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Grumpy
Moderator
Posts: 200
The difference in weight is 66 grams. Very minimal really. That's including mufflers.
July 16, 2016 at 8:56 PM Flag Quote & Reply

kennyglide
Member
Posts: 748

Thanks Greg and Grumpy, i haven't got the plane or the servos yet... so all info i can get is useful..the plane has been ordered.....   i have looked on the net and it is quite common to put .46 motors in them so the jump from there to .55 is minimal around 16 grams from memory .... although i do have a very lightish MACS pipe to fit to it so may save a bit there....  anyway gives me something to think about till i get back to the club again...Mum's still in hospital  and Dad is coping OK .....   :) 

July 17, 2016 at 3:11 AM Flag Quote & Reply

kennyglide
Member
Posts: 748
Hi, going to run 5 standard servos in this Sonic and was thinking of getting a Life Reciever Battery 6V ..(cause they are the lightest) wondering how many mah. Would be required minimum ..? :) also brand and where best to get them..... :)
July 20, 2016 at 8:12 AM Flag Quote & Reply

Mick
Member
Posts: 317
Hi Ken i have 3 life packs and they can be a pain as the equipment we have doesn't seem to charge or check them properly for example when my packs are fully charged the checker (that has a life setting) reads 70% and the charger will over charge them if Im not careful. They also drop suddenly I will use lipos and Ubecs in the future. you would only need a 1000 to 1500 mah 2 cell for a few flights most of my glow planes have 1500 2 cell lipo and might use 10 to 20% in two flights. In my petrol planes I have 2100 2 cell life and I cant tell how much they use but I would guess around 5%.
--
Don't forget to have fun :D
July 20, 2016 at 4:21 PM Flag Quote & Reply

Cel
Member
Posts: 695

Well said Mick...

I use LiFe batteries in a few of my models. One uses a 700ma Turnigy one. The larger ones are ok, but the 700ma one constantly tells my transmitter (using telemetary) that the voltage drops to a dangerous level. The voltage drops because when all the servos move, the current drain lowers the voltage significantly. The bigger LiFe's I have, have the capacity behind them to avoid the dip under load.

Chargers terminate the charge at 7.2 or 7.4 volts (2S), but the battery then drops to 6.6 (or a little above) within an hour or so. My checker is not for LiFe, but gives a voltage for each cell. Trouble with any LiFe battery for us is the flat discharge curve. Fully charged at 3.3 volts (per cell), almost ready to dump at 3.15 volts. That's not a lot of change to allow any checker to detect a half flat battery...


I'm with Mick on this topic. I've been swapping the smaller LiFe's for LiPo's with a BEC whenever I make up an order. I'm pretty confident in saying that all of our receivers (now that we're with 2.4Ghz) are fine running with 8.4 (fully charged) volts from a LiPo. Many servos don't like it though... Some that I've tried are jittering all the time and don't center very well.


I'm using a couple of 850mAh Lipo's in my smaller models. 2 or 3 flights (30 - 40 minutes or so) use less than 150mAh's. Many of us remember that 500 and 600mAh Nicads were the norm in 60 size models only a decade or so ago.

--

I love Eklectric powered things... my phone, my cordless drill, my toaster, my shaver...

But that's where it ends!! THINGS THAT FLY NEED REAL ENGINES!!!   :D

July 21, 2016 at 12:07 AM Flag Quote & Reply

kennyglide
Member
Posts: 748
Thanks for the replies... i have considered useing 4 cell eneloops instead of 5 cell eneloops as a way of saving weight ...i am using 5 standard HiTech analogue servos ..any thoughts?... :)
July 21, 2016 at 8:12 PM Flag Quote & Reply

Cel
Member
Posts: 695

Check to see if your receiver is ok with 4 cell Nimh... I've found that Spektrum receivers brown out or don't work at all with 4 cells.

--

I love Eklectric powered things... my phone, my cordless drill, my toaster, my shaver...

But that's where it ends!! THINGS THAT FLY NEED REAL ENGINES!!!   :D

July 21, 2016 at 9:05 PM Flag Quote & Reply

Tony D
Member
Posts: 39
I use four cell eneloop with spectrum and futaba receiver's with no problems running up to 7 servos Ken
July 22, 2016 at 1:02 AM Flag Quote & Reply

Cel
Member
Posts: 695

Hmm... I must admit, I've only ever tried it on the club trainer's receiver. Maybe each one's different.


--

I love Eklectric powered things... my phone, my cordless drill, my toaster, my shaver...

But that's where it ends!! THINGS THAT FLY NEED REAL ENGINES!!!   :D

July 22, 2016 at 3:09 AM Flag Quote & Reply

GBAR
Member
Posts: 688

When useing Nimh batteries either 4 or 5 cell I always test mine with a load tester. They might appear fully charged(surface charged) but when you test them under load such as a series of servos, they will either hold their charge or discharge too at least  45-50% of their capacity, so you need to recharge them, which is a pain in the a---e but at least you know the battery won't fail. Spektrum recievers will handle up to 8v or 9v and then disperse the voltage to a 6v across the board evenly so I have been told, never actually put a multimeter over the wires to check it out. I have noticed a bit of a servo flutter when fully charged but after a couple of minutes settling down.

