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The Quest for the Perfect Power Connector

Our system involves a lot of actuators that are powered off a 12V source. If all actuators are stalled at once, you’re looking at about 20A of current. This demands some pretty beefy wires and power connectors if this worst case scenario ever occurs, otherwise we might burn something.

When I first started investigating power connectors, I thought of Molex connectors – like the ones you’d find in your average desktop power supply. The only problem is these connectors can actually really only handle 6-10A, at least according to’s datasheets: (

On the same site, I found some connectors that looked a bit more up to the task:

The HCS-125 connectors can handle 12-20A, according to their datasheet (

These seem to do the job, so I’ll stick with these. I realize I’ve only looked at one manufacturer, but frankly I trust Molex to make good quality power connectors.

Now the next issue is how to assemble the actual cables. On the side I’ve been looking into cable assemblies for the motor data lines, and manufacturers charge a LOT of money for crimping tools, which are designed for a specific series of connectors – they’re not universal. Take a look at this:

How ridiculous is that? $189 for a stupid crimping tool. I guess it makes sense – the demand for the crimper for this SPECIFIC line of power connectors is probably pretty low, so their profit margin has to be high.

Anyway, I expect to run into the same problem for the HCS-125 connectors. I can buy the connector housings, the wire crimp ends, but the crimper itself costs a fortune. Maybe I can get buy with soldering the wires to the wire crimps? I dunno. I’ll let you all know what I come up with in another blog post.

EDIT: It may not be the end of the world to just use pliers to crimp the wires…