Espritmodel.com Telemetry Radio
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Old Nov 03, 2005, 03:43 AM
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Freddy Bear's Avatar
Hobart Tasmania
Joined Aug 2005
60 Posts
Help!
lost my glider

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
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Last edited by Freddy Bear; Nov 06, 2005 at 03:40 AM.
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Old Nov 03, 2005, 07:24 AM
DrCarter
Princeton, TX
Joined Jan 2005
638 Posts
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.
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Old Nov 03, 2005, 07:39 AM
MTT
I care about rising air !
MTT's Avatar
West Chester, Ohio
Joined Feb 2002
2,004 Posts
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
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Old Nov 03, 2005, 09:51 AM
Registered User
Petoskey, Michigan 49770
Joined Aug 2001
66 Posts
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
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Old Nov 03, 2005, 09:57 AM
Think Thermals!!!!
SoCalGliderFlyr's Avatar
Costa Mesa, California
Joined Mar 2004
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They have WalMarts in Tasmania?

Fred, Where do you buy from? Mail order?
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Old Nov 03, 2005, 10:11 AM
Registered User
Petoskey, Michigan 49770
Joined Aug 2001
66 Posts
Sorry, I didn't catch the Tasmania reference, The concept of useing 2400 MAH NmH vs 600 MAh NiCAds still applies...warmest regards,
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Old Nov 03, 2005, 11:04 AM
Think Thermals!!!!
SoCalGliderFlyr's Avatar
Costa Mesa, California
Joined Mar 2004
2,964 Posts
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?
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Old Nov 03, 2005, 07:51 PM
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Freddy Bear's Avatar
Hobart Tasmania
Joined Aug 2005
60 Posts
Quote:
Originally Posted by SoCalGliderFlyr
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][IMG][/IMG]
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Old Nov 04, 2005, 08:08 AM
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Joined Oct 2005
24 Posts
Radio ditch into the sea

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.
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Old Nov 04, 2005, 09:04 AM
3 Sons - Legos and Lift
2motheus's Avatar
Grand Rapids, MI
Joined Apr 2004
558 Posts
Quote:
Originally Posted by 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.
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.
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Old Nov 05, 2005, 06:00 AM
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Freddy Bear's Avatar
Hobart Tasmania
Joined Aug 2005
60 Posts
Quote:
Originally Posted by 2motheus
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.
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Old Nov 05, 2005, 09:42 PM
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Freddy Bear's Avatar
Hobart Tasmania
Joined Aug 2005
60 Posts
What do I charge them with?

Quote:
Originally Posted by 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?
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.
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Old Nov 10, 2005, 04:32 AM
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Freddy Bear's Avatar
Hobart Tasmania
Joined Aug 2005
60 Posts
Quote:
Originally Posted by 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
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????
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Last edited by Freddy Bear; Nov 10, 2005 at 04:39 AM.
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Old Nov 10, 2005, 07:28 AM
MTT
I care about rising air !
MTT's Avatar
West Chester, Ohio
Joined Feb 2002
2,004 Posts
Quote:
??? 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 , and an Astroflight 110D ==> Astroflight 110D.
For my LiPo's I use a Schulze isl 6-330d ==> Schulze 6-330d

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
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Old Nov 16, 2005, 09:54 PM
Permanently Banned
Dallas TX
Joined Oct 2004
1,551 Posts
Ugh, Raise voltage with 5 cells and circulating current increases! This translates to reducing run time. [Wrong way to go]

Primative.
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