lost my glider

[Freddy Bear]

I managed to loose my glider to a hungry sea the other day. I think the receiver stopped listening to my commands (battery died) I was on the third flight, about three minutes in, on a five-minute engine run, at about five hundred feet. Not a good place to be free flying with a RC glider. I jumped in the car and headed off in hot pursuit.
The engine had died but it was gliding in a large circle over a large expanse of salt water. It was then I thought that was the last I’ll see of that. This had not been a good morning.
In the afternoon about four o’clock I received a phone call “have you lost a glider” I was delighted. A chap named Glen had been driving along and spotted the plane in the shallows from a bridge. He took the glider home and washed out the sand and salt water in his bath. We arranged a meeting place and after handing him a reward a chat and hand shake we parted company. The glider was home again with very little damage before the sun had set. :) After cleaning and drying the receiver and connecting it up, all was working fine. :)

I’m working on trying to see if my receiver can operate on six-volts.


Maybe someone will know, or be able to put me in touch with someone who does. [/

The RX is a

CHALLENGER 720
DBM & X-TAL FILTER
HP-7RM36F
FM
Duel Conversion Narrow Band Receiver.
Will this run on six-volts?

If you have some info could you please PM me
TX
I run a FIELD FORCE 7 FUTABA
FP-T7UAPS
PCM-PPM SELECTABLE
[IMG]

The :) Reason I wanted to get the six-volt pack was to give me a greater margin of battery safety for high altitude.
I know from experience that it is not good to fly on low batteries but it is difficult to predetermine capacity with nicads because of the sudden drop at the end of their life.
When the batteries were new (and even then you might get a dud) you had some idea of their longevity.
On some days I would fly for Four hours driving seven servos and still have plenty over at the end of the day.
The batteries I used were old ones but I have a discharger that told me the batteries were good.
Maybe time to get a better discharger one with an amp meter built in or something.
The other thing I thought of was to double up that way if one pack drops the other would take over.
A little extra to carry will only speed the glider a little :) :)

[DFW_HLG_TG]

I was looking into using a 5 cell pack awhile back. From what I understand it will use more current and you have to watch the battery just as close. Are you using 1 or 2 packs? I would try to have a separtate pack on the radio gear. Also, If the pack is new, you will need tho cycle it a few times before it will reach 100%. I have had new battries put out only 30% the first time charged.

[MTT]

Why do you want to use a 6V pack ?
5 cell ( 6V ) packs are used on very large models, where the voltage drop along long servo leads could be an issue, and by folks who fly aerobatics, and want very quick and crisp response.

For you plane ( looks to me like something in the 2-3m span range ) a 5cell pack would be absolute overkill.

Anyway, the way I understand it, you want ot go to the 5cell pack for increased capacity ?
You don't need 5 cells, just buy a new good quality 4 cell pack, and you will be fine.

Michael

[MikeBanyai]

WalMart has rechargeable 2500 MAh NMH for about 10 bucks for 4 if I recall right. You can make up a pack and never be in the drink again due to batteries. This assumes of course that you have a way to charge and moniter them. The typical wall charger that comes with your radio only puts out 60 milliamps so will take 2400/60= 40 hrs to charge and even then may not do the job compleatly. Hobbico has a fifty buck field charger that can charge radio and reciever batts at the same time...good luck

[SoCalGliderFlyr]

They have WalMarts in Tasmania?

Fred, Where do you buy from? Mail order?

[MikeBanyai]

Sorry, I didn't catch the Tasmania reference, The concept of useing 2400 MAH NmH vs 600 MAh NiCAds still applies...warmest regards,

[SoCalGliderFlyr]

I like the 2400's too. On my way to Walmart this afternoon! Hope this doesn't upset Fred. Maybe we can send him RC Care Packages!!!

What do I charge them with? Time and rate?

[Freddy Bear]

They have WalMarts in Tasmania?

Fred, Where do you buy from? Mail order?
I usually buy locally at a place that has a larger turn over of stock but this doesn’t mean that you buy quality. Maybe I need to get some sanyo.
But budget dictates what is used. :)
[IMG]

[FLYRCM]

Our club used to fly in Hong Kong right next to the harbour. From time to time, someone's aeroplane lost control and ditched into the harbour (salt water) . The first thing we did when we picked up the plane was to disconnect the battery & dumped the whole radio into fresh water. We rinsed it a few time and let it sit dry.

The crucial part is to disconnet the battery ASAP or in your case, no more power running through the electroncis. The power in the battery will corrode the electonics component away. Just like the electrolysis experiment you done in science project at school.

Dumping the whole airborne unit in fresh water will save the unit most of the time unless the unit has been sitting in salt water with power to it for a prolong period of time.

[2motheus]

Our club used to fly in Hong Kong right next to the harbour. From time to time, someone's aeroplane lost control and ditched into the harbour (salt water) . The first thing we did when we picked up the plane was to disconnect the battery & dumped the whole radio into fresh water. We rinsed it a few time and let it sit dry.

The crucial part is to disconnet the battery ASAP or in your case, no more power running through the electroncis. The power in the battery will corrode the electonics component away. Just like the electrolysis experiment you done in science project at school.

Dumping the whole airborne unit in fresh water will save the unit most of the time unless the unit has been sitting in salt water with power to it for a prolong period of time.

I've also heard that dunking things in alcohol helps get water out. But I'm not sure what that might do to the light lubricants in the servo mechanics.

[Freddy Bear]

I've also heard that dunking things in alcohol helps get water out. But I'm not sure what that might do to the light lubricants in the servo mechanics.


:) The water didn't get into the servos I think the lubricant kept the water out. :) ;)

[Freddy Bear]

I like the 2400's too. On my way to Walmart this afternoon! Hope this doesn't upset Fred. Maybe we can send him RC Care Packages!!!

