Where do you buy twisted wire servo extensions?

Not sure about the USA but in teh UK SM services would make them to order.

Paul

I just got a bunch from Troy Built Models. They are sold in pairs and two 48" ones were only $9.98.
Here is the link right to them

http://troybuiltmodels.com/ServoExt.htm

Check Airwild Hobbies, bought a whole bunch of them for my SM F-15.
Their E-mail is [[email protected]].
Have bough several items from them on different occassions, good prices & service.

Buy the wire from an electronics store like Newark Electronics and twist it yourself. I made a hook and put in my drill, attach the three wires to it, hold them with one hand and run the drill with the other. You have to put your own ends on though!!

If you already have factory extensions you can convert them. Just split the leads, put one end in a drill and hold the other end. Spin it to a tight twist, it will relax after you release the end. It will hold a twist very well.

I used these on my Baby Boomerang and the crimping failed on one of the leads during assembly for the second flying session. I gently pulled the plugs on a few other leads and some of these also failed. I called SM services and they indicated this is a rare occurrence and asked me to send all the leads back (approx. 12 in the model) and they replaced them all. I am now concerned about the leads and check them thoroughly before every flight and will probably change them for some JR leads over the winter just to remove any worry. (Note these were the heavy-duty silicon twisted extension leads)

Troy Built has some of the best deals on the twisted lead ones. You get two leads for a tad more then you would pay for one. They are twisted, use heavy gauge wire, and they use a universal male connector on one end, and the female end is for futaba. That way, if you have futaba servos like I do, but fly JR you can connect them together without having to shave the little tap that is on futaba connectors.

They have great service as well.

Peak Electronics here in the US. They sell the wire and ends to make your own custom lengths.

Thanks for the input guys, I do not want to make them myself. I either want to pay for custom length or find pre made lengths that will work for my application. The longest I will need is 42" so I should be able to purchase pre made ones fairly easily.

Hitec makes them 6" 12" 24" 36"
try:
www.hobbyhorse.com
www.servocity.com

Im curious. Why do you want or need them twisted ? Whats wrong with standard JR/Futaba type non twisted extensions ?

WWW.Ashtekelectronics.com. This guy will make up any extentions to your spec, or sell you the kit to make your own. His site is well worth a look. Ray.

In short "Noise cancellation"

From a goggle search...

Twisted-Pair Cable

Twisted-pair cable is a type of cabling that is used for telephone communications and most modern Ethernet networks. A pair of wires forms a circuit that can transmit data. The pairs are twisted to provide protection against crosstalk, the noise generated by adjacent pairs. When electrical current flows through a wire, it creates a small, circular magnetic field around the wire. When two wires in an electrical circuit are placed close together, their magnetic fields are the exact opposite of each other. Thus, the two magnetic fields cancel each other out. They also cancel out any outside magnetic fields. Twisting the wires can enhance this cancellation effect. Using cancellation together with twisting the wires, cable designers can effectively provide self-shielding for wire pairs within the network media.

This explain why. I'm using 18ga servo extensions twisted 60" long into the booms of my boomerang Xl with no filter. 50 + fligth not a single glicth. Text copy from TBM.


Note on twisted extensions: If you are still using 72 or 50 MHz transmitters instead of the new 2.4 GHz or Spread Spektrum technology, twisted wires are suggested. If you are using the new technology, twisted wires offer no advantage to untwisted wires. Twisting extensions eliminates interference caused by stray signals being picked up by the signal wire in the old MHz systems. The wire can act like an antenna. This is rarely a problem, but if you have an intermittent interference problem this may be the cause. The signal wire (usually orange or white in color) has little current running through it. It tells the servo what position it needs to be at. The red and black wires have higher current in them as they provide power to the servo. Only the signal wire will pick up stray signals due to the low current. Twisting the wires in effect wraps the signal wire around the power wires which cancels out electrical noise. The noise is called electro-magnetic interference, abbreviated to "EMI". Typically extensions which are around 3' long cause more problems because they are the length of a receiver antenna, but extensions of any length near a gasoline (spark) engine ignition system can pick up EMI from the engine's ignition. DA, 3W, ZDZ, and other ignitions are now shielded so well that this is rarely a problem. Also, resistor sparkplugs are used which keep EMI down. For these reasons, we offer only twisted wires.

Alejandro

Just a word of caution when twisting extention cables. Twisting can put a lot of strain on the end of the wire where it is crimped or soldered to the pin. I was involved in twisting thousands of cable from 1968-1983. We used a tool that clamped down on each wire just where it exited the connector shell so the strain was not applied to the connection to the pin or socket.

In my opinion a lot of the problems associated with long leads is caused by the fast rise time of the pulse produced by the decoder IC. We used a .001uf cap from each signal lead to ground in our receiver to roll off the rise time a bit on the radios we built. I know the .001 cap reduced the trash on the signal going to the servo. I have run servos over cables as long as 150 ft.

Twisting the leads adds capacity between the signal lead and ground. One disavantage to twisted cable is the larger amount of resistance for a given length of cable which will cause a larger voltage drop to the servo.

In a model I am building I plan to use an 18 gage twisted power buss from the batteries in the nose to the servos in the tail which are about 80 in. apart. I will also run a 26 gage ground wire twisted with the 26 gage signal lead for each servo.

Thanks for you 2 cents sidgates. But now where we can find the 18ga servo extensions. They are now very hard to find. The guy I bouth them from is out of buissnes, he still have some stuff on e-bay but not this ga servo extension. Plus the correct gold plate silicone wire I can not find in the Radio Shack in my area. I will need more 18ga for my next projet. Thanks.

BTW: I twisted mine by hand to not strengh th ecables too much. I know about the resistance and voltage drop. Can you explani me better how to solve this. In order to have better life of my batts. I haven't use those units like Power boxes, or expanders.

Rgs
Alex

Just buy 18 guage wire, twist three strands to the length required, then take a short aileron extension, cut it in two and solder it to the ends of the twisted length. Viola!

Works for me. I let the pros do the connectors and I take care of the wire in between. And if it doesn't have to be disconnected, I just make the servo lead as long as needed.

Yes I know how to make the extension. And I also like your idea about the conectors. I know that there is a voltage drop in long extension specialy when we twisted then cause we are making a resistor doing this. The only cure I figure out to help is using big gage wires. But there is another option? That's what I'm refering.

Alex

Has any benefit been proven on small rc installations ? I mean, same installation, install twisted cables, make a range check with antenna retracted until signal degradation, then swap them with not twisted ones and see if it makes a difference. It might be another urban legend. Very long straight extensions are on sale everywhere so ...