July 22, 2016 at 5:07 AM Flag Quote & Reply

kennyglide
Member
Posts: 748
Phew i think my head is going to explode.... thanks everyone i've got the info now all i have to do is nut it out ..... :)
July 22, 2016 at 8:45 AM Flag Quote & Reply

kennyglide
Member
Posts: 748

Just wondering if an Eneloop 6V AAA  5cell  800mah flat pack would do the job for 5 standard analogue servos and a Sprectrum 6 channel receiver? About  a 45gram weight saving on the AA's. Says on the box recommended receiver battery is   4.8- 6V /800-1200 mah .....      :)

July 24, 2016 at 9:29 AM Flag Quote & Reply

Cel
Member
Posts: 695

That will be fine Kennyglide. Just be aware that the current drained from your battery will be higher due to the higher voltage levels. Despite this, you will get bored flying it before tha battery gets to a dangerously low level...

Like GBAR said earlier, only trust a battery checker that places a load on the pack, otherwise it will show full charge when it only has 10 or 20% remaining...


I wouldn't have any fear in using 6v AAA's of that capacity.

--

I love Eklectric powered things... my phone, my cordless drill, my toaster, my shaver...

But that's where it ends!! THINGS THAT FLY NEED REAL ENGINES!!!   :D

July 25, 2016 at 1:18 AM Flag Quote & Reply

kennyglide
Member
Posts: 748
Thanks Marcel... i'll get the 800mah 6v pack ... :)
July 25, 2016 at 9:02 AM Flag Quote & Reply

Cel
Member
Posts: 695

What happened to the Nemesis Tony?

--

I love Eklectric powered things... my phone, my cordless drill, my toaster, my shaver...

But that's where it ends!! THINGS THAT FLY NEED REAL ENGINES!!!   :D

August 3, 2016 at 7:55 AM Flag Quote & Reply

Grumpy
Moderator
Posts: 200
Hi Marcel, I'm sure Tony can explain what happened but it appeared that it was maybe a battery problem. The damage to the fuselage was fairly terminal but the wings and tail section survived and will be resurrected as a large control line trainer.
August 3, 2016 at 9:10 AM Flag Quote & Reply

kennyglide
Member
Posts: 748
Just wondering ....when fitting servos i imagine it would be best to keep them well insulated and not be touching any part of the wooden mount as that would allow vibration to travel through the servo...that means i would have to carve out the mounting to ensure no plastic to wood contact..is this the normal routine? or not really a problem? :)
August 4, 2016 at 8:38 AM Flag Quote & Reply

GBAR
Member
Posts: 688

Just discovered that I left a battery hooked up in a plane since Sunday, even though the isolating switch was off the ESC was still armed to the battery. The battery is a Bonka 4sx3300 and was dead flat, hooked it up to the charger and charger alarms went off telling me absolute no voltage. Hooked battery up to test meter, dead flat, hooked battery to another battery piggy back and left for 4 minutes. Came back un hooked battery and stuck on charger straight away. Charged at 2.2amps for 120mins, perfect, each cell is even, battery is at peak capacity, left for an hour and retested, perfect. If that was a Turnigy battery it would be in the bin, these Bonka batteries are a bit more in price but worth every cent. Will be buying more from Wolf.

August 11, 2016 at 5:25 AM Flag Quote & Reply

Cel
Member
Posts: 695

Wow... I've done a similar thing with a couple of Turnigy ones. One was in the club's simulator transmitter while someone was borrowing it and it ran down very low. The other was the same scenario as GBAR. ESC sucked it dry. Both were Turnigy, one is still ok for the transmitter, but a cell drops voltage more than the others under load and the other has one cell that is hopelessly short on capacity and current rating. 


One day I'm going to charge the dud one up then puncture it, as that's the closest we can get to legal fireworks!! My boys will love it!


See... LiPo's are actually fun after all!!


Just for the sake of having a little dig, once I accidentally left fuel in the tank of one of my planes after flying it... Guess what happened when I went to fly it next!?

First person to answer correctly gets a free 9 inch nail to make their own fireworks on New Years Eve!!

--

I love Eklectric powered things... my phone, my cordless drill, my toaster, my shaver...

But that's where it ends!! THINGS THAT FLY NEED REAL ENGINES!!!   :D

August 11, 2016 at 7:28 AM Flag Quote & Reply

Grumpy
Moderator
Posts: 200
It would have blown a little more smoke due to the methanol evaporating slightly. Or maybe just the fuel tank went flat, lol.
August 11, 2016 at 8:02 AM Flag Quote & Reply

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