I know this is a rather old post, but I just bought some 3.5mm connectors for my motor and controller because I was always switching my BL system between my Maxx and Rustler and having to remove the controller with the motor at the same time was rather annoying.

Anyway, I was wondering exactly how you solder the gold connectors to the wire. My motor and ESC wires are pre-tinned, so I can't fit them into the non plugging part of the connector. Do you just solder the wire to the top of the connector? Also, can I put some shrink tubing on the female connectors so that they won't touch and short something out?

Thanx,
Brijar!!!

What size wires are they?

a non pre-tinned wire (12ga, 4mm2 fits in)

i had that problem too, i dremeled the holes in the 3.5 plugs a tad bigger.

Soldering them on top is a bad idea.
if you heaten up the pretinned wire, and clamp the plug you should be able to press the wire in as well.

They are the stock, regular wires that come on the Feigao 9L and Warrior 9920. I may have to untin them or cut off the tinned part. Are you supposed to solder the wire, or clamp it in the plug? I would prefer to solder it, as then it won't come out.

Brijar!!!

Don't cut the wire on your motor for it has a coating that make the solder not stick.

I usualy just take a fine file to the tinned wire and take off the high spots so it will fit into the connector. Its not removing much material, just enough of the high spots to get it to slip into the connector.

Best way I've found to solder on those bullet plugs is find a way to hold your plug upright (pliers with a rubber band around the handles or something). Then take a mini torch and heat up the plug. Then start filling the hole up with solder until it's about 3/4 full. Then quickly stick the tinned wire all the way into the hole while the solder is still real hot and liquid. Hold it there for a few seconds and shrink tube it and that's it. Much easier that way than with a soldering iron.

I read some of the posts for soldering direct vs plugs and thought of another reason to use plugs: reversing the motor direction. If you decide to mount the motor in another vehicle, then reversing the motor direction is much easier if you can unplug them.

As to soldering the plugs, I use a hot iron (100W). I tin the wire leads and the inside of the plug hole, then insert the wire in and heat the connector while feeding solder into the hole until filled (shouldn't be too much). Works well and looks good for me.

I've also soldered direct and found a trick that works quite well. I get a crimp-type yellow butt connector, remove the plastic shell, and then drill a 1/16" hole on one side of each end. I then stick both wires in each end, but don't crimp. 12GA wires are actually snug in the hole. Then I heat the connector and feed solder into the hole i drilled into the side. When cool, I slide heatshrink tubing over the connection. Because the thickness of the connector walls is about the same thickness as the wire jacket, the heatshrink almost looks like there is no connection with no solder bulges.