RunRyder - Why Run a regulator ??????

rrTV-PHOTO

New HD TV

HOME rrTV-PHOTO GALLERIES MY GALLERY HELP-FAQ

myHOME PM pmRR MEMBERS 630 ONLINE 41 EVENTS SEARCH REGISTER START HERE

2 pages [ << < ( 1 ) 2 NEXT >> ]

737 views

POST REPLY

HeliHobby	.	Ron’s HeliProz South	.	Century Helicopter
	.		.

Main Discussion > Why Run a regulator ??????

Blade_Master1
Veteran
Location: Canada

I am currently running a normal 4.8v a 1450 ni-cad rx pack

which operates
3 5625MG Hitec
1 Blue bird HS servo Ya I know it's not the best servo but ...
How about using a HSG-5083MG instead of?
it is a micro tail servo has a speed of .07sec @4.8v with 21oz of torque

also running a 401 & 9254 tail

I get anywhere from 4-5 flights so far from a charge

Why are people using high volt systems?

why do you ?

JM2C's :)

07-18-2008 11:36 PM

Dood
Elite Veteran
Location: America's Dairyland

Faster, higher torque servos, and consistent performance.

And Lipos are lighter than NiMh and NiCD batteries, meaning you can get a higher capacity battery at equal or less weight.

Also, when using a Lithium battery, the regulator is necessary to get the voltage down to a safe operating voltage to meet the ratings requirements of the electronics.

"El Dooderino" if you're not into the whole brevity thing.

07-18-2008 11:44 PM

HOMEPAGE

rookie5
Veteran
Location: Harlow, Essex - United Kingdom

i'm also running my system at 6v mission cell lipo 3000 mah with arizona regulator.

im running 6v system for all the reasons Dood mentioned

07-19-2008 12:15 AM

AltecLansing
Key Veteran
Location: Under the tire of a truck

the amount of power used from a battery will vary depending on equipment. I found the nicads and nimhs and 4.8 volts would last me only 1 or 2 flights before my receiver went into fail safe mode and go to low throttle. This has caused hard landings and crashes for me. I use about 300mah of power per flight with my set up. I now use a regulator and a lithium ion battery rated at 5200mah. I recharge at 8 or 9 flights and have not gone into battery failsafe since the switch. That saved me a bundle of money from crashes caused from unexpected battery fail safes.

Man, I miss the eighties.

07-19-2008 12:39 AM

Yug
rrProfessor
Location: UK. Herts

There's nothing wrong with using NiMH or Nicad cells as they require a nice and simple wiring arrangement. The most important thing you can do is use high current power cabling and good connectors (which also applies to regulated systems) so as to reduce voltage drops and possible brown outs. With moderate digital servos, you can get as much as 3v drop spikes with standard JR/Futaba cable and conectors. High current cable (19A multistrand) and deans reduce this to 1v.
You also have to bear in mind the internal resistance of the packs you're using. 4100mAh has around 3 milliohm while 3000mAh is 5 milliohm and that's for sub Cs. The AA packs are substantially more.
The use 2S lipos or Li-Ions has a four-fold advantage......
A good regulator will deliver a constant voltage to the servos which means that performance is consistent.
It also provides the opportunity to provide the swash servos and tail servo with optimised voltages so they are operating at their optimum performance.
Many regulators are 'enabled' via a switch which doesn't pass the main power, but rather the 'on/off' switch simply enables the regulator to generate an output, usually by way of a FET. This has the major advantage that the switch is going open circuit due to poor connection or broken wires/connector allows the regulator to be in the enabled or 'ON' state. This allows the use of conventional slide switches as well as 'flag pole' switches.
For those wishing to get the peak performance from servos such as 8717s, they can power the servo via the battery 7.4v direct while a regulator is used to derive 5.3v for the gyro and tail servo. Most good tail servos are specced to 4.8v which in reality translates to 5.3v for absolutely safe operation. This largely boils down to the fact that manufacturers are expecting a system to be powered by a basic NiMh 4 cell pack at a base level, which when fully charged, generates around 1.35v per cell.

