A second KStep does not operate the rotary fourth axis, while the original KStep continues to run the X, Y, and Z axes. The evidence points to an incomplete configuration or axis-mapping diagnosis rather than a confirmed hardware failure.
Observed behavior
| Configuration or change | Observed result | Diagnostic meaning |
|---|---|---|
| Original KFLOP/KStep arrangement restored | X, Y, and Z operated; rotary did not | The established three-axis configuration still functions. |
| Four-wire jumper removed and outside voltage supplied | Only the rotary moved when commanded with the X-axis button | The rotary drive path can produce motion, but the command-to-axis mapping requires inspection. |
| Four-wire jumper restored | No confirmed fourth-axis operation | The jumper is required, but restoring it alone did not resolve the reported problem. |
Separate confirmed facts from hypotheses
Confirmed facts are limited: the four-wire jumper between the KSteps is required; X, Y, and Z work in the restored arrangement; and the rotary axis moved from the X-axis command during one altered configuration. The evidence does not identify connector pin assignments, channel numbers, supply ratings, firmware, or a specific failed component.
The rotary response to the X-axis button supports a configuration or mapping hypothesis, but it does not prove the cause. The initialization C program is the missing evidence needed to determine how the fourth axis and second KStep are assigned and enabled.
Diagnostic procedure
- Restore the four-wire jumper between the KSteps. Do not continue testing with a known-required interconnection removed.
- Return the KFLOP and KStep wiring to the last configuration in which X, Y, and Z operated normally.
- Record the complete interconnection arrangement, including which KStep drives X, Y, Z, and the rotary motor. Preserve the distinction between KStep drive modules and stepper motors.
- Capture the initialization C program used during the failed fourth-axis test.
- Compare the program’s rotary-axis assignment with the observed behavior. Because the rotary moved from the X-axis button, specifically check whether the rotary output is assigned to the X-axis command path instead of the intended fourth-axis path.
- Retest X, Y, Z, and rotary commands individually after correcting any confirmed assignment mismatch.
Verification and escalation data
A successful result requires X, Y, and Z to retain their normal responses while the rotary motor responds only to its intended fourth-axis command. If the rotary still fails, provide the initialization C program, the exact wiring arrangement, the intended axis assignments, and the observed response to each axis command. Without those details, the evidence cannot distinguish a program assignment error from an interconnection or hardware problem.
FAQ
Why does my second KStep not operate the fourth axis?
The evidence does not establish one cause. Restore the required four-wire jumper, then inspect the initialization C program and fourth-axis assignment.
Why does the rotary axis move from the X-axis button?
That observation supports a command-mapping or output-assignment mismatch. Verify the initialization C program before replacing hardware.
What information is needed to troubleshoot a KFLOP fourth axis?
Provide the complete wiring arrangement, which KStep drives each axis, the initialization C program, the intended behavior, and the actual response to each axis command.