NEMA 23 with connector on housing

(Neil Ferreri) #1

Anyone have a source for good NEMA 23s with a connector at the motor? I’d rather just unplug a wiring harness than replace a motor and wiring when something bad happens.
I guess I can keep cutting the prewired part back until I make a connector on the housing. :roll_eyes:

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(William Adams (Carbide 3D)) #2

Yeah, I keep telling myself I’m going to source 400-step motors with connectors on the housing and redo the whole thing, but I worry about the smaller steps not really paying off for increased precision/accuracy and causing problems.


(mikep) #3

I’ve only seen connectors on either smaller 17’s or on closed loop servos.

Here’s a smaller 17:

Interestingly, these guys now have an integrated driver that mounts on a 17/23 stepper too.

I’d still like to try a closed loop servo, but they’re just more cost than I’m willing to blow on a “might me neat”


(William Adams (Carbide 3D)) #4



(Neil Ferreri) #5

That’s what I was looking for, but a connector doesn’t justify spending that much more. I’ll rig something up.


(Neil Ferreri) #6

Here’s what I came up with for a prototype on this.

Uses these connector pairs and four M3x25mm screws.


(Julien Heyman) #7

Just curious, what usecase do you have for plugging/unplugging motors often enough that this plug will make it easier for you ?

Off-topic: I’m picking up my Prusa tonight, would you have any assembly tip? I browsed the assembly instructions & forums a bit and the only pitfall I spotted is to not overtighten things.


(bartosz) #8

I’ve had a very bad experience with aviation connectors mounted so close to the motors on my diy cnc. After few months started noticing that the machine was loosing steps and began acting erratically. After few minutes from the power up aviation plugs were getting very hot and upon disassembly discovered that most of the pins were badly burned. Not enough to completely loose connection though. It might just be my setup, maybe some of the components weren’t “happy” working together, maybe it was my soldering or some other reason to it, but after removing connectors everything is working perfectly.

I also have aviator plugs mounted on my electronics enclosure (far away from the motors) and they work just fine and don’t heat up at all.


(Neil Ferreri) #9

In building a new machine, I just wanted to avoid some of the problems. It’s not as much about plugging and unplugging as just making it easier to wire and replace wiring (in the event I’d need to). I haven’t had it happen on my XL (yet), but I’ve had to replace stepper wires on a few 3D printers after a lot of use. It’s just nice when you can unplug a broken wire and plug the new one in. I never liked the idea of a stepper extension / soldered connector being located in a drag chain. This way, the motor will never have to be replaced, but If I want to swap motors that would be easier too. It also looks cool :sunglasses:

Good info to have before I commit to this! Do you have a connector you’d recommend? It looked like most bigger CNC use a similar connector.


(bartosz) #10

I used those connectors for exactly the same reason. Figured it’s easier to just unplug the motor and swap it whenever I need but I was wrong. It takes forever to do a good job soldering those aviation connectors and you have to be very precise. I find it much easier to splice a wire and solder it. Takes me no time and I know that the connection is solid. Not sure I can recommend any other connectors as on my new build - ball screw so3 - I’m just going to use cable glands to make sure that the wires won’t get pulled out of the controller.

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(Neil Ferreri) #11

My original plan was to use a simple terminal strip inside the housing, but, like I said, in looking at what people use I found those aviation connectors. I never knew the name for cable glands…I always called them “fittings”. I might go back to the terminal strips and pick up some cable glands.

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(bartosz) #12

Because they are fittings after all, aren’t they? :wink:

I actually like that idea a lot more than aviation connectors. The enclosure that you designed will keep wiring clean and screw terminals are so easy to use. Besides every time you’d be changing a motor you’d have to solder a new aviation connector to it and trust me it was the least enjoyable part of the wiring process for me. It’s just my opinion though.

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(Neil Ferreri) #13

You’ll have no issues…pretty simple. Belts don’t need to be as tight as on a subtractive CNC. Use a decent hand driver instead of the allen wrenches. All in all, it’s really well designed. I still need to upgrade my extruder and find the time for the MMU.