What wire gauge for servos ?

[DaveyP]

I am contemplating making up my own servo extension leads but not sure of what size of wire to use ?

Servos I've used so far are standard 311's  225's and mini hs40's any suggestions as to what wire gauge to buy.

Edited By DaveyP on 27/09/2017 10:59:19

[flight1]

Hi for standard servos and short distacnes awg24 is the one and for heavy duty awg22 . I always use twisted cable as it my preference and for many reasons. just make sure you get a desent crimp pliers

Edited By flight1 on 27/09/2017 11:07:32

[Cuban8]

One of my first jobs as a young technician was prototype wiring harness design for large print equipment. All manual, no CAD, done using the old bed of nails method. (watched a documentary recently about the NASA Saturn 5 rocket and that's exactly how they made their wiring looms as well, albeit on a huge scale)

The manual crimp tools manufactured by Molex that we used were several hundred pounds then (in the 80s) and gave a proper crimp joint both to the conductor and insulation in one action - in production the process was automated using sophisticated gear. Such a seemingly simple task of crimping a servo connector to a lead is open to problems that may not be readily apparent and could lead to failure at a later date if incorrectly performed using cheap tools and poorly prepared cable. The finished termination really needs to be gas tight to be correct.

I'd never bother making my own leads up now, but if you want to give it a go just remember to buy the best quality crimp tool that you can afford and look closely at how a commercial crimp is formed and copy that (magnifying glass). If you get any insulation trapped in with the conductor or vice versa, reject it. Also, take a look at the finished crimp terminal and look closely as to whether the terminal has been bent even slightly after the crimp process. The correct tool will perform the operation without any distortion to the terminal, thus making it able to fit and seat in its housing easily and avoid stressing the crimp 'spine' which might fail later.

Try a pull test on a sample of your work - the cable should break before the crimp fails.

Hope this is of use.

 

Edited By Cuban8 on 27/09/2017 11:58:08

[Andy Green]

Have you seen this I did some years ago, I've been making them for years.

Andy

[Cuban8]

That's a very good article that I'd not seen before and confirms what I'd said in my post. Providing you can get a crimp termination done to the quality exactly as shown in fig 6, then I'd not have any concerns.

[Geoff S]

I'd not seen that article before and it's a really good description of the process. I've been making my own extensions for years and have a cheap crimp tool a bit like the one illustrated but I replaced it with a much better rachetted one I got from Ash (of Ashlock fame) along with a load of his pins and connectors.

I just find it convenient to have wire and connectors in stock so I can get extensions the right length. In any case, if you want to use Ashlocks there isn't much choice, you have to make your own to suit the application.

I remember the 'bed of nails' jigs for making up harnesses from when I worked at GEC in Coventry and used the technique myself to make motorcycle wiring looms.

Geoff

[brokenenglish]

Posted by Andy Green on 27/09/2017 12:39:30:

Have you seen this I did some years ago, I've been making them for years.

Andy

That's really helpful. Thanks a lot!