700 E class better on 3500mah 12S?

[darkfa8]

it's hard to read your graph....

1. what head speed were you set for?
2. what was your average and peak Power Out?
3. What is the weight of your model WITHOUT the flight pack batteries?
4. How much current did you put back into the batteries after this flight?

[weedwacker]

Yeah that graph pic is fuzzy ill see if i can make it better in a bit.

1. headspeed set for 2050
2. avg. power out- 45.8, peak 100
3. need a scale, wifey thought hers was broken
4. i returned approx. 2700 to each 6s

[darkfa8]

what gearing are you running?

a suggestion: if you can get the average Power Out closer to 100, and have the Power Out bouncing off of the 100 mark throughout the flight, the ESC will be running more efficiently, less heat too because the MOSFETs will be staying on longer... they are more efficient when they are in one state for a longer period of time..switching one & off more (lower Power Out) causes more heat.

You also pulled a bit more than 80% out of the batteries. You should probably dial back your timer by 30-seconds, or up to a minute once you start throwing the model around a bit harder. Either way, impressive.

[weedwacker]

(tried to make the graph better)
Im using the 12t on the mx motor.
To get my power closer to 100 do I just increase the headspeed?

I tossed it around a little more today and it was very windy and I nearly lost the batteries, same flight time just more work.

[darkfa8]

ok, looking at your graph it looks like your Power Out and efficiency are actually pretty decent. The average was so low to you sitting on the ground so long.

You should open up your data file and crop it down to just the section where the model was actually airborne and see where the Power Out, RPM and other numers fall and make any tweaks based on that info.

On that gearing, to increase the Power Out and get it closer to bouncing off 100, almost like a rev limiter, you would need to go up in head speed, OR if you want to maintain the head speed you're at now, you would have to go down in pinion size

Read up on Bert's info to get a better feel for what to look for in your graphs and how to get there:

http://www.bertrc.com/archives/675

[weedwacker]

Good stuff thanks for the tips. Ill play with the graph some more and tweak the esc accordingly. Apparently my curves are wrong for gov mode too. Always learning in this hobby.

[darkfa8]

if you're using SetRPM governor mode then your normal, idle1, idle2 should be (assuming Auto-Rotation is enabled)

Normal 0% flat line
Idle 1 30% flat line
Idle 2 75% flat line
Idle 3 (if used) 100% flat line

more info if you're not aware - See Instruction Documents at bottom of page for heli-specific setup info NOT packaged with the ESC:

http://www.castlecreations.com/support/documents.html

I'll post my revised results from my model after I finish some changes to it

Where on the island are you from?

[weedwacker]

I was at 0 70 and 100 but didn't setup auto- rotate yet because I didn't want to miss my flying time.
I'm on the upper east side of the island.

[QYT001]

I like TP 45C batteries. What batteries are better in terms of CG on TRex 700E 3800, 4400, 5000 mAh?

[darkfa8]

that's really hard to answer because of all of the variables involved:

1. main blade weight
2. electronics weight
3. airframe weight

[QYT001]

If you'll read what Align recommends for new F3C heli, it's 4500-5200 mAh batteries, probably to maintain the proper CG I guess. If the batteries are below 4500 mAh, the tail becomes heavier, then nose of heli.

[darkfa8]

regardless of current capacity, battery weights of the same capacity can vary due to C-rating and other manufacturing techniques.

what you can try is once your model is built and loaded with all of your electronics, sans battery, add some weight (clay, play-doh, etc.) until the model balances. Then, once that weight is determined, go find a pair of batteries that come close to that target weight.

[oldschool269]

well i have finished my 700e , the new mx motor ..etc.... well i had to fly it
so i used the same 2600ma 40c constant packs i have been using on the 500 , yes it was tail heavy , so i slid the packs right forward ... its cool , did 30 flights like that ....
anyhow i ordered myself some 4000ma 6s packs , they are on their way ... but on the weekend my friend lent me some 5000ma pack to have a fly ....

in short i hate it . with the 5000s on board it flys like a truck , the flippy , fast moving heli i had with the 2600ma packs , was gone , instead it flys heavy , falls out of tic toks etc , loads up everything .

i couldnt believe how much heavy packs killed the fun with this thing .... i am not looking forward to the 4000's getting here, i may sell them as new , and get some more 3000's

the hang time i get with the light packs , the cold motor, and less stress on everything have to me far outweighed the small increase of power carrying the big bricks around.and using heavy collective all the time

to anyone who has a 700e , and a 500 , flys 3d , try the light packs ..

im not saying it will suit everyone , but the less weight on board makes the thing just so much more agile
and the hang time inside the maneuvers is awesome
it floats around like an angry shock flier

im flying 4 mins with 80% capacity good collective control 3d
to describe flying it , with the light packs it just floats around , ready to change direction without a whimper, everything runs cool , motor esc and packs all really cold compared to the scorpion motors i have used in the past , i didnt notice a difference in power flying the mx to a hk 4035 scorp ??? just the mx , runs cold ?

with the heavy packs , it was just fighting the fall, offsetting the weight with collective .. constantly throughout the flight ., . sure bigger air can be had , but the motor came down smoking hot, and it just wouldn't change direction as cleanly ..

my 700e i built to be an acrobat . to me , its awesome with some smaller packs , that charge super fast
i can fly all day on 4 flight packs as one set is discharged the others are ready to go ... they only take 15 mins to charge with 2c charging , if the motor is cold , you can fly back to back packs thru it
jason

[EatMorePizza]

Originally Posted by weedwacker

Im not a very skilled pilot yet but I ran a mild flight around 5 min on Voltz 3300mah. Heres a video and a graph to help see.

is that randalls island?

