X axis only moves one direction

I am unable to manually move the machine to move towards me. The x axis only allows movement away from me. I should be able to move the machine manually but basically it’s locked in one direction. Does anyone know if there is some maintenance I can do to get it behaving correctly before I even turn it on? This is not an electronic problem, it’s physical.
It’s on a QCW table.

I do not use the 1F controller, and am not familiar with its software, but have a few ideas.

It is possible that the motor is not getting the Direction signal, only the Step signal. Double check that the cables are connected - check for loose pins in the connectors as well - along the entire path from motor to controller.

Sometimes it has to do with soft limits that are set, for example it is only allowing movement in the positive direction. Can you move in one direction, and back to where you started, or never back in the opposite direction?

You could try - carefully - testing the cabling by connecting the X axis cable to the Z axis port on the controller (not the Ys as they are slaved). It won’t be configured the same way, so just see if you can move it a short distance (1-2 cm) in both directions as a test.

How are you moving the axes - joypad, or on the MDI screen using commands?

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Hey Mitch,

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Hey Tom,

Only stepper drivers get step and direction signals separately. A behaviour as the original poster describes could result from one stepper coil not getting the pulses correctly.

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Hey Mitch,

do you mean, you give a command to move into one direction, and it moves, and you give a command into the other direction, and the axis does not move?

What do you use to give the movement commands to check this?

Does the issue also show up while running a g-code program?

Do you mean the movement of the two Y axis sliders, which hold the X axis? Does this issue appear exclusively on these?

If so, it is known that the Ys can block movement if your machine is not rectangular.
You should check the machine for rectangularity.

This is the “machine squaring” thread:

If you give the machine the command to move towards you, what does it do?

  • Simply nothing?
  • Or a noise?
  • Does it move a very little bit and then stops?
  • Do you get some kind of error?
  • On display, does the machine set the axis positions to zero as if it had homed?

What happens if you enter

G21
G91
G0 Y-10
G90

into the MDI field of the Tabbed Section of the Control Page?

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Thank you for your comments but this is not a software or controller problem. The unit should move by hand when turned off, it does not.

Hey Mitch,

yes, the commands I suggested are for letting the controller try to move it mechanically towards to you by one cm. What happens if you try this?

If you move both Y by hand by pushing the X rail away from you, you can’t do this exactly the same amount on both sides as the machine can with the commands executed by the two Y motors simultaneously

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Did you check all 9 points in this help document:

Also, did you check this mechanical issue:

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My apologies. I misread and misinterpreted your description of the issue.

Ok, I did not check all 9 points. I will proceed with “If your rail is getting hung, it could be dirt in the ball nut!” That’s my guess for now so I will work on it later today and let you know how it goes. Thank you all for your help.

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I cleaned the ball nut but the problem persists. The problem seems to be where the ball screw goes into the rear support. It’s making a sound like something is catching in there. The ball screw should move freely. Did anyone see a video anywhere on how to get in there. I can’t seem to get that plastic piece to move even after loosing the little set screw in it. Is there a gear connection of some kind between the stepper and the ball screw? Are there any diagrams beyond the manual? Any thoughts or ideas are welcome.

Hey Mitch,

between ball screw and stepper there is a coupler.

Did you have a look at the “Support” Playlist at OnefinityCNC’s youtube channel?

There you find e.g.

Did you also check point 7.) of Troubleshooting: Rail is getting hung, stuck, or out of alignment ?

Also I remember there was this mysterious issue some time ago. When an axis blocks, the stall detect function of the TI stepper driver chips is triggered which leads to the Onefinity controller thinking the axis has done stall homing and resetting the axis position value to 0.

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Ok - I think I got it, it’s jogging fine now. The coupler bolt on the stepper side had come loose. You can see it in the photo. That lead to being able to move in one direction but not the other.

I’m not very mechanical and I never RTFM (a bad combination), but we’ll take the win.

Thanks for the help.

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Thank you for sharing the solution.

Sounds like the thrust bearing has gone bad

no. It’s simply the coupler being loose, covered here as part of normal maintaince:

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Hey Mitch, hey all,

usually you wait monthes for the delivery of a Onefinity CNC machine. I have always thought that during the waiting period, all people…

  • Learn CAD/CAM (if they don’t know it yet).

:slight_smile:

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