Another 12S story

[snjbird]

OK guys,

Just did my first days worth of test on my 12S conversion...

Jury is still out, I can feel the weight of the batteries when I am doing autos... Here is the first setup I tried

CC85HV set RPM mod...
Normal 1900
ST-1 2000
ST-2 2100

Scorpion 4025-630... 15T
Temp 125
FT 2:00


Batteries 2X Flightmax 2650 30C
Temp 99*
mAH 595
23.05 V


Todays setup...
set rpm
2000
2100
2200

14Tooth

[rceccleston]

15T is a little over geared for the 4025-630 in governor mode.

You'll get the same head speeds with 13T@100% throttle in fixed end points, with a cooler motor and longer flight times.

I run 12T@100% throttle and get 6.5 mins on 12s (2x6s) Turnigy 3000Mah 30/40c packs.



I used to get 4.5 mins on 14T governed on the Flightmax 2650 30/40c packs.

[snjbird]

Just did a 2:00 flight in the front yard,

batteries 99*
23.65 volts

motor 125*

ESC 89* just over ambient

HS very smooth and stable

I was doing piro flips and tic tocs

and backwards loops, with some full collective climes...

I need an eagle tree

[OnTheSnap]

With the same setup on 13T I'm at 2300 RPM @ 100%. The Castle s/w assumes something like 80% eff, but this setup is more like 90+. I run 2100 fixed rpm and it holds the headspeed great through any hard collective maneuver.

[snjbird]

I like my best at 2250... seems to be a great combo of power and stability, any faster and it is very pitchy... any slower and it does not have the pop I like!

[snjbird]

I've done 3 test flights today...

I think this is the sweet spot, I'm getting great power, and the packs are going up 30* in 3:30, they are topping out at 120* but it is hot here, 89* now....

I have had enough of the guessing game, I pushed the button on an Eagle tree, should be here in the morning post! now I just have to learn how to use it!

[Rotorcraft]

Stick with 2250, that's what I am at for H.S. and find it to be the sweet spot. Anything higher and I feel like the flight time/"pop" ratio goes down.

Did you get the brushless RPM sensor to go along with? That will make tuning anything you want a breeze! You will be amazed how well this "non-stop bashed" governor mode works.

Anyways congratulations on another new HV setup! Got some pics?

[snjbird]

Got to the field today, man it was sweet to fly this machine were you can let her off the leash! I didn't have the data logger yet, but I am very pleased with the upgrade in performance from my 8S setup! great smooth power reserves. fast and sounds awesome!

[Shef]

What about flight time?

[rceccleston]

Originally Posted by Shef

What about flight time?

I used to fly 14T in set gov mode at 2000rpm with Flightmax 2650Mah 30/40c packs, flight time was only 4.5 mins with time to land, but packs were very warm and made the heli a little tail heavy too.

Now run 2100-1950rpm on 12T at 100% throttle. Would get 5 mins with Flightmax 2650Mah 30/40c packs or current 6.5 mins with Turnigy 3000Mah 30/40c packs. CG is spot on too.

[Shef]

could you please post a photo? I'm really curious to see how you're mounting the double packs.

Thank you

[rceccleston]

Originally Posted by Shef

could you please post a photo? I'm really curious to see how you're mounting the double packs.

Thank you

As shown below, after loosing a single pack due to a crash, it became apparent the stock battery mount orientation was flawed when carrying 2x 6s packs for a 12s setup.

In the crash, the leading edge of the frame dented the 3rd cell, causing the cell to swell and later discharge fluid.



This clean mod allows both packs to be installed within the frames and should hopefully provide better protection in the event of a crash.



Both original top screws have been used, to mount the battery tray, and new holes drilled below to mount the tray vertically.

[rceccleston]

You maybe interested in my recent mishap..

https://www.helifreak.com/showthread.php?t=171262

[Shef]

thanks for sharing the pics....would love to see the video. As soon as my 6S packs go, I might have to make the 12S move too. Flight time is similar, right? It's just the power that's massive, right?

[rceccleston]

Never ran stock 6s due to reports of hot motors / esc and short pack life cycles.

Doing loops, rolls, tic-tocs, rainbows etc for 6.5 mins with cool power system with no regrets.

[akouzmit]

Another way to mount packs with still balanced heli:

[dieselracer]

Originally Posted by rceccleston

As shown below, after loosing a single pack due to a crash, it became apparent the stock battery mount orientation was flawed when carrying 2x 6s packs for a 12s setup.

In the crash, the leading edge of the frame dented the 3rd cell, causing the cell to swell and later discharge fluid.



This clean mod allows both packs to be installed within the frames and should hopefully provide better protection in the event of a crash.



Both original top screws have been used, to mount the battery tray, and new holes drilled below to mount the tray vertically.

Where did you get the upgraded screws for the heli?

[snjbird]

Got a video today, it was not the best flight and I lost the camera man a few times doing some new stuff he was not used to...

11 1 09 Trex 600 12S (3 min 40 sec)

We did 6 flights on this setup, packs were never over 120* I was able to fly charge and fly again, I'll get a couple photos soon.

3:30 has been the magic number for flight time Shef, the packs could handle more flight time temp wise, but I'm pulling 1950 to 2100 out in that 3:30 so I need more mAH to get a bit more flight time...

[rceccleston]

Originally Posted by dieselracer

Where did you get the upgraded screws for the heli?

Stainless steel bolts from eBay or hardware store.

They have a larger head than the stock bolts so will be less likely to strip.

[OverTemp]

snjbird... what headspeed and pinion? I'm only putting 1650-1850 back in my packs after 4:10 flights... this is with 3000 packs... could get over 5 minutes and stay under 2400. The punch on our birds look similar and flying styles are somewhat comparable.