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-   -   Why is it so hard to make servo extensions? (https://www.rcuniverse.com/forum/questions-answers-154/5245005-why-so-hard-make-servo-extensions.html)

jzinckgra 01-10-2007 08:42 PM

Why is it so hard to make servo extensions?
 
So I thought I would smarten up and save some $$$ by making my own servo extensions. Paying $6 for a 12" extension is crazy, so I thought. So I bought 50ft of Hitec 22G wire and some male/female plastic clips and connectors. I spent a half hour trying to make one and didn't succeed. I tried using needle nose pliers to crimp the connectors, but you have to get it just right or the wire will slip or the connector won't fit easily into the plastic fitting[:@] Is there something I am missing here? I don't feel like crashing my new plane to save a few bucks, but I am willing to give it another go if there is a trick to doing this.

acam37 01-10-2007 08:57 PM

RE: Why is it so hard to make servo extensions?
 
One thing you can do is cut the servo wire and splice in your extension wire to the desired length. I do this on all my planes and feel it is more reliable than trusting extension plugs. (they can sometimes vibrate loose or not make good contact.) I solder the wires and use heat shrink tubing which makes a permanent and failproof connection.

pkoury 01-10-2007 09:00 PM

RE: Why is it so hard to make servo extensions?
 
Needle nose pliers are not the tool to use to crimp the terminals on the wire. Buy the correct crimp tool, I use the MOLEX universal crimper but you can buy a terminal crimper that will work at Radio Shack. The crimpers have a special design that makes the crimp very secure.

Hurri 01-10-2007 09:01 PM

RE: Why is it so hard to make servo extensions?
 
Easiest way for you is to cut the servo wire in the middle point & splice in a piece of wire to get the length you want . Make sure you do a GOOD solder job on the 3 wires , use shrink tube over each wire & a single larger tube over the 3 together . I do that if i need to get out to the servos in wings , if it is too long I use shielded cable in the same fashion . To make your own plug ends as per radio , hopeless .

rc-sport 01-10-2007 09:28 PM

RE: Why is it so hard to make servo extensions?
 
That's what I do, it's better then shelling out cash for extensions

jzinckgra 01-10-2007 09:39 PM

RE: Why is it so hard to make servo extensions?
 
Ok, great. I didn't think about splicing the wire. BUt just so I don't screw up my $75/servo, after you cut the wire and get ready to solder, do you just lay the two cut ends side by side then solder or do you twist them together first, then solder? Also, what's the best solder for this purpose? thanks

Don M. 01-10-2007 11:07 PM

RE: Why is it so hard to make servo extensions?
 
I bought all the gear to make my own extensions including a good crimper. Try as I may I could not get the hang of it [:@] after hours of trying and all kinds of ruined stuff. I'll put the remaining stuff on e - bay some day. In the mean time I spend the extra bucks and let someone else do it :eek:

Live Wire 01-10-2007 11:31 PM

RE: Why is it so hard to make servo extensions?
 
Don
Well it gets interesting but people make some things harder than the are ! YOU JUST HAVE TO FOLLOW INSTRUCTIONS and use your head and every thing will come out right. Not every one is an Elec. Eng. so don't feel bad if you had a problem [:@] Common sence and good practice is the best way to go. Good solder connections are better than plug in's any day;)

DMcQuinn 01-11-2007 12:16 AM

RE: Why is it so hard to make servo extensions?
 
troy built sells a crimper that works well. I make all my own extensions now.

Rcpilot 01-11-2007 12:45 AM

RE: Why is it so hard to make servo extensions?
 
1 Attachment(s)

ORIGINAL: jzinckgra

Ok, great. I didn't think about splicing the wire. BUt just so I don't screw up my $75/servo, after you cut the wire and get ready to solder, do you just lay the two cut ends side by side then solder or do you twist them together first, then solder? Also, what's the best solder for this purpose? thanks
Strip about 1" on each wire. Open the wires up so they are spread out really well. Overlap them so that the wires are not too far and going past the insulation. Twist the wires around each other. Solder. Slide your heat shrink over the joint and use a Bic lighter to shrink. Shrink slow. Burned up servo wires suck.

Here are some pictures of how to solder servo wires together.

acam37 01-11-2007 01:10 AM

RE: Why is it so hard to make servo extensions?
 
