Is it okay to use a 5 cell nicad(6v) without a regulator?? as I have seen that futaba ( non-digital) are much faster with a 6v , but I am unsure if a regulator should be used as a fully charged 6v would be a lot more than 6v. anyone know???

I don't use a regulator with mine and don't have any problems.

As far as I know it does fine. I have heard that some people put a regulator on them becuase the get hits, but mine works fine without. If you are buying one I would recomend you get a NIMH the are so much lighter. I just got a 1650ma NIMH on my U-Can-Do and I like it. Good Luck...

thats good news then , but what is strange is that 90% of people i know still use 4.8v , why isnt everyone using 6v with all the increase in speed and torque you can get by using an extra cell!!!!

6 volts do cause more wear on the servos, that could be a reason. Another factor might be the weight of the 5th cell, however you said you are using a nicad- if you use a 6 volt NIMH it will be close to the weight of the 4.8 volt NICAD... so take your pick. I think they say the weight to power ratio comparing the NICAD and NIMH is 1:3

oh, and here is a link to Radicalrc where he talks about NIHM and NICADS... http://members.aol.com/davthacker/nimhfaq.htm

And here is one about 4 cell vs 5 cell...
http://members.aol.com/davthacker/4or5cellsfaq.htm


hope that helps...

There will be a slight drop in flying time when using a 6V pack due to higher current drain compared to a 4.8V pack, but that can easily be overcome by using higher capacity packs.

Thanks , great help , but as for burning out servos , is this a fact or is it a myth , as if it is fact then i can see why most people stick with 4.8v

Yes, and no...

Naturally when something works harder it wears out faster, it doesn't actually burn out the servo the next day or anything. I have seen people using 6v packs and servos that have had been in planes for at least 500 flight and still no problems.

The advantages of using a regulator on 6V is that you will have consistent Voltage throughout the drain of the battery. After a charge, you may see voltage of over 7V..
If you regulate them down to say 5.7 they will stay that way from the first flight till whenever they get below 5.7V
Servo speed will always be the same throughout the drain and you wont have jittering servos after a full charge.

A regulator is so easy to install I am not sure why people dont use them.. Its as easy as plugging it in...

A glider champion told me that Nmihs were a bad idea, because they have a significantly larger voltage drop when placed under load when compeard to Nicads. The problem with this is that when you do a snap roll or lower the flaps, the current drain from the high performance servos put a large load on the battery........ the voltage supply goes down so much that the reciever goes into failsafe or it goes out of range- hence broken model.
I do not know wether this problem occurs at 6 volts though.
Maybe it doesn't, but im sticking with good old nicads.
Luke

I assume that with all the latest Nimh technology that hat is surely a thing of the past as there is now way they would be used , but interesting thought though

From what I understand he voltage doesn't drop that easy. It takes a little time. If you were running an electric motor you would want to use NICAD instead of the NIMH. The NICAD would last longer in this case. Maybe we should do some research and see where the two curves cross. Find what point they cross and at what kind of load makes one better than the other.

PS the RX goes into failsafe when the battery is low(just pulling the plane to idle and can be brought back up by cycling the throttle) They say you don't get a complete lockout until about 3.7 volts, but I have flown down to 3.62 volts before. At that low voltage I was getting intermittent lockouts when I feed movements, perhaps when it was at neutral the drain was not enough to drop below the 3.7 threshold.

I have 2 airplanes running 6v NIMH cells and 1 6v nicad and they all do great unregulated. The high surface charge (normally around 7.2) will scrub down to about 6.5 with load, after only a few minutes of operation. Even the aa pack carries 1650 ma(nimh) so you have power to spare in most instances. I have noticed they seem to self discharge a little faster than nicad while sitting. Nothing wrong with regulation if your looking for that perfect unchanging setup, but I prefer the KISS principle
(keep it simple stupid)

From personal and extensive experience I'd state that 6V flight packs (NICAD or NiMH ) are absolutely fine.

Why introduce a regulator when they are allready present in the RX and in some servos. Servos are faster and stroger on 6V, most manufacturers give specs for 4.8 and 6V.

If you wear / burn out a servo because running on a six volt supply then the servo was not man enouh for the job and would have been totally inadequate on 4.8V

Re battery capacity - see the servo manufacturers data on current consumption and rate batteries accordingly

current per servo x N servos = capacity in Mah

eg 500ma, x 4 = 2000mah, a 2000 mah battery will keep these servos happy for 1 hour, probably much more as you will not have all servos working at full power all together.

My Weston (Super) Couger has a 6V 600mah Nimh battery, after 4 10 - 12 min flights it usually takes c200 mah to recharge. I am using Futaba 9102 (ele), 9202 (rud) and 2 x JR 591 servos (ail)plus a hitec hs 81 on throttle.

