Hey guys,
I’m looking for a recommendation for 4 wire plugs that I can use for my NEMA 23 steppers. Currently they use old school 4 wire PC power plugs, like you would see on an old IDE hard drive. These are OK, but really aren’t meant to be plugged and unplugged often. I have a sort of a modular system, so I am often disconnecting them. I am looking for something that comes apart easily, but is also secure.
Thanks for any advice!
The nice thing about the big barrel connectors you have now is they can handle the current of a stepper indefinitely. There are a lot of smaller 0.1" pitch headers that are keyed and latching, but depending on how big your steppers are, they’re likely to be at or beyond their rated current.
Hi John, thanks for the idea. When I search for barrel connectors, I just get the barrel connectors used for power connections like the ones on wall warts. Do you have any links?
I am using aviation plugs like this: https://www.ebay.com/itm/112119564762
They’re an industry term, as opposed to pins, which are solid. I just realized: molex mini-fit junior connectors might be what you need. https://www.digikey.com/products/en/connectors-interconnects/rectangular-connectors-housings/319?k=molex+mini-fit+jr&k&pkeyword=molex+mini-fit+jr&pv518=21&FV=ffe0013f,1600006,16400b3&mnonly=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25 shows some. They clip/unclip a LOT more easily than the power connectors. You do have to crimp up your own terminals, and that’s kind of a drag. The official molex crimpers are ruinously expensive but there are much less expensive, quality crimpers out there.
Example of a halfway decent crimp tool that I believe will handle molex mini-fit terminals: https://www.amazon.com/Professional-Ratcheting-70005-Insulated-Terminals/dp/B017JX8W2I
That’s 1/15 the price of the official Molex crimper. I have one very similar and it does a great job. Here’s why I recommend this type: a ratcheting crimp tool will always produce a good crimp on both the insulation and the wire sections if you prep the wire right. The repeatability is extremely good. If you try doing these individually with a non-ratcheting one, you risk crimps that come loose or sever wires. Definitely positively do not try to do this with needle nose pliers.
I do not recommend soldering, either, at least not on cnc equipment, because the solder makes the copper brittle and the repeated flexing as the stages move around will end up with the copper breaking at the very edge of the solder joint.
btw I really like these guys: http://www.deutschconnector.com/products/deutsch_connectors/deutsch_dt_series_connectors/deutsch_dt_4-way_connectors/ but they’re not cheap and for most machinery they’re total overkill. But if you need your motor connection to survive being immersed in flood coolant full of metal chips, they are the right choice.
Thanks for the great info John and Sebastian. John, I know what you mean about the crimper cost. I looked into it many years ago and was shocked.
Db9 are good been around for ever, cheap and available