Rcpilet gives you a good diagram for the wires. The key to a good solder joint is a clean solder gun tip and flux. the solder will wick into the two wires and will become a permanent joint. Be sure to seperate the three wires back a few inches and put your heat shrink tubing on the wire before you solder them together. have the heat shrink down the wire far enough so the heat from the solder does not shrink the tube before you slide it over the exposed solder joint. After all three are done then put a larger piece over all three and shrink it down. makes a very nice and professional splice. I got a roll of .050 rosin core solder and some rosin paste flux from Radio Shack a few years ago and I'm still using the same roll.


Kmot 01-11-2007 02:22 AM

RE: Why is it so hard to make servo extensions?
 
I tried the end making kit also. I have expensive pro crimpers. Still useless when it comes to servo plugs. They must make them on computer controlled robotics.

Anyway, I do the extension wire splicing thing too. But I wanted to make some comments. First, solder in and of itself is not mechanically strong. Wires that are layed on each other, or loosely twisted together will not be as strong as wires that are looped around each other. So what I do is strip the wire, twist it, then form it into a "U" shape. Each end is done like this then the two "U" ends are put together to form something like a figure 8 and then they are twisted together and soldered. Second, I space my cuts/splices apart. Stagger if you will. That way, it doesn't look like a Boa Constrictor after a fresh meal. You know, the big fat 'lump' in the middle of your wire run. By staggering them the wire run stays relatively slim.

MinnFlyer 01-11-2007 07:36 AM

RE: Why is it so hard to make servo extensions?
 
I do it exactly how Rcpilet says not to, however, I always "Tin" the ends first.

Here's a "How-To" I did a few years ago on soldering. The first section shows how to do servo wires:

http://www.rcuniverse.com/magazine/a...article_id=172

bkdavy 01-11-2007 07:52 AM

RE: Why is it so hard to make servo extensions?
 
A couple years ago, my wife gave me a Coleman coldheat soldering gun (I've seen them in the Grocery store!). Turns out to be a FANTASTIC tool, particularly for soldering wires together. No waiting for the iron to heat, no tinning of the tip, no cords to melt. I can solder servo leads together in a matter of 1-2 minutes start to finish. Just be careful not to break the Carbon Tip Electrode. I highly recommend this for the hobbyist thats only doing small, infrequent jobs. For board construction, I still like the traditional soldering iron.

Also remember for proper solder flow, heat the wire, not the solder, with the tool. Let the solder flow when the wire is hot enough. Remove the solder, then remove the gun, and allow the joint to cool before pulling.

Good Luck!

Brad

jzinckgra 01-11-2007 08:47 AM

RE: Why is it so hard to make servo extensions?
 

Also remember for proper solder flow, heat the wire, not the solder, with the tool. Let the solder flow when the wire is hot enough. Remove the solder, then remove the gun, and allow the joint to cool before pulling.

Thanks guys for all the suggestions. I have tried what Brad says above, but on most solder jobs, I can never get whatever I am soldering hot enough with the soldering gun alone, prior to melting the solder to the surface. I have two guns: a weller for larger jobs and a small plug-in for electronics. I usually end up just using a little flux, then heat the surface with my small butane torch, then apply the solder. Is this a good idea on small servo wires though?

MinnFlyer 01-11-2007 08:52 AM

RE: Why is it so hard to make servo extensions?
 
For a small job like a servo wire, it is not practical to get the wire hot first. Just flux the wire, add solder to the tip of the iron, and touch the wire to the tip of the iron. Now the wire is "Tinned".

Place two tinned wires side-by-side, and again, touch them to the tip of the iron.

The solder that is already on them is usually enough to join them. Additional solder is rarely needed.

bkdavy 01-11-2007 09:45 AM

RE: Why is it so hard to make servo extensions?
 
For soldering wires and small connections, the key is to put the heat source on one side of the wire. Apply heat for 1-3 seconds, then touch the solder to the opposite side. The solder will quickly flow through the wire bundle toward the heat source. Remove the solder wire, remove the heat source. Any more that 3-5 seconds is wasted time.

