X axis stepper not fully spinning, just growling

I’ve got email into Carbide Support. But check out my 2 emails and maybe just maybe someone here has experienced this. I just installed a new X stepper but the problem is the same.

"So I did some light troubleshooting. The X stepper is making the noise and not moving as it should. If I push on the carriage it sort of limps in the direction of home. I accessed the connectors in the chain and isolated the X motor. It growls like crazy and struggles to turn. Belt is tensioned normal, carriage moves smooth when power is off. "

and today,

" I just installed a new X motor but it didn’t solve the noise (sort of growling) and not moving during the Initialization phase. I can push the carriage along but it doesn’t continue to move on its own, stops and keeps growling.

Attached are 2 pics of my control board. I can also film it if that helps the troubleshooting. So speaking of additional troubleshooting, any suggestions for me to follow?"

I’m not savvy on control boards and such but I have to believe these GRBL control boards we have must have Drivers? I’m going to try uninstalling Motion and reinstalling.

Reinstalled Motion. During initialization it’s the same grinding mess. I can push it along and it begins to move by itself and the limit switch stops the carriage and then the carriage tik toks back and forth. What a mess.

I’ll wait for Support.

Check your wiring connections. Pull on both sides of the stepper motor connector. Sometimes the connectors pull out and make a bad or high resistance connection. See if you see any discoloration that would indicate a heated connection. What is common between the two stepper motors is the connection.

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Are the connectors on the motor the same as the connectors on the wiring harness that plug onto the control board?

If so, take the motor and plug it directly into the control board. If it now moves normally, then it’s a wiring problem. If it’s still broken, then it’s either a motor problem (unlikely, since you have the problem with two motors), or a control board problem.

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Clever idea about plugging in the motor directly. I’ll keep that one in mind. After I posted my first update I grabbed my ohm meter and started wringing out the X wire bundle. 4 wires and the white one has no continuity. I freed it from the machine, ohm’d it again and still no continuity on the bench. There’s 2 sharp indents along the cable. Not cut into the bundle but certainly it was pinched.

I’ll contact Support about getting a new X bundle. Tnx awfully for your quick responses.

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All the symptoms of a wiring issue. Which machine?

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It’s a Shapeoko 3xl.

Probably happens or will happen to all of them.

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As has been said this is almost certainly wiring, though it could be a bad stepper motor driver or a bad stepper motor. Sounds like only one of the two sets of coils in that stepper motor is getting energized. Stepper motors have two sets of coils (for the most part). They work by energizing those coils at different times and different power levels causing the specially designed stator inside the motor to align with overall magnetic field of the two coils. In other words step. If only one of the coils gets energized it will cause the motor to not move and make a buzzing sound as the one coil cycles.

To check if the stepper motor is bad take a multimeter and check for continuity between the four wires. You should find two sets of wires that measure as being connected together. Then measure the resistance of those two sets of wires. they should measure the same. If you only find one set of wires being connected together or you find that one set of coils has a dramatically different resistance than the other the motor is bad. For instance I had a 3d printer with a bad stepper motor. One set of wires read 0.2 Ohms of resistance and the other read as 20 Ohms.

Once you find the two sets of coil wires note the colors of their wires. Plug the stepper back into the wiring harness and go to the end of the harness where the wires plug into the control board. Use your multimeter to again read continuity between the wire pairs. You should still read the same wires are connected together as you did at the motor. If not the wiring harness is probably bad. If so then something is either wrong with the connector to the control board or with the control board itself.

Hope this helps narrow things down. As always though you should contact support.

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Carbon tells me there was some arching.

These are the connectors that insert into the plastic part of the connector. The continuity of the connection hinges on the spring back of the metal. If over time the spring back weakens there could be enough resistance build up that arching will happen. Perhaps there was a more reliable connector that could have been put on the carbide drawing board. Stuff happens…

I will report back after getting a new wire bundle from Support.

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TBF to Carbide here.

This is a really well known problem with moving machines which is why the industrial preference is to use specially flex duty rated “screened control cable” in drag chains and never have connectors in the moving paths, always strain relieved from those moving paths.

When I ‘modified’ my machine, all the wiring I changed went to screened control cable, end to end, with the motor connections anchored at the ends of the drag chains to eliminate the movement that constantly works away at them.

At the time of these older machines the cost impacts of that specialist cabling and industrial grade connectors would have significantly hit the headline cost of the machine and made the upgrade kits more expensive too.

Here is an old picture of my “Z”. Since I did this I have not had issues. Yes, I took the AC out of the bundle, got to get a new pic.

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Well I found my continuity problem. This is far end of the X extension cable, where t
he motor first plugs in. Wouldn’t have guessed a wire to burn off at a soldered connection; the motors are such low amp. Support connected with me at the end of the day yesterday, I’m hoping they have a cable assemble in stock or can at least make me one. I have a 3xl that is out of production. :crossed_fingers:

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That’s where the lead is most likely to fail.
Could be a cold solder joint, bird caging or the lead was not properly in contact with the pin, i.e. floating in the solder.
The joint prematurely fails and arcing develop until the gap between lead and pin increases, resulting in loss of continuity.

Or the joint could have been OK and it’s broken because the soldering makes the wire brittle (in addition to all the other problems you listed) which is why crimps or wire wrapping generally preferred in applications subject to vibration and flexing.

If OP has a soldering iron I’d just re-solder that connection for now.

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Seems like a bad solder joint.

However there looks to be more then just a bad connection.

There are interesting marks on the pins. They are not smooth.
It is a bad angle but when I zoom in, it looks like the pins were over heated when soldered as there may be melted plastic marks around the pins. And the pins are not straight or the same depth anymore due to over heating. There appears to be an addition melt mark on the plastic body. Possible a misplaced solder iron.
The solder on the broken wire pin does not look like it flowed correctly. Nor was the proper technique used IMHO

It is a bad angle and I hate to say it but it looks like someone without soldering skills and proper experience with these connectors had a go at it. :frowning:

Its an OEM bundle, hope my new one will be good to go.

People solder those joints together. The old story was you did not want to buy a car that was made on Friday. People were just wanting to get out of the factory for the weekend and did sloppy work. I am not saying anything about C3D but people make mistakes. My SO3 (knock on wood) has been perfect and has not had any connector problems. So hopefully it is a one of and wont be repeated.

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