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Some Questions

Old 01-11-2010, 06:34 PM
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F-18
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Default Some Questions

Sorry but here are some more questions.

I was wondering how long a charge on a battery will usually last? I have yet to get a fl day of flying since I am afraid of the battery dying on me.

What counts as a flight?

I tried to start my fairly new evolution 40 engine, But it kept hydro-locking. I had the fuel tank out of the plane and it was elevated, could this force access fuel into the engine?

Thanks, I am sure their are more to come.
Old 01-11-2010, 07:00 PM
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Default RE: Some Questions

NiCd or NiMH? A NiCd battery looses about 20% of it's charge in a month so a 4.8v receiver pack goes to 3.8v by the end of the month. A NiMH is supposed to discharge faster. - Why don't you just charge it before you fly?

What counts as a flight? - Anytime the wheels leave the ground. [sm=biggrin.gif]

And yes, the elevated tank is a smoking gun for your hydro-locking.
Old 01-11-2010, 07:28 PM
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Default RE: Some Questions

http://www.3epower.com/servlet/the-9...RC-NiMH/Detail buy one of those and will be able to put in at least 12 flights on your trainer .40 trianer


I use one on a 1.20 size yak with 5 digital and 1 std servo and can fly saturday and sunday at least 8 total flights(roughly 6-8 minute flights) and the battery is still good to go....
Old 01-11-2010, 08:04 PM
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Default RE: Some Questions

The tank being too high is the first clue to flooding. Most the people I know fly for about 10 minutes and call that a flight, some a bit more, some a bit less. You haven't said what type of pack, what voltage or what mAh the pack is. What type of servos and how many are in the plane? With a 4.8v 2400 mAh pack with five servos, I run both digital and analog depending on the plane, I get about 5 flights out of the pack on average, sometimes 6 sometimes only 4 depending on how I am flying the plane. I check my batteries before each flight with a volt meter and when they are getting close to there rated voltage then I use a field charger and top them back up. How long just depends on too many things to give a straight answer.
Old 01-11-2010, 08:45 PM
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Default RE: Some Questions

Well your going to get alot of different answers on here, flight times, battery charge life, it really helps to know what kinda plane you have, you did mention the engine, an evoloution, so I'm guessing it's a hanger 9 plane. if you feed us a little more we can pin-point any and every possibility that could cause your flooding issue, and give you a reasonable way to test your battery for life expectancy. Oh, and pic's help too if you can, especially the engine setup and plane.
Old 01-11-2010, 09:35 PM
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Default RE: Some Questions

If you are worried about the battery charge in the model when you are at the flying field you need one of these. [link=https://www.toysonics.com/hobbico-voltwatch2-4.8v-6v-rx-battery-monitor-hcap0332.html]CLICKY[/link]

It is called a Voltwatch and it gives you a good indication of the state of your battery under load. Lots of people will fit one permantly in the cockpit and look at it just before takeoff.
Old 01-11-2010, 09:58 PM
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Default RE: Some Questions

What size battery (mah) are you using? Is it a 4.8 or 6 volt? Nicad or NIMH?

How many servos? Are they standard, digital or high torque?

What transmitter are you using? Basic or computer radio? 72 or 2.4 ? What receiver?

This all helps if you want to know how long your batteries will last.
Old 01-11-2010, 10:37 PM
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Default RE: Some Questions

exactlly, if it's a spectrum system, don't let the receiver pack go below 4 volts, if it's a 72 MHZ system, 3.8 or even 3.6 volts is marginal for proper system operation(IE range and power consumption) as far as the motor and flooding, the low needle may be set too rich or even a combination of low and high needle being set too rich, causing the hydrolock condition.
Old 01-11-2010, 10:57 PM
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Default RE: Some Questions

My main plane is a Hangar-9 Pulse XT 60. It has a 1100 MAH NI-CAD Battery that I beleive is 4.8v. The servos are three JR DS537 and two other Jr servos (I cant remember what they are). What kind of voltmeter do I need, just a standard one? What is a no-go voltage?
Old 01-11-2010, 11:32 PM
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Default RE: Some Questions

if you have 12 bucks to spend on a battery(shipped) the answer is quite simple. get a 6v 2500mah battery from 3epower.com i wouldnt use 4.8v
Old 01-11-2010, 11:51 PM
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Default RE: Some Questions

Any volt meter is fine, and as someone mentioned, putting a Volt-Watch meter on the plane itself is a good investment, it will give you real-time readings of voltage, not actual numbers, but LED's that display from good to marginal on a scale. I know all about the tank hieght issues in a pluse, I had mine where it was hard to tune due to the hieght of the tank, but when it sit's on the ground, the tail is lower, and so is the tank being the fuselage is slanted downward. I would refer to the owners guide for the engine and verify the needle settings are correct before pointing to the tank being high, to hydrolock the engine it means that it's drawing too much fuel in the first place. As far as the servos, yes digital servos draw more power, but yours are mainly standard servos. Personally, I prefer std servos due to the power consumption, nothing I do requires high percision outputs on the control surfaces. So with that being said, as long as your battery on standard servos gets about 3 hours minimum runtime till it hits 3.8 volts, then your OK. but if after an hour you find the battery at that point, start thinking about replacing the pack with a new one. This is providing that there is no binding in the linkages or servos that are buzzing from being overloaded or bad potentiometers. There is always a reason why something is happening, it's up to you to put the pieces of the puzzle together and make sense of it all. I do this daily for work, I gather little tid-bits of customer information and piece together what happened to come to a conclusion of wat or where the problem is. Trust me, being a detective sometimes stinks, but the littlest thing can make a big difference, like someone not setting the needle correctly at the factory.
Old 01-12-2010, 09:00 AM
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Default RE: Some Questions

WARNING DO NOT FLY WITH A CELL VOLTAGE OF LESS THAN 1.1 VOLTS ON A NiMH PACK

Why look at the pic below. [ It is for a 2 cell pack ] A Nimh cell has a flat discharge curve untill near empty then it just falls off a cliff.