Brad

JPMacG 01-11-2007 12:57 PM

RE: Why is it so hard to make servo extensions?
 
www.radicalrc.com sells a crimper that works well for me. You need to read the instructions carefully and orient the connector properly in the jaws of the crimper. Also, a magnifying work light is a big help. Take one or two practice crimps on some scrap wire first.

I do agree that a soldered connection is always better than a connector pair. Use small diameter electronic grade solder, not the stuff that plumbers use. Cleanliness is the secret to soldering. If the parts are dirty or corroded you will not get a good joint. The soldered joint should be shiny and smooth after it cools. A 20 watt pencil works well for me. I think a gun would bee too big and too powerful for servo wires.

Tall Paul 01-11-2007 01:56 PM

RE: Why is it so hard to make servo extensions?
 
I always splice.. the connectors I've tried to work with never keep the pins in properly.
Rcpilot's method... but only about a 1/4" of wire exposed on each lead..

Hurri 01-11-2007 02:21 PM

RE: Why is it so hard to make servo extensions?
 
To recap what i said earlier . rc pilot has a very elaborate idea for soldering the ends of wires together , in his sketches he has a big cross thru the way i do it . I have been soldering wires that way for donkeys years . Never ever had a bad connection or come apart . I always cut the ends back about 3/16" , twist each seperate wire so no ends loose . I have a small tin of resin core flux by my pencil type soldering iron , dip the end of wire in flux & then tin the ends of wires . now lay side by side the 2 ends & solder . one has a piece of shrink tube already on one end of wire before soldering of course. Then to shrink the shrink tube I use a heat gun , Used to use the top end of the soldering pencil .

Rcpilot 01-11-2007 04:38 PM

RE: Why is it so hard to make servo extensions?
 
I just don't like soldeirng the wires together for asthetic reasons. My way ends up a little thinner when your all done. So, I didn't mean to imply that the first method with the red cross is WRONG. I do it my way because it looks a little thinner when your done. Not to say that the other method doesn't work. Works fine. Just a little bit bigger joint when your done.

I know you should always have a mechanical joint when soldering. Kmot makes the U shape and laces them over each other. It works. It's a mechanical joint and would prevent the splice from coming loose in the event the extension was pulled on. I don't worry too much about it. Twisting the wires together does make a little bit of a mechanical joint, although not as strong as Kmots. I have also staggered my joints to keep the extension a bit thinner. It makes them easier to pull through a guide tube back into the tail. If you do them all together and end up with the "fat-n happy-boa" method--the extensions get too fat to pull them all through a rocket tube.

I figure, if that servo extension gets jerked hard enough to pull the wires loose--I got bigger problems than just one servo not working. [X(] HEADS UP IN THE PITS!!! By the time I figure out the servo extension got ripped out--the plane has already been bagged and buried. [sm=red_smile.gif] Dumb Thumbs Disease sucks.

tukkus 01-11-2007 05:19 PM

RE: Why is it so hard to make servo extensions?
 
If you want to make your own wires then a Molex crimper is the tool you should get.... they are expensive but they will do a good job, you'll also need the right pins and housings... there is a little trick to the crimper, nothing difficult but if you've never used it before it would be fustrating to make a good crimp

I was about to buy the supplies to make my own wires until I found this site .... http://www.tanicpacks.com/catalog/index.php?cPath=54

they are 22-28awg wires for JR and Fut with all different lengths.... I've already ordered (5) 4" , (5) 6", (5) 8" and (5) 12" wires and 100 7/16" button head screws for a cost of about $27 and that was including shipping

I'm going to order more because i can't tell the difference in quality from the JR servo extensions that I have

jzinckgra 01-13-2007 03:33 PM

RE: Why is it so hard to make servo extensions?
 
I decided to go with the splice and solder method. But, I am using Hitec 22G wire and I think the wire coming out of the servo is 20G, maybe. It definately looks a little thicker on the outside. Is it wise to solder two different gauge wires together, especially when using digi servos? I have the hitec 5985 servos.

Hurri 01-13-2007 05:02 PM

RE: Why is it so hard to make servo extensions?
 
No Problem , they are so close in size , will be ok .

grimmy55 01-14-2007 04:20 AM

RE: Why is it so hard to make servo extensions?
 
servo arms how do I make ext for them the standard ones sometimes are to short (have you seen how much a pack of them are worth an arm and a leg they are going for )


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