A used CNC machine is only a bargain if it cuts accurate parts on your floor. The difference between a sound machine and an expensive rebuild shows up in the spindle, the ways, the control, and the paperwork — not in the photos. This checklist covers the twelve checks to complete before you commit to a purchase.
What should you inspect first on a used CNC machine?
Start with the spindle. It is the most expensive component to replace and the clearest indicator of how the machine was run. Listen for noise or rumble at low and high RPM, check for radial play by hand, and look for coolant or oil leaking from the spindle nose.
Spindle condition dictates whether the machine holds surface finish and tolerance. A worn spindle bearing produces chatter and taper on finished parts that no amount of program tuning corrects. Ask for the spindle hour count, whether the spindle has ever been rebuilt, and confirm the taper — CAT40, BT40, CAT50, or HSK-A63 — matches the toolholders you already own. Mismatched tapers mean re-tooling the whole machine.
How many spindle hours is too many?
There is no universal cut-off. Spindle hours matter less than how they were accumulated and maintained. A machine with high hours in a well-run production shop with documented maintenance is often a safer buy than a low-hour machine that sat neglected or ran heavy interrupted cuts.
Read hours alongside the machine's age and duty. Ask whether the hour meter records spindle-run time or total power-on time, since the two give very different pictures. Look for a maintenance record: way lube intervals, coolant changes, filter replacements, and any spindle or ballscrew work. A seller who produces service history is telling you something useful about how the machine was treated.
How do you test a used CNC machine under power?
Insist on an under-power test. The machine should be energised so you can run each axis through its full travel, run the spindle up through its RPM range, and cycle the tool changer. A machine sold without a power-on demonstration carries substantially more risk.
Watch and listen through the test. Axes should move smoothly with no grinding, hesitation, or alarm codes. The spindle should reach top RPM without excessive vibration. The tool changer should complete a full cycle and return to position — ATC faults are common and can be costly. If possible, cut a test part or run a program that exercises all axes together.
What should you check on the CNC control?
Identify the control make and generation — Fanuc, Siemens, Mitsubishi, Heidenhain, or Mazatrol — and confirm parts and service support still exist for it. Power up the control, clear and review any active alarms, and check that the screen, keypad, and memory all function.
The control is where obsolescence bites hardest. Older systems can still cut excellent parts, but replacement boards, drives, and servo motors get scarce and expensive as a generation ages. Confirm the machine's program storage and transfer method still fits your workflow. If a control is nearing end of support, price the risk into the offer, and know that replacement drives, boards and servo motors can keep an older machine running.
How do you check axis and way condition?
Move each axis through its full travel and feel for backlash, binding, or noise. Inspect the way covers and wipers for damage, and look under them for scoring, rust, or dry ways. Worn ballscrews and ways show up as positioning error and poor surface finish.
Way and ballscrew wear is the second most costly problem after the spindle. Check whether the machine uses box ways or linear guides, since the wear behaviour differs. Look for evidence that way lube was actually reaching the surfaces — dry, scored ways point to a neglected lubrication system. If the seller allows it, an indicator sweep or ball-bar test gives a measured picture of geometry rather than a subjective one.
What condition should the coolant and lube systems be in?
Check the coolant tank, pump, and lines for sludge, rancid smell, and leaks, and confirm the way-lube pump delivers oil to every point. Neglected fluid systems are a reliable signal that other maintenance was skipped too.
These systems are cheap to inspect and revealing. A tank full of sludge and tramp oil suggests coolant was never managed, which accelerates corrosion inside the machine and shortens tool life. A failed way-lube pump is inexpensive on its own but often means the ways beneath have already run dry. Chip conveyors and coolant filtration should also run without jamming.
What tooling and accessories are included in the sale?
Confirm in writing exactly what comes with the machine: toolholders, collets, chucks, a full or partial tool magazine, vises, fixtures, the rotary table, manuals, and any spare parts. Tooling assumed and not documented is the most common post-purchase cost surprise.
A machining centre with a 24-pocket magazine and no holders needs a full set of CAT40 or BT40 toolholders before it earns a dollar. A turning centre may need chucks, jaws, and a tailstock centre. Price the missing items into the deal rather than discovering them after delivery, and get the included list written into the invoice.
Will the machine run on Canadian power?
Confirm the machine's voltage, phase, and full-load amperage before purchase. Canadian industrial shops run 575/600 V three-phase, while many US-sourced machines are wired for 460/480 V and need a matched step-down transformer (600 V to 480 V) to operate correctly in Canada.
Power compatibility is the most overlooked cost on cross-border used-machine buys. An undersized or missing transformer risks the drives and spindle and stalls commissioning after the machine lands. Establish the requirement early, price the conversion into the total landed cost, and confirm your shop's incoming service and breaker capacity can carry the machine.
What documentation should come with a used machine?
Ask for the operator and maintenance manuals, electrical and parameter schematics, the parameter backup, service records, and the original build specification. Documentation makes a machine far easier to commission, program, and repair.
A parameter backup is particularly valuable. Losing parameters on a machine without a backup can turn a simple fault into a lengthy recovery. Manuals and electrical drawings shorten every future service call. Where a machine has changed hands several times, ask about ownership history and any major repairs — a single-owner production machine with full records is a materially different proposition from an auction machine with no history.
The 12-point checklist
Work through these in order before you commit:
- Spindle — noise, play, leaks, hours, rebuild history, taper type
- Spindle hours vs age — how the hours were accumulated, and maintenance records
- Under-power test — full axis travel, spindle through RPM range, no alarms
- Tool changer — complete ATC cycle, pocket count, no faults
- Control — make and generation, active alarms, parts support still available
- Axes and ways — backlash, binding, scoring, way covers and wipers
- Ballscrews and geometry — positioning accuracy, indicator or ball-bar check
- Coolant and lube systems — tank condition, pump function, delivery to all points
- Tooling and accessories — documented in writing on the invoice
- Power compatibility — voltage, phase, amperage, transformer requirement
- Documentation — manuals, schematics, parameter backup, service history
- Total landed cost — machine, transport, rigging, transformer, installation, tooling
Point twelve is the one buyers most often underestimate. The purchase price is only part of the number; rigging, transport, power conversion, and commissioning all belong in the comparison before you decide whether a machine is genuinely a good deal. That total-cost view is also what makes the used versus new comparison meaningful.
Where can you buy inspected used CNC machines in Canada?
Gizmo Machine Tools sells engineer-vetted used CNC and conventional machinery from Mississauga, Ontario, with delivery across Canada. Buying from a dealer that inspects, tests, and services machines removes most of the condition risk that comes with private and auction purchases.