700 E class better on 3500mah 12S?

[marcosp]

Hi everyone. Last week some guys at the club made a test on a 700E putting 500 lipos, 2650mah in series of course. They were concerned with the weight of the heli with 5000mah lipos, being it is more than 1kg heavier than an empty nitro, and almost half a Kg than a full tank one. They noticed the landing gear brakes easily even on rough autos, and when you crash, well, you are stopping a lot of mass there and suffers wuite more damage than a nitro. They argued the heli feels powerfull because of the torque of the electric motor and the higher headspeed, but that some maneuvers show the added weight were the heli feels heavy or stops like it's gonna break the air!!

The test was jaw dropping! The setup was not touched, same config, same headspeed. The heli was so light and easy to fly, punches were fast, reaction great, it hang effortlessly at the end of maneuvers, tic tocs could be done fast and furious without falling, a lot less collective was needed overall and listen to this, they flew 4 mins out of a 2650 mah putting back 80%............

We discused this a lot during the weekend, and checked amp logs to see if the lower weight implied less drawn amps which would explain why the flight time was so good. They estimate that a 3500 would give above 5 mins, with a weight loss of around 600gr, which is on par with a half tank full nitro. Of course on smaller lipos you are closer to their max constant C rating, but this is also compensated by cheaper prices to start with, so even if they last less cycles you are almost at the same cost. A lighter heli also means you can get away with lower pitch which might help flight time too.

Everyone is selling their 5000 lipos and getting 3300 40/45C to 4000 25C ones. I am buying their lipos and am quite skeptic. I have seen Pros fly 4500mah, but nothing below 4000 for sure.

Anyone with similar experience or ideas? Could the 700 E class be better suited to 3500 12S systems?

[phobix]

Any chance you can get a copy of the amp log graphs and post them? I am curious about these tests as I run a 12S 3G FBL 600ESP with a 4025-630kv motor and I am averaging about 17.1AMPS throughout the flight with peaks of 40amps

[growmaster4]

i am running the same power systems on my 700 and my 600,i havent logged my 700 and it will be down until the weekend but the 600 pulls like 15amps average and 82 on a spike with a huge amount of pitch,i fly 2650s and 3000s on the 6 and 4000 and 5000 on the 700,i will try the 3000s on the 700 when i get it back and see how it goes.i think the 700 is about 2.5 lbs heavier than the 600,i may try the 600 stretched and see what kind of amps it pulls

[phobix]

Just weighed my 600, it is exactly 8 lbs with 2 x 2450 30C packs. I am very curious about these findings as I am of course looking to eventually pickup a 700e and I would be happy if I could somehow share packs between my 600 and my 700. This added weighted will naturally translate into more current draw and heat, which for sure means some additional wear and tear on packs, but there is some hope.

[rcmike]

I have been thinking of trying this. I have some 3000 Mah packs for my 500 and I have been wondering how they would work.

[akamullen]

Originally Posted by rcmike

I have been thinking of trying this. I have some 3000 Mah packs for my 500 and I have been wondering how they would work.

I have 2 40C 3000 packs as well.. I am going to go on wed. and give them a try. Have had a week of 30mph wind here... Looks like wed it might let up..........

[rcmike]

I have to wait until I get my replacement Ice 80HV before I try it. I have the problem with the heat sink separating.

[trevjonez]

well i fly 3000mah 30c packs on my 600 FBL and they come down pretty warm and are slowly getting puffy but the summer heat has been cruel to them.

putting a 700e together right now so we will see what happens i need to pull the data log on my 600 i think i average around 25 amp draw for a flight with peaks in the high 70's to 80's but my collective management is getting better all the time and is lessening the crazy peaks

[growmaster4]

i fly blue lipo 3000 25c and they dont even brake a sweat after a pretty hard 5 min flight,maybe my motor is a bit easier on the packs than your

[trevjonez]

Originally Posted by growmaster4

i fly blue lipo 3000 25c and they dont even brake a sweat after a pretty hard 5 min flight,maybe my motor is a bit easier on the packs than your

im running a 4025-630 on a ice 80HV. 25 gov gain. 2100 headspeed in idle 2. fly it 5-6 min but it may be running too long i'll go check it all out once im done with my calculus home work.

8pwm and low timing as caslte recommended. the motor is running a little cooler with those settings but im wondering if its taking more a beating on the batteries or if its the govenor gain? maybe i will back it down to 20 and see if i feel a difference. i had to crank my tail gain up to 55% on end points to get it stop a drift i think is related to the gov.

will get back to you later tonight.

also i subscribed to this thread so i will get notifications

[growmaster4]

i run the 4035-560 with the ice 80hv.i get 5.30 tops putting 80 percent back.
i am in outrunner mode with low timing.my motor gets warm but not too bad.i also run low gov gain.
if you think your tail problem is related to the gov try fix end points,that will tell you for sure

[trevjonez]

im too spoiled by the gov awesomeness. looks like i am peaking out at 100 though so i may need to bump up the pinion a little or get a bigger motor but i doubt that.

attached is the data log file in a zip

motor is 630 kv 8 pole. 170t main gear 14t pinion. looks like the last flight was 2.15 watthours so what mah would that be? 2150?