My Tx has 8 Nimh cells and will drop from 8.8 volts [alarm ] under load to 8.3 volts [Tx shut down] in less than 2 minutes under load.

Running a 4,8v 4 cell Nimh pack you should stop flying BEFORE you get to 4.4 volts and recharge. 4.6 volts is a reasonable figure to stop at.
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Old 01-12-2010, 10:02 AM
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Default RE: Some Questions

He said it's a standard 1100 mah ni-cad, at least we hope it is.
Old 12-19-2010, 10:27 PM
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Default RE: Some Questions

OK, time to make a zombie out of this dead thread lol.

I purchased a 4.8v , 2300 MAH 4 cell battery a while ago, this should last a little longer then the 1100 one right? Also, About the binding, my plane servoes usually makes little squeaking noises when just sitting their? Is this normal?

Also, Is 4 10 minute flight well in the safe zone? Like mantioned before, the set up is a Hangar-9 Pulse 60 with 3 JR DS-537 servos on the rudder, throttle and elevator and 2 JR DS-821 Servos on the ailerons. Battery is not a JR 4 cell 4.8v 2300 MaH.
Old 12-19-2010, 11:13 PM
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Default RE: Some Questions

Buy these and check your battery's BEFORE every flight. Dont fly if your battery pack is below 4.8v. You will figure out real quick how long your packs will last. $29 is a LOT cheaper than than replacing your plane. Everyone I know keeps an Expanded Scale Voltmeter in their flight box. Expanded Scale Voltmeters put a "load" on your battery so you can tell how it will react. A regular voltmeter only shows the standing voltage. A dead battery can show 4.8v, but under a slight load, will drop the voltage very fast down below 4v. This is a MUST have tool in my opinion.

http://www3.towerhobbies.com/cgi-bin...?&I=LXPWB2&P=M
http://www3.towerhobbies.com/cgi-bin...?&I=LXWW16&P=7


ORIGINAL: F-18

Also, About the binding, my plane servoes usually makes little squeaking noises when just sitting their? Is this normal?
Digital servos "chatter" when sitting at idle. This is normal.

ORIGINAL: F-18

I purchased a 4.8v , 2300 MAH 4 cell battery a while ago, this should last a little longer then the 1100 one right?Also, Is 4 10 minute flight well in the safe zone?
Yes, 2300 MaH should be fine for 7-8 flights maybe more, check between flights with the voltage meter as stated above.
Old 12-19-2010, 11:25 PM
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Default RE: Some Questions

OK, sweet, then I will defiantly pick up a voltmeter when I get some spare cash (student here, between my 3 very expensive hobbies their is not much to go around lol)

Just wondering, do I check the battery using the charging cord? Or do i Unplug the battery?
Old 12-19-2010, 11:40 PM
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Default RE: Some Questions

Buy one of these and put it in the side of your plane (opposite side of your exhaust) and just plug in to check your Rx pack voltage. Charge cord is fine.

http://www3.towerhobbies.com/cgi-bin...?&I=LXE962&P=0
Old 12-19-2010, 11:52 PM
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Default RE: Some Questions

Wait a min, did you say evolution 40 engine on a Pulse 60?? The Pulse 60 is a 7-8 lb plane. No way a Evo 40 is going to fly it worth a crap. Is this Punked? Are you ashton kutcher??

You should have an Evo 61 off your Alpha 60.
Old 12-20-2010, 12:31 AM
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Default RE: Some Questions

How long your battery lasts in flight and how long it last while left idle are two different things.

How long your battery lasts in flight depends on its mAh rating and rate of current draw. For a 50 size airplane, a 2000mAh should last atleast 5 flights after being fully charged. It will do more but its recommended to not try to squeeze out the last drop because you dont know what condition of charge the battery is in.

When left idle, NiCd loses charge with time. Again, how much charge is lost depends of degree of charge, mAh rating and condition of battery.

If you are concerned that your battery will get unusable due to not being used you are probably right. NiCd batteries are subject to a phenomena called "charge memory" in that a fully charged battery when left idle over time will "think" it is fully charged even when it has discharged. In this case it will show full voltage on a multimeter but will die out as soon as or shortly after being loaded. One way to get around this is to cycle your batteries during the off-season- charge to full and then discharge to minimum voltage recommended by the manufacturer. Many chargers can do this automatically for you but you can also do it by connecting the battery to your model and wiggling the sticks on your RX till it stops moving. Some TXs have a servo test feature that also serves to discharge and test your batteries. Most chargers will show a summary giving discharge capacity of a battery which should match the rated mAh otherwise the battery are on the way out. Some old batteries will "return" when cycled. Usually I dont such batteries

With respect to the tank, you should get a hydrolock if your engine is inverted with the tank position you described. If it is upright, the carb will simply overflow

Ameyam
Old 12-20-2010, 12:32 AM
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Default RE: Some Questions

Sorry lol, I have a Evo NX 61 in the Pulse, the Evo 40 is for a 40 trainer I have too lol.
Old 12-20-2010, 09:13 AM
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Default RE: Some Questions

This is a great battery checker for NiMh and LiPo batteries!!!

http://www.dynamiterc.com/Products/D...ProdID=DYN4062

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