A Pro Esc, Power Hungry dist board,
TM 16x CF props, 2x 10K 6S lipos, Gimbal M5 and a AUW of about 23.5 lbs, I'm getting about 8.5minute flight time with 20% left does this flight times make sense to you guys


any sugestions

 

[DIPswitch]

Is that other platform a "Flat" config ?
I have heard that coax config its not as efficient as a flat.

 

[SleepyC]

That’s about right. as you have to be around 70%+ at hover.
The U5 at 50% with a 16” prop have 1180G of thrust each.. so at 50% throttle you have around 19lbs of thrust at 65% with the coax “loss of efficiency” you are probably around 65 - 70% hover pulling probably around 100 amps.

That being said, I think the 40amp esc’s may be a bit light, I had some U5’s on 40 amp tmotor esc's on an X8 and they got pretty hot flying a rig that weighed just 20lbs...

But I would estimate around a 12 min flight at 24lbs, so 8-9 min with 20% left makes sense to me.

 

[JLO]

Hi it is a Coax setup, I'm flying in warm Florida at sea level
SleepyC, when I was building this setup I had the motors first with Maytech 65A Opto ESC, I was having commutation problems, so I change to the T-Motor 40A pro ESC suggested directly by Tiger and problem solved, I did a small modification to the outside of the Esc I cut out the shrink plastic exposing the heat plate and silver glue a heat sink to each Esc, I check them regularly they are always light warm the motors are also just warm never hot, the bottom motors are a bit warmer

 

[saidquad]

I have almost the same setup. X8 , U5 , 40 Amp T-ESC, 15" props, WKM, 2x 11 amps lipos. AUW 7128g (15.43 lbs). I have not maiden yet but I hope for at least 20 mins flight time. I have configured custom motor mix so that upper motors run 10% slower than lower motors. I heard somewhere that it will minimize the efficiency loss of X8 t0 bellow 10% (I hope so).

 

[JLO]

Hi saidquad you are pretty light at 15.43 Lbs are you calculating your AUW of just the copter no gimbal yet?
one theory that I am going to explore is that motors have a sweet load max, after you cross it eficency decreases rapidly (its a theory)
by the way I would like to custom adjust my motors mix too but have not find much info on the subject for DJI controllers do you have any links on this subject
thanks

 

[SleepyC]

Most of the “sweet spots” I found are around 55%throttle for hover. More than that and time suffers.

Instead of running motor mixes, I run 15.5” props on top and 16.5” on the bottom. Keeps everything pretty close to the same efficiency.

I have noticed much improved flight times and temperatures after switching to the Avroto 2015’s and changing to a much larger PDB, the 300 AMP Hungry clone.

 

[saidquad]

Hi saidquad you are pretty light at 15.43 Lbs are you calculating your AUW of just the copter no gimbal yet?
one theory that I am going to explore is that motors have a sweet load max, after you cross it eficency decreases rapidly (its a theory)
by the way I would like to custom adjust my motors mix too but have not find much info on the subject for DJI controllers do you have any links on this subject
thanks

No gimbal. I'm planning to use this setup for mapping without gimbal. 15.43 lbs includes the copter, a sony NEX7 (no gimbal) and a gopro including h3-2d mount and 2x 11 amps batteries.
About custom mixing this may help
http://www.rcgroups.com/forums/showthread.php?t=2133373&page=17

 

[JLO]

Thanks saidquad interesting I'm going to give it a try il post the results
if any one has more info on the DJI mixer modification for a Coax setup greatly apreciated

 

[saidquad]

Looking forward to your feed back. I have time to fly only on fridays and last friday it was raining. May be this friday I can test it.

 

[JLO]

The A2 mixer has 0 in all the boxes vs the Wookong that has 100% in the boxes in the Wookong if you want to decrease the throttle my understanding is that you replace the 100% digits with like 95% but in the A2 the 0 mean what? if I want to decrease the throttle 5% what number should i put in the A2 mixer?
I appreciate your help

 

[saidquad]

I don't have A2 but I guess you should set it up as WKM, meaning you insert 100% for lower motors and 95% for upper ones. You can take off all props and test it with 0 values for all motors and see if motors rotate, then test above values.

 

[saidquad]

I did maiden today. 20 minutes (mostly hover). Batteries were 3.6v pr/cell offload (maybe drained too much?!!). Pretty much stable in wind.

 

[JLO]

Thanks saidquad i will try with the A2 this week