EDIT

also i dropped the gove gain from 25 down to 18 so im hopping that helps me out a bit. i have the head speed change rate at 16. going to order a 15t pinion now though just to continue tuning the setup.

[feudallordcult]

Keep the info coming, guys! This is an excellent topic to discuss because I started a similar one on a 12s 3000mah setup in the rex600. Have been waiting for the arrival of a flybarred 700e at the LHS but w/o any success thus far. may eventually get the 600 but it just irks me when I know that I will be paying good money for a lemon i.e. 100A "fireball" esc.

[trevjonez]

Originally Posted by feudallordcult

Keep the info coming, guys! This is an excellent topic to discuss because I started a similar one on a 12s 3000mah setup in the rex600. Have been waiting for the arrival of a flybarred 700e at the LHS but w/o any success thus far. may eventually get the 600 but it just irks me when I know that I will be paying good money for a lemon i.e. 100A "fireball" esc.

if you want to do a 600 esp and upgrade to 12s just make sure you add the 3rd bearing block. my CF had 3 but i can run stock gear and peak up to 4500+ watts without it stripping out. tic tocs and all the good stuff that people jack their stuff up with has all been fine too.

anyway back on track. i have 4 turnigy 6s 5000mah 20c packs on their way here and in a few weeks i may buy a 2 hyperion 35c 4500mah packs for it if i fly it enough.

i have blown so much money on this already and not even setup my electronics yet i bought 2 protek 40 power supplys and another hyperion duov3 charger to keep my 2 12s birds going all day having the duo was nice but having two is like AWESOME never have to stop flying. spendy yes worth it? some may say no but when you only fly with 1-2 other people and waiting turns is rare yes it is worth it.

[feudallordcult]

Originally Posted by trevjonez

if you want to do a 600 esp and upgrade to 12s just make sure you add the 3rd bearing block. my CF had 3 but i can run stock gear and peak up to 4500+ watts without it stripping out. tic tocs and all the good stuff that people jack their stuff up with has all been fine too.

anyway back on track. i have 4 turnigy 6s 5000mah 20c packs on their way here and in a few weeks i may buy a 2 hyperion 35c 4500mah packs for it if i fly it enough.

i have blown so much money on this already and not even setup my electronics yet i bought 2 protek 40 power supplys and another hyperion duov3 charger to keep my 2 12s birds going all day having the duo was nice but having two is like AWESOME never have to stop flying. spendy yes worth it? some may say no but when you only fly with 1-2 other people and waiting turns is rare yes it is worth it.

dun worry abt it cos I only fly on weekends i.e. twice per week. and if it rains, then it's back to the sim. is it worth it? I'd say hell YA! esp when i managed 10 flights (5 on beam and the remainder on rex500) doing stalled turns, what a RUSH!

[marcosp]

I'm looking forward to hearing from the guys who are going to test their 3000mah lipos during the week.
After the tests we made we checked the Castle ICE's logs to try and find the difference in amps. I don't have the graphs with me since it was on someone else's notebook. I saw lower peaks, with 5000 reaching 110A, with the 2650 reaching around 90A. Hovering was in the 30s, and did not see much difference there which follows logic.

After these first test these guys are going to fiddle with their pitch curves during the week, most probably extending flight time by lowering the max pitch from 12 to something between 10 and 11. If the heli behaves nicely being light, needing less pitch and still flying hard and with 5 min minimum flight time then it's a real finding.

We are talking FBL here which does help, and next step is to re tune the parameters on the FBL units since our guess is the lighter heli should need less force (gains) to hold precise stops without bounces, etc.

Anyhow, I am flying 6 mins with the 5000s. I have no expectations of maintaining that time, but I'd concede 60 seconds for a better flying heli.

[im4711]

Any updates on this? My 700 is still grounded due to the main gear failure. So I soonest could try out the 3000 mAh setup in about 1 week using batteries from my TRex 500.

[XSTAR]

This is great News, keep us posted.

[akamullen]

If I did not live in what seems to be the windiest place in the states I would have tested my 3000 40C batts already.... It's ether raining, windy or both for the last two weeks......... I got to move.....

[trevjonez]

move to utah. clear and calm most of the year so long as you can get out early in the summer to beat the heat.

plus its close to vegas

i flew twice with 5000 20c packs and they flew great and the heli was smooth but blew a bearing out

even with my 120hv esc on the back it balanced just a tiny tiny bit tail heavy but it felt so good flying im not going to worry about it. i bumped up the stop gain to 10 on ele and ail for the 2nd flight and it solved the bobbles it had. such a nice heli to fly im going to have withdrawls till i get a new motor any body try the 600 packs yet? i don't think it will work very well. sorry to be a skeptic. personally i wouldn't go lower than 4000.