What do I charge them with? Time and rate?
HI Socialgliderflyr, :)

The charger I have tells me nothing except RED LIGHT ON when charging. I do my tests with a multitester and a discharger I built. When the batteries drop there voltage a relay drops out and charging begins.
I am also doing some tests with a square wave driver at twelve volts. This has a pot to lengthen or shorten the DC pulse at 50Hz. ;)
I have found that you can rejuvenate nicads and get them working again. :cool:

[Freddy Bear]

Why do you want to use a 6V pack ?
5 cell ( 6V ) packs are used on very large models, where the voltage drop along long servo leads could be an issue, and by folks who fly aerobatics, and want very quick and crisp response.

For you plane ( looks to me like something in the 2-3m span range ) a 5cell pack would be absolute overkill.

Anyway, the way I understand it, you want ot go to the 5cell pack for increased capacity ?
You don't need 5 cells, just buy a new good quality 4 cell pack, and you will be fine.

Michael

Thanks Michael,
I know it is probably too much putting a five-cell pack in the glider so I’ll get a new set of Nicads.
??? What is the advantage of Ni-MH over Nicads and what is the best way to charge both in the field.
I go camping and there is no power to use the standard charger.
My son has a fast nicads charger for his cars with a timer and I have an identical charger that I could alter. Would this charger be any good to charge Ni-MH with a small modification???? :)

[MTT]

??? What is the advantage of Ni-MH over Nicads and what is the best way to charge both in the field.
I go camping and there is no power to use the standard charger.
My son has a fast nicads charger for his cars with a timer and I have an identical charger that I could alter. Would this charger be any good to charge Ni-MH with a small modification????
I don't know enough about chargers and the different types of batteries to answer those questions.

For charging in the field, there are lots of chargers available, which run off a 12V car battery, and do a good job.
For my NiCd's I use a FMA direct SuperNova ==> SuperNova (http://www.rcbatteryclinic.com/nova.htm) , and an Astroflight 110D ==> Astroflight 110D (http://www.astroflight.com/e/env/0001l9UmOTIeaKouSc22657/store/store-Chargers.html?link=/store/store-type-tem.html&item=products:af-110).
For my LiPo's I use a Schulze isl 6-330d ==> Schulze 6-330d (http://www.rc-direct.com/schulze330.htm)

All of these run on 12 V DC , to use them at home n the shop, you will need a 12 V power supply, or a car battery, but then that's another battery to worry about... :)

Michael

[histarter]

Ugh, Raise voltage with 5 cells and circulating current increases! This translates to reducing run time. [Wrong way to go]

Primative.

[Daniel G]

??? What is the advantage of Ni-MH over Nicads and what is the best way to charge both in the field.
Nimh are less weight for the same capacity. So you can have a 2000mah nimh that is about the same weight as a 700mah nicad. Nimh can't handle as high a charge rate as nicads though, as they should be charged at 1 x capacity or less.

[MTT]

Ugh, Raise voltage with 5 cells and circulating current increases! This translates to reducing run time. [Wrong way to go]

Primative.


Before slamming other users like this, maybe you should learn how to spell...
Primative ???????????

[histarter]

Before slamming other users like this, maybe you should learn how to spell...
Primative ???????????
No slam intended. We have gotten so sophisticated we tend to overlook basics. Even my technicians have gotten so sophisticated that they cannot write a program to operate a rattrap in BASIC; to run on a 486! HI

As a 'handle' we have certain liberties [I thought?] Prime for primary, tive for active application. :rolleyes:

Histarter
(or should I write 'high start launcher' to be within zero tolerance) HI :)

HI = LOL, a carry over from Morse code. (yes, I am ancient)

[paulcarnes]

HI = LOL, a carry over from Morse code. (yes, I am ancient)

dit dit

-.- -.-. ..... .-. --. --.-

[paulcarnes]

One thing I find really interesting about NiMh is their life. I have one AAA pack that is four years old and still tests in the 700's. Pack is made up from batteries off the shelf at Wal Mart and a holder from one of my HiTech radios.
I have a couple of lipo's but you usually want some nose weight and I hate to add lead where the battery could be.

Paul

[BMatthews]

I know I'm getting in on this late but I agree with what the others are suggesting in that what you need is more capacity and not higher voltage. If you are using nose weight to set up the right balance then trade the nose weight for as large a battery pack as you can fit in there. If 4 sub C cells will fit then that's the way to go.

If you're doing a lot of charging from 12v then you want to either get a peak detector charger or monitor the charge closely with a digital voltmeter. As mentioned NiMH cells really should only be charged at 1C to 2C and at that rate you really need to watch for the peak or risk damaging them with an overcharge. Or just as bad, not put enough charge into them and find your model flying away again. For this level of monitoring the timer controlled chargers just are not worth it. If the two of you are running lots of packs then invest in a charger that'l do it all and do it right. That means variable charge rate and peak detection.

[Freddy Bear]

I know I'm getting in on this late but I agree with what the others are suggesting in that what you need is more capacity and not higher voltage. If you are using nose weight to set up the right balance then trade the nose weight for as large a battery pack as you can fit in there. If 4 sub C cells will fit then that's the way to go.

If you're doing a lot of charging from 12v then you want to either get a peak detector charger or monitor the charge closely with a digital voltmeter. As mentioned NiMH cells really should only be charged at 1C to 2C and at that rate you really need to watch for the peak or risk damaging them with an overcharge. Or just as bad, not put enough charge into them and find your model flying away again. For this level of monitoring the timer controlled chargers just are not worth it. If the two of you are running lots of packs then invest in a charger that'l do it all and do it right. That means variable charge rate and peak detection.
:) :) Thanks I think I will go for the electronic charger with NiMH cells. just have to save my pennies. :) :)