l.wilber

My Feedback: (3)

I'm having some problems with a model I recently completed and the subject of servo extentions came up. Does anyone factually know how long servo extentions can be and if they get too long how to remedy this. I've heard not to pass 9 inches but the manufacturer sells 24 inch extentions. Did I miss an important memo??? Anyway I haven't ever had this problem most of the models I've built used push rods. I don't like control issues while in flight this makes messy airplanes and oh yeah dangerous. If you have ever had interference issues due to servo extentions please let me know what to do. Thanx

Campy

My Feedback: (1)

Basically, if you are going have a servo wire AND lead go over 12" from the receiver, you want to use the heavy duty servo leads. They are a heavier guage of wire, so you don't have the losses as you would in the thinner wire.

I frequently use 18" and 24" servo extentions with absolutely no problems, BUT, they are the HD leads.

FWIW - I also wrap a piece of tape around the connector as a safety precaution against them becoming separated.

TLH101

My Feedback: (90)

If you use good quality extensions, you can go up to 3' or more without any problems. Too small wire can cause a voltage drop, but with better brands of extensions, thats not a real problem.

voyager_663rd

and if you splice your own wire (ie 20) in between the original servo/connector, you can be the judge as to whether it's hd or not.

paladin

My Feedback: (9)

Wilber, what is the problem you are having?

platero

If you have interference it is not due to the voltage drop, to me is bacause the long wires acts like antennas. Try cut the servo wire and make it more long with stereo mic. cable, this come with an external mesh, this must to be soldered to the black cable. I use this method for years in my big planes (1/3 Extra 300 3W 140 by example) with out problems. Good luck

Rodney

I have to dissagree with Platero. As an electrical engineer and some 50 years in the hobby, voltage drop is the prime cause of the problems, especially in the connectors themselves. If you have hidden connectors (those not repeatedly dissconnected and reconnected) make sure they are very good ones else corrosion over time will cause problems. If you are using high current servos, the size of the wire is very important, especially in the ground side as any voltage drop in that leads subtracts from the magnitude of the voltage on the control line. I have never had a problem with any part of the wiring acting as an antenna. Of course you all know that the wiring in any RC setup is part of the ground plane (the other half of the antenna system).

jimcork1

My Feedback: (4)

I have gone up to 5' on my multi engine,, but I use 22 gauge wire, twisted with a drill and solder connections. The only plug in is at the wing installation and receiver. This is for a "standard" 40 oz servo. If the servo were a high per. or aerobatic bird with 100 + oz servo I would consider 18 gauge.. Just My Opinion on the bigger servo.

.. Jim

platero

Ok Rodney nice your coment, in my experience low Volts in servos mean low velocity but no interference, most cases of interference i saw was because wires in pull pull systems, trottle metallic pushrods or low batery in the reciver...but y accept that each teacher with him book!!!

blikseme300

My Feedback: (118)

Rodney is correct in his observation. The one point he did not explain is that the voltage drop on the SIGNAL line can cause what appears to be interference. The amplifier portion of the servo will be affected by resistance and hence lower signal current. The frequencies in the servo leads and the antenna are very different. The filters in the RX will block the servo signal out. Only if the antenna and servo leads are in very close proximity is there an increase in chances of xtalk. Just keep them seperate.

Safe Flying!

SamD

If you're handy with a soldering iron and are comfortable opening up a servo, skip the extensions altogether. Open up the servo, unsolder the existing lead and solder in a new lead (or length of servo wire) the needed length and you've eliminated an extra connection and point of voltage drop. Obviously, if using servo wire you'll have to have a crimper and the proper connectors to attach to the wire. You'll want to use the appropriate gauge (heavy duty, probably) depending on the total length of the lead.