Hello,

I have a small doubt , i am really new to this radio stuff and i didnt ever handle them .What is the difference between the cables connecting the reciever and the servos i.i the ( three wire grouped ) and the cables wich are normally used in computer hardware ie printer port cables etcc.. they too have the look and appearance, and same wiring color too.

Two totally diferent things:

SERVO:
- white or yellow is signal
- black is negative
- red is posistive

Now on a computer you are using a bunch of wires, usb, firewire, pararell, serial, serial ata, ribbons cables(diferent kinds), and so on, so if you are trying to related send, receive and ground with the servo wires good luck.

The thing you have to watch out for on servos is voltage drop. You must use very good connectors and use adequate size wire. If your runs are more than a foot, use at least 22 gauge wire. A servo can draw in excess of 2 amperes for a few microseconds at each command or if it gets stalled by stiff linkage or excessive air loads. This will be evidenced by servo jitter if not complete loss of control. If possible, do not use extensions, solder on longer leads instead.

I would make sure that the strand count is high enough to not cause failure from vibration.

Thanks for your information guys.

Hey, i was thinkin of using 3 port computer cables to extend the servo wires and without your caution ...................


Anyways, then how are u going to connect the servos to control surfaces if your plane long and wide, do you use direct linkages from the servo obviously placing at proximity to reciever and battery , or do u extend it. Becoz my plane would be 5 ft long and 9 ft wing spans , is'nt that interesting.

As was mentioned, you can use servo extensions of almost any length. Of course the longer the wire, the more resistance you'll have.

Rodney's advice to solder longer leads directly to the servos is a good one, especially for extensions over about 12 inches max. With extensions you also add connectors, and connectors are another source of resistance. For extensions of 12 inches and under I wouldn't worry about it. (You should consider a larger battery pack that the original though.)
Dennis-

Hello guys ,

After i had a thorough reading of your replies later again , i am seriously in a position whether i got the correct concept imprinted . I ll let u know correctly of what picture i have in my mind.

What is this 'extension' referred to .

What is this 'lead' referred to. And how is soldering process linked to it and how u do that.

As to my knowledge, whatever extra length for connector the designer is providing from the default connector pin to the actual position of servo. is extension. Do u mean the 'direct connector' without any pins in between is called as lead !?

I know that as u increase the length of wire ; resistance automatically increases for that connector or cable. Does this have a considerable effect on the servo movement , ya ,even though torque is directly linked to the current supply from battery. Now will there be any time- lag which might hinder the response time to control the aircraft. With such long 2-3 ft extensions , do any kind of interferences exist in flight.

??? What is this " 22 guage wire " , Is this the classification of any normal electric wire or related to any dimension of the wire.

OK at this juncture , i would like to ask u one final thing;

How do u classify these 4-wire pin to pin connectors used in ur PC or any computer, even though they have the same universal
red +ve
balck -ve and other wire for signal.
Signal here refers to ' nothing but current ' whether its micro or milli, etc;

if resitance is low enough , Is there is any reason that the actual servo wires cannot be replaced here with such computer cables.
Is there any big difference between the strand count in wire or cable for the one which is given with radio control set { like aileron extension cables, heavy duty cables etc.. }and the one which is used in computer cables.


Please dont mind ; i am seriously young to this eletronic part, bcoz i am doing my engineering in aeronautical.

With the questions you are asking, I would seriously suggest not making your own cables. Get help from someone close. You can put the servos closer to the control surfaces, and get 2 to 3 foot extentions pre made from tower or ebay made for your radio. You start messing with computer cables and making your own, and you could have an out of control plane going who knows where fairly fast.

What plane are you building? What kind of push rods are you running from the servo to the surfaces? You can make longer push rods so the wires don't have to be long from the receiver to the servo.

Does this plane have plans? Where do they put the servos in the directions?

Hi Radil,

Its not that hard to make up your own cables/wires.. You just need the connectors
etc. to fit servos etc.. Make sure the gauge is right, and make them as short as
you can.. And make sure ALL CONNECTIONS ARE TOP NOTCH.. Otherwise the
little money you save... WILL COST YOU MORE!!!

Really extensions or what ever you need that's already made up is not that much
more just to order or get at your LHS.. Your choice.. But most likely the connectors
will need to be bought.. Not unless you have the type and or make up your own..
That is IF you already have all that you need to make your own.. Don't mix up the
connection.. They do fry fast.. But it's not really hard, As long as you follow some
simple wiring rules... But really its hard to beat just ordering what you need!!

Just so we're clear.

The "Lead" is the wire attached to the "servo". The "Extension" is the addition to the "Lead". The "Connectors" are the "plugs" at the ends of the wiring.

The best thing to do when using long "Extensions" is to eliminate the two "connectors" in the middle, and solder the wires together because those connectors will cause additional resistance. You should use wire of the same "gauge" (same size wire) or slightly larger), and with the same number of "strands" to avoid problems.

(If you're really good at soldering, remove the "lead" from the servo and solder on a longer one.)

Hope this helps clear things up.
Dennis-

Thanks guys,

Atlast i got it . Thanks for ur picture.
So if there is good connector which can suit the servo it wont be any problem , reducing the extensions would definitely be better.

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