Conductive Lubricant for Connectors?

Question

I'm making a safety disconnect for an experimental RC craft. It will be tethered to the ground, and if it goes out of control the tether will pull a plug disconnecting the power. I will make the plug from a male Deans connector (pictured below) looped to connect the positive and negative terminals. The female connector will be in line with the battery.

What's the best material to lubricate this connection? I would like the plug to disconnect as smoothly as possible when tugged by the tether. In general, what are the most common connector lubricants that are (a) conductive, (b) will not cause shorts, and (c) not messy?

(a) and (b) are pretty much mutually exclusive. I would recommend dropping requirement (a). — Dave Tweed, Sep 05 '12 at 22:46

score 9 · Answer 1 · answered Sep 06 '12 at 05:39

9

In marine applications silicone grease is used on all copper contacts for corrosion resistance: water-resistant, non-corrosive, etc.

answered Sep 06 '12 at 05:39

ARF

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HikeOnPast · Accepted Answer · 2012-09-06T02:38:05.670

7

The lubricant does not need to be conductive - the contact pressure between connector halves will push the lubricant out of the way and ensure a good connection. A wide range of lubricants will work for your application. Try dielectric grease (sold for starter battery terminals), petroleum jelly, or WD-40 (wiped, not sprayed). As long as it is very liberally applied and doesn't chemically attack/soften the plastic shell of the connector, it will likely work just fine.

Be sure to mechanically strain relieve the assembly so that the connector housings take the load during disconnect rather than the conductors. If you had a bad crimp on the battery side of the connector, you might pull the connector right off the battery leads during the disconnect event, allowing them to short together directly. Not recommended!

edited Sep 06 '12 at 02:38

answered Sep 06 '12 at 00:00

HikeOnPast

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Good point about strain relief. I'll be sure and do that! – Mark Harrison Sep 06 '12 at 00:18
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Do not use petroleum jelly, or WD-40. Petroleum jelly (vaseline) has a low melting point so it will deteriorate away if the connector gets even warm. If it will melt chocolate, it will melt vaseline. Also, vaseline is flammable. It's a great way to start a fire. In fact, some people use cotton balls or rags soaked in Vaseline as firestarters. WD-40 is not a lubricant, it is for displacing water (WD = water displacement). It will dry up quickly and the residue is not healthy for the connector. Like vaseline, it is flammable (until it dries up). – Tyler Durden Aug 14 '18 at 20:42

Curd · Answer 3 · 2012-09-06T13:24:09.300

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If you really insist on something that

is a lubricant and
is somehow conductive

graphite powder comes to my mind.

It is commonly used as lubricant for locks.
I don't know, however, if it is a good idea to use it for connectors.

Here graphite is recommended also for electrical connectors.

edited Sep 06 '12 at 13:24

answered Sep 06 '12 at 09:50

Curd

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score 2 · Answer 4 · answered Sep 06 '18 at 12:07

It will be difficult to control the insertion/removal force this way.

Connectors with defined force like USB have dedicated springs for this, and keep load on the conducting pins low.

I'd probably use a magnet to define the removal force (which can then be adapted by changing the distance between the magnets), and two simple contacts pressed onto each other by the magnets for the actual connection.

Conductive Lubricant for Connectors?

4 Answers4