Vegetable rights and Peace

07-19-2008 01:23 AM

tukkus
Heliman
Location: ma

I simply like the 7.4v lipos/li ions because they charge much quicker

07-19-2008 02:11 AM

Pull-n-Pitch
Veteran
Location: Mt. Dora, Florida (USA)

Blade_Master1--
Besides all the listed above responses to as you say "High Voltage" there is another reason...

Enter in the type of flying you enjoy or are doing!

Remember the more you move a servo the higher the current MAH draw is, so if you are just hovering around and into easy forward flight you are not moving the servos as much as somebody that stick bangs hard 3d for the duration of their flight....
Now my reply isn't meant to criticize your flying or others flying, You may have NO need for that instant servo twitch and prolonged life from your battery due to the nature of your type of flying....
You posted you are able to get 4-5 flights out of a pack, this simply means you are "drawing less" from the battery vs. if you were in the air doing competition level 3D... (servos thrown lock to lock)
Find the battery that suits your flying and have a great time!!

Pull-n-Pitch

07-19-2008 02:18 AM

tarzan_eb
Senior Heliman
Location: Central Illinois USA

why regulate

You don't have to really run a regulator on 30/50 size machine because you use lower voltage servos when you start getting into preformance issues and higher voltage servos you will need more power to those servos. you can't run high speed/torque servos on a 4,8 battery because the servos suck the battery down to fast thats why people run a regulator so they can run a 7,4 battery or 8 volt setupor even a 11.1 volt setup

Fly it ! Crash it ! Rebuild it ! Repeat as needed !!

07-19-2008 02:29 AM

Blade_Master1
Veteran
Location: Canada

So why don't people just use a 6.0v or 7.2v ni-cad ?

how much would I realy save in weight with li-ion and a reg

if I 'm using 3 HSHT servos, 1 miniHS servo and a 9254
how many amps could I be drawing from just tossing the heli about ?

1 last thing if I was paranoid could I use 2 4.8v rx packs?

JM2C's :)

07-19-2008 03:59 AM

TulOkFly
Senior Heliman
Location: Tulsa. OK - USA

LiPo batteries are much lighter than an equivalent voltage and MaH NiCad or NiMH pack.
By running a high voltage pack with a regulator you get a consistent voltage to the servos. With a 6V nicad pack you drop below 6V fairly quickly and the voltage continues to drop with each flight, so the speed of the servos changes.
In general you will never pull more than 5 amps on the servos. With your setup it is probably 3A or less. A 10Amp reg is what I use.

A 7.2 V NiCad pack would be six cells and probably (I am guessing)weighs 3X or more than a LiPo 7.4V Pack.

Just Fly!!!
TRex 450
Blade 400
MX450XS (parts machine now)

07-19-2008 04:49 AM

w.pasman
Elite Veteran
Location: Netherlands

Quote
Why are people using high volt systems?

I reverted to regulated to get consistent tail performance

When I used 4.8V nicad (long ago) the first two flights I did simple hovering 'to get warm' and the gyro was working great because the voltage was high. Then I proceeded with more agressive flying and the gyro was working already a bit less optimal. Then, fully warmed up, I proceeded to 3D only to find that the gyro was not working good anymore because the voltage had dropped too much.

07-19-2008 12:27 PM

HOMEPAGE

w.pasman
Elite Veteran
Location: Netherlands

Quote
So why don't people just use a 6.0v or 7.2v ni-cad ?

Because
(1) my electronics would burn out at 6.0V
(2) because the voltage drop during the day would still be present, degrading performance during the day.

BTW I think the max voltage of 9254 is 5V

07-19-2008 12:31 PM

HOMEPAGE

w.pasman
Elite Veteran
Location: Netherlands

Quote
1 last thing if I was paranoid could I use 2 4.8v rx packs?

