Slick little waterproof electrical connector

so I happened across the following ip67 rated connector pair the other day. I got a few free samples of the housings (waiting on pins) at work.


www.molex.com/molex/products/datasheet.jsp
www.molex.com/molex/products/datasheet.jsp

I am waiting on my pin order to come in but I plan to replace my servo connectors with this connector and see how they work. pins are rated at up to 3A. they are fairly low cost from mouser, in low volume, at about 5$ per connector set including pins... cost decreases rapidly with volume.


I will keep you all posted, but from the initial fit and look, they are promissing...

 

So the following review comes with a couple of disclamers

1. I only used tools on hand, no special crimper that the pins technically want, nor the special rear seal block installation tool, I used plyers.
2. Water depth is insufficient for anything other than a scoping test. that being said, most waterproof/splashproof servos I tested that way failed the overnight dunk test, so a good scoping test it is.

Notes so far

1. Pin installation and crimp
   1. crimp with needle nosed plyers to shape shown in datasheet. not easy the first time but very easy the second. not an issue for us. For future ones I might partly crimp then solder but I am not sold on that
   2. installation of pin into connector... have a small rod with no burrs to push pin into housing.. it is stiff.
2. aft end waterproof seal
   1. seal is compressed by a back plastic plate (intended for one time use). installation with plyers is a pain but doable. for our purposes I probably will remove the compression block and just scotchkote the back end.
3. Central seal
   1. as expected, this seal is also stiff. would benefit from the use of dielectric grease both for installation and removal and long term submersion/open-close cycle life
   2. I will see tomorrow how well the seals worked
4. Overall.
   1. minor pain to install pins without proper tool (not too bad)
   2. probably will modify with scotchkote to remove need to compress back end seal
   3. Looks promissing right now... I will be outfitting the littorio with these on all signal lines. the standard servo connector will be installed in the receiver and scotchkoted in place to seal or soldered (tbd)
   4. power lines will be the XT60 connectors from HK, scotchkoted on back and dielectric grease on mating surfaces.

 

So here is the lowdown... the aft seal only works with the correct diameter of insulation (servo wire is not that). to get around that, a little skotchkote on the back end and some dielectric grease (to ease insertion and removal) and I found no water inside the connector after ~12 hours submerged in the cup... needs real battle time but right now it is already superior to standard servo connectors. I'd recommend at this juncture that other folks play with them

.

 

there actually is a seal between the pairs, and this is a big deal. the back end is required due to me not using sufficiently large diameter wire. grease really helps just for insertion and removal. I've learned over the years to not trust the hope that just grease will keep anything out.. grease + seal and it does good, generally. I am also a fan of positive locking and enough finger room to actually grip them and take them apart rather than pulling wires (my big fat fingers have trouble with all the deans style connectors). I've got several more pairs I plan to try with larger wire to see how they do with correctly sized insulation (the servo wire is 0.025 inches smaller in OD than the smallest allowable OD wire for the connector).

they are not what I had hoped they would be (out of the box perfect for our use) but time will tell how they hold up. They do warrent actually following the spec on wire size (which I will do this weekend hopefully, with an update, that will teach me not to muddle through the half japanese half english spec and miss wire size limits)

Now for cases that you need more than the 3A rating, I have not found low cost connectors with any attempt at sealing (plenty of circular ones but they are larger than optimal and expensive (still looking around, I have needs at work for connectors with our requirements so I get some time to hunt)

 

So when I follow the specification and use the correct OD size on the wire (achieved via heat shrink) and install the aft end clamp evenly, the grommet at the back end fills in much better. this set is currently underwater, will check tomorrow

 

wonderful news...

when the correct diameter insulation is used and the aft end part is pressed in uniformly, the connector passes the scoping test I have above. now that I know what I have to do to get them to seal without using grease or skotchkote, they are going in the rest of the boat.

see below for installation requirements

Insulation OD: 0.070 inches minimum... spec says 0.070 to 0.074 but it seems to be assemblable up to about 0.085 although the aft end gets a bit stiff/

servo wire leads: for the standard servo leads. a single piece of heat shrink tubing will take the ~0.050 inch diameter leads up to >0.070 inches. some of the heavy duty servo lines have leads at about 0.068-0.070 inches to start.

 

see below for how I assembled the connector without buying special tooling:

1. servo leads with 0.050 OD wire
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2. Servo leads with heat shrink to increase wire diameter above 0.070 . Note very short length of wire sticking out end, that is important. the mid section heat shrink is there to cover the not connected red wire since this is destined for an ESC and I am using a separate low voltage regulator.
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3. Male connector parts. dissassemble to this level before beginning
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4. Crimping: insulation in first crimp region, wire in second. wire must not extend into third region of connector. Use plyers to fold one tab over wire, then fold other. do same with insuation crimp. I soldered for good measure but then again, I solder everything for good measure. do not add much solder if you go that way.
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5. Completed crimps
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6. completed crimps with solder
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7. Clamp and grommet installed on wire, note orientation
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8. pins inserted into connector
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9. Grommet reinserted into connector. don't push with sharp objects and fully seat it where it was before removal
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10. Clamp installation tools. use to compress clamp straight into connector. last snap may have to be done one side at a time.
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11. Clamp reinstalled but not compressed
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12. Connector fully assembled. for longer term exposure to wter, heat shrink tubing with adhesive or sealing the back end of the heat shrink is needed. of course had I bought the right size of wire ( 0.070 to 0.080 inches OD) then I would not have had to heat shrink the wire to match what the grommet needs
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