[EatMorePizza]

wow im getting really jealous of these flight times with a lighter pack. My heli is extremely agile with my current setup, but i could only imagine how it would be with 4000 packs. On my 500 i ditched the 3300 packs and went with the 3000 packs. The difference was unbelievable. Exactly like oldschool reported. I dont know 3500 packs are even feasible with the neu kde motor. maybe 4000 packs, but my flight times would go from 4.4 to 3.4

[darkfa8]

Jason,

What size blades, collective and cyclic pitch range are you running?

The 5000 packs essentially make the electric model on par with the nitro version weight-wise. Maybe a little less depending on components and if you're FBL.

They key to performance lies in your blade choice, pitch range, motor and gearing. This 700 is NOT a heavy model in comparison to other out-of-the-box 90-size electrics.

At some point, going to a lower capacity, albeit lighter battery will fail to return sufficient flight times especially as the packs age and are effected by temperature (colder ambient temperatures REDUCE rated pack capacity) and also reduce the buffer of available power.

BTW - with a FMA Direct Power Lab 8 charger and suitable 24vdc power supply, you could parallel charge 2 6s5000 packs at 5C in 13.5 minutes. Lipos with charge rates of 10C are already available (Kypom, others soon.). So, actually, you could fly all day long with one flight pack.

[oldschool269]

Originally Posted by EatMorePizza

I dont know 3500 packs are even feasible with the neu kde motor. maybe 4000 packs, but my flight times would go from 4.4 to 3.4

as you reduce weight the motor draws alot less amps, your not dragging and anchor around under the frame.
so you get a much longer flight time ...less wattage, less amps needed to gain the same power to weight ratio !!!!
the bonus is everything is less stressed . .. i dont need a spare maingear ..

i noticed when i was flying the 5000's on the weekend i didnt hit the collective as hard. !!!!!!!! , my mind just decided it wasnt worth it stripping a main gear on borrowed packs
.
my little packs only get hot if i fly it out for 5 1/2 or 6mins and drain the packs 100%
jason .

p.s.
for just hacking around upright , big circuits and loops etc , the 5000's are great .. and the right choice for that type of flying .

[oldschool269]

Originally Posted by darkfa8

Jason,

What size blades, collective and cyclic pitch range are you running?

The 5000 packs essentially make the electric model on par with the nitro version weight-wise. Maybe a little less depending on components and if you're FBL.

They key to performance lies in your blade choice, pitch range, motor and gearing. This 700 is NOT a heavy model in comparison to other out-of-the-box 90-size electrics.

At some point, going to a lower capacity, albeit lighter battery will fail to return sufficient flight times especially as the packs age and are effected by temperature (colder ambient temperatures REDUCE rated pack capacity).

hi
align '3g' 690s (hot blades!!); 15 deg collective 11deg cyclic,mx 510,cc ice 120hv w 100% flat thrott with 12t , sk720fbl ++ awesome combo 2600ma , turnigy blues 40c const 50c burst .... the 3000ma , 40c constant packs would be even better
( with the 2600s you can feel the power fall off after 3:30 .. so the suggestion of 3000/3300 has merit )

if you fly 5000s and get say 6 mins of 3d , land .... how long does the setup take to cool down ?
with little packs , i land change battery's and go straight back up ...


umm , i set the swash bellcranks to flybar (outside holes) and like the extra punch the cyclic has
p.s. its tail heavy , i fly backwards alot !


it does bog with 710 sb's or 710 red devils or radix 690 sb's on it , if your not carefull .!! lol to much chord
i am just reporting what i have been trying ...
i was trying to get the 700e to fly half as good as my stretched 600 esp !! whew!!
lol the stretched 600esp is better at everything ! lmao

power to weight , power to weight , that is the question.............
jason

[darkfa8]

Jason,

The heavier packs require larger blades to compensate for increased weight, you'd also need to reduce your pitch range since the larger blades would provide more lift per degree of pitch, you would likely have to regear the motor to compensate and allow the ESC to run at it's most efficient.

If you just popped in a 12s5000 pack into the model with the specs you just listed, yeah, no wonder it was a dog. You're trying to pull another 1+lbs of battery around on an insane amount of pitch on too small a blade and the motor isn't geared to cope.

It bogs with 710s on it because you're trying to pull more pitch than your power system can adaquately support AND/OR further collective management needs to be employed.

[oldschool269]

Originally Posted by darkfa8

Jason,

The heavier packs require larger blades to compensate for increased weight, you'd also need to reduce your pitch range since the larger blades would provide more lift per degree of pitch, you would likely have to regear the motor to compensate and allow the ESC to run at it's most efficient.

If you just popped in a 12s5000 pack into the model with the specs you just listed, yeah, no wonder it was a dog. You're trying to pull another 1+lbs of battery around on an insane amount of pitch on too small a blade and the motor isn't geared to cope.

It bogs with 710s on it because you're trying to pull more pitch than your power system can adaquately support AND/OR further collective management needs to be employed.

completely agree. !! hmmm ill try 710s on the 4000's when i get them ..
then ill look at shaving every gram of it

how much weight and power will the frame take im not sure ,,, heheheh
i fly every day , and im still on my original maingear ...
i dont want to have to fly soft because it pops a main gear everytime you do a rainbow.