Depends on what you want to achieve.
Redundancy? Yes with NiMH but a broken NiCd makes a short-circuit and the other pack in parallel would just effectively be shorted out (which might even cause further damage to both packs).
Extra capacity? Yes but why not just by a bigger pack then?

07-19-2008 12:34 PM

HOMEPAGE

Blade_Master1
Veteran
Location: Canada

I was thinking redundancy if I were paranoid about Batt failure

JM2C's :)

07-19-2008 01:33 PM

bigdog714
Senior Heliman
Location: Chardon, Ohio U.S.A.

I started out as an EP guy using BECs and I have stayed with it on my nitros. I use a CC BEC it is programable from 4.8v to 9.0v, I fly a 6.0v system. The CC BEC with a 3S 2100mAh lipo delivers 7amps, you just have to be aware that with Spektrum RXs the pulse wire on the BEC will cause the RX to re-bind, either run it through a switch, or use a small extention and cut the pulse wire. Once my skills have improved enough for JR 8717s, I will be set for 8.0v constant for the servos, all I need is a Spektrum regulator for the Gyro and Gov. With the 3S 2100mAh lipo I get six 10min. flights, and the battery is in the high 20s.

Align T-Rex 600EP
Align T-Rex 600N
EVO 90

07-19-2008 04:14 PM

mchammer
Veteran
Location: California,USA

Quote
So why don't people just use a 6.0v or 7.2v ni-cad ?

you could and some people do.you must have servos and electronics that can handle the higher voltage though. as already said it provides more consistant and faster servo performance. the only reason not to do it with nicads is that your battery is alot lighter if you use lipos.

all that said if you are not thrashing the thing around I would just use a 4 cell nicad and keep it all simple.if you are pushing the heli to its limits you would notice a big difference with more and/or regulated voltage.

Peace Through Superior Firepower!!!

07-20-2008 08:20 AM

MikeC
Key Veteran
Location: Wausau, WI

Quote
all that said if you are not thrashing the thing around I would just use a 4 cell nicad and keep it all simple.

Like he said, a 4 cell NiCd or NiMH is all you need if you're not really bashing the sticks with lots of servo travel.

My choice to use a NiCd battery on my Swift instead of a BEC was recently considered risky by someone here on Runryder. So I decided to hook up my EagleTree Systems Elogger to my RX battery to show what the draw is on my particular system.

Ignore the middle green trace. That's my head speed which I was not recording on this flight. The bottom trace is current and the top is battery voltage.

Clearly in my case the demands on my electrical system are low. I was amazed when I saw how low the peak current was. I expected it to be peaking at an amp or 2. I run 3 of the 5625MG and a 9650 tail servo.

Mike

Century Swift, Hirobo Sky Robo, Spektrum DX7

07-20-2008 01:29 PM

bigdog714
Senior Heliman
Location: Chardon, Ohio U.S.A.

Hi Mike, what kind of head speed do you run?

Align T-Rex 600EP
Align T-Rex 600N
EVO 90

07-20-2008 03:00 PM

bigdog714
Senior Heliman
Location: Chardon, Ohio U.S.A.

Quote
4.8 volts would last me only 1 or 2 flights before my receiver went into fail safe mode and go to low throttle.

I am not the only one with consernes

Align T-Rex 600EP
Align T-Rex 600N
EVO 90

07-20-2008 03:07 PM

AltecLansing
Key Veteran
Location: Under the tire of a truck

I don't fly 3d, but with digital servos, I recommend a regulator with a lithium ion pack. The 4.8 volt packs never worked for me on my evo 50. They do however work on my 30 size helis that have analog servos.

Man, I miss the eighties.

07-20-2008 03:09 PM

2 pages [ << < ( 1 ) 2 NEXT >> ]

737 views

POST REPLY

MTA Hobbies	.	Model Rectifier Corp	.	PowerHelis
	.		.

Main Discussion > Why Run a regulator ??????

UPDATE SCREEN PRINT TOPIC

Advertisers

Subscribe to This Topic