Accuracy Testing & Ballbar
Quantify what your machine is actually holding.
Your machine was accurate when it left the factory. Five years and 8,000 spindle hours later, drift is invisible until a customer rejects a part. Accuracy testing measures what's actually true today — squareness, circularity, positioning, repeatability — and gives you a documented baseline to work from.
What's Included
Scope of work
Specific to your machine list and shift count. Custom adjustments are quoted separately.
- Renishaw ballbar testing — measured circularity error broken out by error type (backlash, squareness, scaling, servo mismatch, stick-slip)
- Laser interferometer linear positioning and repeatability checks
- Geometry verification: spindle-to-table squareness, axis-to-axis squareness, parallelism
- Spindle runout (TIR) measurement at the taper and at tool length
- Compensation table review and update where measurements indicate drift
- Written report with measured values, comparison to OEM spec, and ISO 230-2 / ISO 230-4 references where applicable
Why It Matters
The business case
Scrapped parts cost more than testing. So does a customer audit that fails because you can't produce evidence of capability. Accuracy testing is also the right starting point before retrofitting, before a contract that requires tighter tolerances, and as part of a PM program for tight-tolerance work.
How It Works
The process
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Schedule
We coordinate around production. Most full accuracy tests need 2–4 hours per machine on the floor.
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Test
Ballbar runs across all axis pairs, laser checks on linear axes, geometry verification with precision squares and indicators.
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Report
Per-machine document with raw measurements, plotted error decomposition, and our interpretation.
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Compensation update
When measurements indicate the machine's compensation tables can correct for the observed drift, we apply the update on the spot. When they can't, we document what mechanical work would be needed.
Common Questions
FAQ
How often should I test accuracy?
Annually for general production. Quarterly for tight-tolerance shops or anything aerospace-adjacent. After any significant impact, after a controller battery loss, and before any major contract that demands documented capability.
Do you provide ISO traceability?
Yes — ballbar and laser equipment is calibrated and traceable. Reports reference the relevant ISO standards (230-2, 230-4) where applicable. Useful for AS9100, ISO 9001, and customer audits.
What if you find the machine is out of spec?
We tell you what's drifted, what compensation can correct, and what would require mechanical work (recoupling, ballscrew replacement, geometry correction). You decide how to proceed; we don't push parts you don't need.
Can you test machines we bought used?
Yes — accuracy testing is the right first step on any used acquisition. The seller's claims are claims; the ballbar tells the truth.
Other Services
Also worth a look
Preventive Maintenance
Scheduled inspections and service that catch failures before they cost you a shift. Coverage tailored to your machines and run hours.
Learn moreEmergency Repair
Machine down? We respond to emergency calls within 15 minutes during business hours and prioritize PM-contract customers for same-day dispatch.
Learn moreMachine Relocation
Disconnect, rig, transport, level, and re-commission CNC and manual machines without a scratch. We coordinate the rigging crew so you don't have to.
Learn moreRequest Service
Tell us about your machine and the issue. We respond to emergency calls within 15 minutes during business hours.
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