[adamski07]

hi everyone. I have my mini cnc machine I bought 2 months ago. It was perfectly working last night until today where Z axis is doing some weird spins. when I hit "up" on my keyboard, it will go up then down for 2 second. Sometimes it goes all the way up. Same thing happens when I hit "down" on my keyboard. What could be the problem with the Z axis? X and Y are working perfectly fine. :drowning:

[vtx1029]

Low battery on a wireless keyboard?

[aarggh]

Have you checked the stepper couplings are tight? If everything looks good, swap the axis over for another one, and if the fault still affects the axis the cable may be suspect, if it affects the other axis now, the driver for that axis is faulty.

Check all the mechanical connections first though.

cheers,
Ian

[adamski07]

Low battery on a wireless keyboard?

I am not using wireless keyboard for this.

[adamski07]

Have you checked the stepper couplings are tight? If everything looks good, swap the axis over for another one, and if the fault still affects the axis the cable may be suspect, if it affects the other axis now, the driver for that axis is faulty.

Check all the mechanical connections first though.

cheers,
Ian

I have checked all the connection and it was fine. I'll try swapping the motors later to see if the problem is the axis driver. I am suspecting it is the one faulty.

[adamski07]

Alright after troubleshooting the system. I found out that it might be the cables problem. I am still not sure what's wrong with it.

First, I tried plugging the X axis motor with its wiring to the "z" controller and it works fine. Then I plugged Z axis with the cable to other controller and same thing happens it's acting up weird. Then I tried swapping the motors as well. The "Z" motor works fine in another connection. I tried the "x" motor to the "z" cable running on different controller and I am getting the problem. What do you guys think is the problem with it? I need help with this since I totally newbie with CNC machines and I need it to work now. thanks!

[aarggh]

You'll probably find there's a partially or completely broken solder joint on the connector. What commonly can happen is the cable gets stressed, and the wire strands at the solder point break, and either leave a few strands working, which can't then handle any decent current, or it makes contact intermittently depending on how bad the break is.

Check the wires at the point they are soldered to the connectors, chances are that's the problem.

cheers,
Ian

[adamski07]

You'll probably find there's a partially or completely broken solder joint on the connector. What commonly can happen is the cable gets stressed, and the wire strands at the solder point break, and either leave a few strands working, which can't then handle any decent current, or it makes contact intermittently depending on how bad the break is.

Check the wires at the point they are soldered to the connectors, chances are that's the problem.

cheers,
Ian

Thank you. I will ask my father to do it since he knows those electrical stuffs. Pretty sure it is the cable. Hope to get this fixed asap. Btw, I use this machine for my case modding hobby and I just got the case and wanted to start with it now.

[Fastest1]

A crimped connection is a much better type of connection for any moving wires. There must be a strain relief or attachment point of the soldered wires very close to its termination point or the soldered joint will break. Vibration could cause the break too. It sounds like you nailed the diagnosis. Just a cable, rarely does a stepper go bad from what I have seen.

[Dylwad]

Could be a break in a wire in the middle of the cable too, had the same thing happen when using cheap wire not rated for continuous flex.

[adamski07]

A crimped connection is a much better type of connection for any moving wires. There must be a strain relief or attachment point of the soldered wires very close to its termination point or the soldered joint will break. Vibration could cause the break too. It sounds like you nailed the diagnosis. Just a cable, rarely does a stepper go bad from what I have seen.

Alright. I'm trying to take off the "Z" cable and check what's wrong with it. I did double check it again twice and the problem is really in the "Z" cable. I'll have to find out what's wrong under the heat shrink tube.

[adamski07]

Got it working now guys. Took the whole "z" cable out and straighten out the wires. taped a stick on the bent one and it is now working. I am not doing this permanently, but for now, Im okay with it. I really need the machine now. I'll do another cable once I'm done with the project. Thanks for all the help guys