a precautionary tale about power connectors

[mchahn]

I sent my simple metal in to the printrbot "spa" and it was great. I recommend it.

One thing done was my power cable setup was replaced because I bought a new supply from printrbot. The cable to the printer had free-hanging molex connectors that allowed disconnecting the power supply from the printer. This was well and good but apparently the connectors were not able to handle the current going to my printer and the heat bed. I noticed from the beginning that the connectors were warm. I assumed this was normal.

I was printing today and the print stopped. I checked the connector and this is what I found. I had to break the connectors apart with two pair of pliers.

20181012_184507.jpg

The moral to the story is that if a connector is warm don't ignore it. There could have been a fire.

[MartyS]

Since Printrbot is out of business the spa treatment is no more.

When I built my larger printer using a rev. D board I ended up soldering a micro deans connector directly to the board for the heated bed connection, to replace the normal one that was getting warm. Was also going to put a heat sink on the controller but after fixing the power loss at the connector it was not getting hot enough to need a heat sink.

Deans connectors are used in RC stuff a lot for the battery connections, made for high current and maintain good connection after many connect and disconnect cycles.