dasintex

My Feedback: (10)

I am building a 60 size H9 warbird, with stock H9 Mechanical retracts; I have never used Mechanical Retracts and have always opted for Pnuematic Retracts on my other Warbirds; I will be running a 1600 Mah Battery; I will be using Robostruts to lessen the chance of the wire gear bending and hanging up, and I will make the assumption that I will have the linkage and endpoints and travel on the retract servo correct with no binding or buzzing, etc; is it nessesary to go with a separate retract Battery?

Thanks.

DavidAgar

My Feedback: (108)

I have never used 2 batteries on any of my mechanical retract planes and never had any issue's as a result of a power loss. Good Luck, Dave

dasintex

My Feedback: (10)

David; Thanks for the reply, quick question, what size battery do you use, is the 1500 Mah I plan on using plenty?

p39

My Feedback: (5)

I've got a 1500 mah pack on my H9 P47... the big one and use the mechanical retracts and get 3 good/safe flights out of the charge. After that there's still plenty of power left but I'll field charge then.

JL1

My Feedback: (93)

I tend to disagree. I use a seperate battery with mechanical retracts for one general reason, mechanical obstructions. In the operation of a model there are a lot of things that can happen to obstruct retract operation. Foreign objects acquired during takeoff, any loose object floating around in the models structure (that screw you never could find), temperature changes effecting the linkages, age and wear of linkages, etc.
If a "jam" occurs during a retract cycle, unless it is fused, your servo current is going up in a big, big way and you discharge a battery in a few minutes. Instead of damage from a belly landing, you loose the whole model. A seperate battery need not be vary large and adds minimal weight to a 60 size and up model. To me, it is good insurance for a low cost.

p39

My Feedback: (5)

That's the beauty of these forums. I disagree with you. I've never had a retract servo stall. Sure you need to do preventative maintenance.... check them over before you take off to make sure they're working properly, but you do that anyway, right? And that rattle from the lost screw... if you hear that when you're putting it together, you find that anyway before you take off, right? As far as age, linkage changes, wwear and tear, you'll notice that before you take off anyway on a preflight. If you add a little bit of bend in the linkage anyway, it will also give you a bit of a mechanical buffer to absorb and play in the system. If you see a retract hanging down after take off you surely don't fly an entire flight anyway do you if you're worried about a stalled servo? Simplicity seems to be a good thing where a mechanical retract system is involved. They are or can be a pain enough.

dasintex

My Feedback: (10)

I was hoping for more people to lend their opinion, but out of 3; 2 have suggested that a 2nd battery is not needed, I suspect that this may be the trend even if 50 people had chimed in, one of my goals was to build this plane light and simple, so I think the single 1500 mAh Battery will serve my needs.

Thanks, Guys, and if anyone wants to add to this discussion I certainly would welcome it.

Rodney

I agree with JL1 as, if anything can go wrong it eventually will. The two battery setup is far more reliable and more apt to recover from the unexpected when it happens. If you can stand the weight of the extra battery and harness, go for it.

jaka

Hi!
Using just one battery is asking for trouble! What happens if one landing gear leg gets stuck in the wheels wells do you think?
The second battery could just be a small 400mAh 4,8V NiMH battery. I use one of those on my DC-3 and it works fine.

p39

My Feedback: (5)

If anything can go wrong- it eventually will... but adding one more piece and wiring to go wrong is kinda counter to what you're saying isn't it? An extra battery pack in a .60 size airplane make a big difference on how they'll be handling. Light wing loading in a warbird is key to some better flight characteristics.

p39

My Feedback: (5)

Been flying warbirds and rc since the mid 70's. Never used a separate battery pack, never would consider it. Maintenance, pre-flights are the key to bringing her home safely.

JL1

My Feedback: (93)

Oh! I hadn't thought about that. If it has never happened, it never will. Good thinking

WALKERS210-RCU

My Feedback: (36)

There was an issue with servos for the H9 war birds that I encountered about one year ago. Using a 6volt system the retract servos would not function, however put a 4.8 pack in worked perfect. There is a few post here on RCU about the problem and the common solution was to use a separate 4.8 volt battery pack for the retract servos and modifying a Y harness, clip the RED lead going back to the receiver. But for most cases I myself have never saw a need of a second battery pack just for that.

p39

My Feedback: (5)

Now you're catching on JL1. Hey..... wait a second..... could that be sarcasm?

Boomerang1

I have only one model with mechanical retracts but it's a big electric model with a seperate reciever battery. I tapped off the flight batteries via a voltage regulator to run the retract servos in case the retracts stall a servo. - John.

RVman

I don't use a separate battery either. I put ball links on the servo end and if something tries to stall the servo, the links will pop off with no harm. I also use only the JR791 as it is powerful enough to break something before it will ever stall.

LuftwaffeOberst

Me too, I only use one battery and when I have flaps and a Mechanical Landing gear I use a slightly larger battery. A 700mah will work but a 1400 mah NiCd is better. You don't need two batteries if you know what your doing. ( Not insulting anyone so please don't be offended.)

I have a JR791 as well, and he's right when RVman says it's powerful enough to break something before it will ever stall. That Servo is well worth the money. If you take the JR791 Servo and take it apart, you will see ball bearings and all metal gears. With this Servo you will not have any issues with your retracts deploying.

Some people also beef up there Push Rods for extra toughness. But Hanger 9 makes good ARF's and I always used most of there stock hardware without having any issues what so ever.