Cannot get X axis to move

Reposted here from the FB Group:

I’m hoping someone here has seen this problem and has a resolution. I’ve checked the forum and didn’t see anything unless I missed it. I’ve just finished assembling the Longmill and just trying to jog the axis. Initially nothing moved but I didn’t have the plugs in all the way which I remembered was a situation some of you had. I was finally able to jog Y and Z axis without issues and that allowed me to secure the Longmill down. I am still unable to move X axis. I thought maybe there was a mechanical issue so I used Y output to drive X axis back and forth with no problem. I also also used Y motor cable and plugged that into X motor so I know it’s not a cable issue. When I command a jog I can feel the X motor vibrate slightly.
I would hate to think it’s the electronics and rather it’s just a problem with UGS in some way. I looked at the dip switches on the back of the controller and they looked ok. I didn’t flip them back and forth which I maybe should’ve tried but ran out of play time.
Ironically I fix large scale CNC machines for a living but this little one has me guessing, but still a few things left to try. I thought about scoping the output to see what signals I’m getting and comparing it to another axis.

2 months later…
Since the above post I have flipped the dip switches back/forth and tried the 32 & 64 bit version of UGS. X&Y share the same feedrate setting and Y moves fine so I don’t think it’s a matter of bumping up the feedrate. I have the step size at 100mm and feedrate at 1000. If I move Y it moves 100mm. When I try to move X, the position moves and I get some vibration on the motor but that’s about it. As I posted initially it’s not mechanics because I can drive X axis no problem using Y output on the controller.
Looking for some help/suggestions.

Hi Tony. Welcome.

Since you hear the motor humming it sounds like it’s getting the signals. One thing I can think of is I remember reading that some people have had trouble with having the eccentrics adjusted so that the v-wheels are too tight on the rails, and having the anti-backlash blocks so tight that the screw cannot turn. There’s only one X motor so it can be overpowered. Go back and loosen the wheels and blocks. Let us know if it helped.


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@Rokkin Tony: Just to get me over any confusion, you can jog the X, if you plug the X cable into one of the Y outputs on the controller, correct? So, it’s not a motor or cable issue.
Do you see 4 lights on your controller, one for each motor driver?
From what you are describing, it seems that the X driver is acting up. Keep in mind that I’m not anywhere close to an expert, nor do I play one on TV.

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I’ve loosened the nuts and can rotate the axis by turning the screw with2 fingers so it’s not mechanical. If I swap the X and Z outputs the X runs fine but the Z does not. I’m convinced it is the controller as well. I’ve also tried to adjust the current level with no luck. I will talk to Sienci to see if I can get another controller.

Tony, it sounds like you’re tried all the combinations of switching cables, motors, etc. so I have to agree with Grant that it may be the controller. At this point I’d go to Chris and Andy to see if they have something else to try.

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Yep…did that and I’m picking up another controller tomorrow. Thanks!

New controller in. Works like a charm.

@Rokkin Glad to hear things worked out, Tony. Have fun.

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