Lesson learned: Bullet connectors

[njswede]

I had a bullet connector where the male and female fit together a little loosely. Since I always put an extra piece of shrink tube over the connection and there's no chance they'll pull apart, I didn't think much of it.

Well, yesterday my 51" Slick had a dead stick (with a perfect landing, mind you!). It turned out that the factory installed male bullet connector had NO SOLDER on it. It was just held together with the shrink tube. A couple of emails with the motor vendor, and we figured out the culprit was the loose connector. Vibrations had probably caused some arching and heated up the connector to melting the solder and my spins and poptops probably did the rest to spread the solder all over the place.

So even if your slightly loose connector will be held in place by the shrink tube, don't fly with it! Switch to a connector that fits snugly instead. It may save you a plane...

 

[dskuro95]

Ever since my fiasco with the 72" before the maiden, I have direct soldered most of my motor to esc wires. IMO I think this is the best way to eliminate issues like this.

 

[njswede]

Yeah, I was thinking of you and your 72 and I may just solder the thing and be done with it.

 

[dskuro95]

Up to you, but I would.

 

[SnowDog]

I've recently started switching all my planes to Anderson Power Poles...really like how these go together.
But I also agree that direct solder is probably the most reliable way.

 

[Joe's Dad]

had NO SOLDER on it.
some arching and heated up the connector to melting the solder
to spread the solder all over the place.

Just curious. If the connector didn't have any solder on it. Why would heating it up melt the solder all over the place?

 

[njswede]

Just curious. If the connector didn't have any solder on it. Why would heating it up melt the solder all over the place?

I think it had solder on it before it melted... But I'm a bit surprised I found NO solder anywhere. The connector was installed by the factory...

 

[Joe's Dad]

I think it had solder on it before it melted... But I'm a bit surprised I found NO solder anywhere. The connector was installed by the factory...

Maybe the wire was tinned but never actually soldered to the bullet?

 

[cwojcik]

I've melted the alligator clips on my charger because the bullet didn't fit well. The high resistance of the bullet made it heat up from all the current it was passing, which caused a huge amount of heat (P=I^2R)

 

[Rolling.Circle]

Somebody should do an instructional video on solder joints and show a couple cold joints vs good connections. Deans and bullets both. I know we would appreciate watching tips on that. Look at shrink size to use vs. wire size etc... could be good. Hate when you get the bullet and the wire hot enough to get a good fit and find out that the shrink has shrunk.