CNC Manual, Part 4: Troubleshooting & Maintenance

Part 4 of the Velocity CNC router manual. Covers what to do when something goes wrong, and the upkeep that prevents most of it.

If Something Goes Wrong Mid-Job

Stop first, diagnose second. Feed Hold pauses the job in place; E-stop kills all motion immediately. When in doubt, E-stop – you can always restart a job, but you can’t undo a crash.

Common Issues and What to Check

  • Tool isn’t cutting to the depth you expect: almost always a zero problem. Re-check your Z zero (Part 2) before assuming a tool or software issue.
  • Toolpath runs in the wrong place on the table: check that your CAM work-zero setting actually matches where you zeroed the machine, and that you didn’t skip a zero step after the last job.
  • Spindle won’t start, or faults on startup: confirm you ran the Spindle Warm-Up macro (Part 2) and that dust collection and any interlocks are satisfied.
  • An unfamiliar fault code or error message pops up: don’t clear it and re-run blind. Read the message, note the code number, and if you’re not confident it’s safe to proceed, get a shop lead.
  • You see repeated “resend” messages or communication errors between the control and the machine: stop the job and get a shop lead immediately. This exact symptom was investigated and resolved as of the July 15, 2026 write-up (see below) – if it’s happening again, that’s worth reporting right away rather than working around it.

Routine Maintenance (Every Session)

  • Clear chips and dust from the table, rails, and spoilboard before and after use.
  • Check that dust collection has good airflow at the hose – a clogged line is both a safety and an air-quality issue.
  • Confirm the plenum is fully seated over the vacuum table before starting dust collection – a shifted plenum lets dust bypass the vacuum table entirely (see the photo in Part 2).
  • Visually check your cutting tool for chips, burning, or excessive wear before starting a job.
  • Confirm clamps, vacuum hold-down, or fixtures are securely seated before every run – don’t reuse “close enough” from the last job.

Routine Maintenance (Periodic – Shop Lead / Scheduled)

  • [Add this shop’s actual schedule – e.g. way/rail lubrication interval, gantry belt tension checks, dust collector filter changes, spoilboard resurfacing.]
  • Back up the CNC12 macro folder (C:\cncm\) before any planned software or button changes – see the VCP Skin & Macro Customization Guide.

For Shop Leads: Deeper Technical Reference

The Troubleshooting The CNC – July 15, 2026 write-up documents the underlying macro-level debugging and the Ethernet communication investigation in full technical detail, including the specific macro edits, parameter values, and the resend-error root-cause work. That level of detail is for whoever maintains the control software, not day-to-day operators – members who hit a real issue should flag a shop lead rather than working from that post directly.

When to Stop and Ask for Help

As a rule: if you don’t recognize an error, if the machine does something you didn’t command, or if you’re improvising a fix you haven’t been shown before – stop and ask. Nobody is expected to debug the CNC control on their own, and no job is worth risking the machine or yourself over.

Previous: Part 3 – Software & CAM Basics. Back to Part 1 – Safety & PPE.

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