Yes servos jitter a little on first power up after a charge but they soon settle down. Its not an issue.

Wayne, can you give us some tips on looking for a regulator?

Where to look?
What to look for?

Maybe an example unit that you use with good performance?

Thanks,

I'm with Smallfly on the KISS principle. I purchased and installed a regulator for my 30% Edge from one of those advertisers in RCM or MAN. Setup was 2700 mah 5cell 6.0V NiMh input into the regulator and for output I got ....ZIPPO, NADA, ZILCH, ZERO volts.
So I sent it back to the mfg and they sent me another unit. It's still in my parts drawer. Why install another component that may fail? (a single point failure here would mean lost airplane, unless you add redundant battery system).
Most of the IMAC guys I talked with do not use a regulator with the 6v packs (They seem to need to regulate the fancy Li-Ions and Li-Poly though due to the much higher voltages).
Just keep it simple.
I still run all my heli's on 4.8 V as I don't have enough info in regards to the gyro and super speed servos and how they'll withstand the higher voltage of 5 cell packs.
Any heli guys out there flying with 6V packs? Regulated for the gyro and/or high speed servo?
Any info would be appreciated.

Ann Marie from futaba once told me that all there receivers are rated up to 7.4 volts. A fully charged 6volt pack will do just fine.

Like Wgeffon mentioned a regulator will give you constant servo characteristics throughout the day but this will only be noticeable on more advanced type aircraft flown by more advanced type fliers..

I run 2 6volt NIMH 1650 packs plugged right into the receiver with hitec digitals and the run great.

A Regulator is a 3 pin chip which so long as you supply it with a voltage above say 5.7 V will supply a nominal 5V. ALL modern RC rx have these built in (as do some servos)as a lot of airborne sets are used with dry cells (yes still) and 4 x fresh new dry cells will give 7V or maybe a bit more.

Don't worry about it, you wont burn out a servo unless your control runs are tight otr the servo is wrong for the application. Check your batteries after a couple of flights or use a battery monitor.

6V is good!

My 6V batts are Powerflites. As someone else said, they are 7.2V batts and on a full charge they will be 8 or above so a regulator is needed.

There are two types now on the market. Constant V and adjustable V regs. I am using a constant 5.7V reg.
I have never used the adjustable so I cant give you any info on them..

Jaico, Jomar, Skyborn Electronics are some of the brands out there. Horizon also has some under one of the comapnies they distribute. I cant remember the name right now.

All you have to do is plug them in-line between the switch and the RX on the lead that goes into the RX. Not the battery side.
When I check voltage I am reading the un-regulated battery under a 1amp load.

I also think ( I may be wrong ) that I get longer battery life with the regulator because the servos are always operating at 5.7 instead of 6.8, 6.7, 6.5, 6.2, 6.0, etc etc.

Lots of people use them and lots of people dont. Its a matter of using what your comfortable with and not using what your not comfortable with.
This hobby isnt black and white... There are a million ways to do most things.

I also use the regulator on 6V batteries. I like the constant voltage. Like Wayne said, it just plugs in between switch and receiver. Nothing else to it. Weight is minimal too.
I like the ones from MPI or Central Hobbies.

BTW guys, Batteries America have a 2000 NIMH pack in AA size. Radical RC has only the 1650. Batteries America now offer the white JR plug for the newer JR Transmitters. I bought a 9.6V 1650 NIMH pack for my tx, and you can fly a week on that pack. Awesome.
I am not trying to trash or downgrade Radical RC (I am a customer there too), but found the packs from Batteries America a little more attractive as of now, and thought I pass on my experience.

well i have orderred a couple of 1300mah NiMh receiver batterys , i will not try the regulator unless this twitching issue at full charge is a problem , i am looking forward to see what difference it makes esecially with some futaba 3001 ball bearing servos , according to futaba website they should be 50% faster and a lot more torque , what a great way to get fast servos cheaply!!! Oh why didnt i try this sooner!!!!!!!!

What is the safe operating voltage range for a 6V NiCd battery before recharging is needed ? I know that for a 4.8V battery, anything below 4.8V is not safe for the receiver. Is it safe to run the 6V battery until 4.8V ? Thanks for the inputs.......

You could run it down to 4.8 if you wanted to, but after the battery drops a little below 6 volts it's discharge curve is much steeper. It is not advisable, but I have done it by running shorter flights and checking the battery often once it is below the 6 volt.

Does anybody sell a reliable on-board battery monitor for 6V ? I was thinking of modyfying my 4.8V monitor by adding a resistor but it needs to be calibrated.

You might check www.i4cproducts.com - I haven't used them personally, but their stuff looks pretty nice.