A failed CNC spindle drive stops production. The immediate question is always: do I repair this one, or buy a replacement? The answer depends on three factors: the drive's age, the availability of a replacement, and the cost of downtime while you wait.
Option 1: Repair
Third-party electronics repair is widely available in the UK for most industrial spindle drives. Typical repair costs are 30–50% of new replacement price with turnaround times of 3–10 working days. The most commonly repaired faults are IGBT module failures, capacitor degradation, and power supply board faults — all of which specialist repair houses can diagnose and fix at component level.
When repair makes sense:
- The drive is less than 10 years old and the failure is a known serviceable fault (IGBT, capacitors, control board)
- A replacement isn't in stock and factory lead time is 4+ weeks
- The drive is an obsolete model where replacements are only available used or refurbished
When repair is risky:
- The drive has been repaired before — multiple repairs on the same unit suggest an underlying issue (contamination, overheating, or an external fault that keeps killing the drive)
- Water or coolant damage — if coolant has entered the drive housing, corrosion can cause cascading failures even after the visible damage is repaired
- The repair quote exceeds 60% of a new unit's cost — at that point, the risk/reward favours replacement
Option 2: Replacement
A brand-new drive from Fanuc, Siemens, or Mitsubishi comes with a full manufacturer warranty and typically outlasts a repaired unit. However, lead times can be brutal — 6–12 weeks for non-stock items from some manufacturers.
When replacement makes sense:
- The drive is 15+ years old and obsolete — repairing it is throwing money at a component that will fail again
- You find the exact part number in UK stock ready for next-day delivery
- The machine is production-critical and you can't afford the risk of a repair failing within months
Cost comparison (indicative UK prices):
- Fanuc Alpha spindle amplifier repair: £800–1,400
- Fanuc Alpha spindle amplifier replacement (new): £2,400–4,500
- Fanuc Alpha spindle amplifier replacement (refurbished with warranty): £1,400–2,200
- Siemens Sinamics S120 Motor Module repair: £900–1,600
- Siemens Sinamics S120 Motor Module replacement (new): £2,800–5,200
The Smart Approach
If you can afford the downtime, start with a repair quote. If the repair house can turn it around in under a week and the quote is reasonable, repair is almost always the better value. But order the replacement part number anyway — if the repair comes back and fails on test, or the repair quote is unexpectedly high, you'll have the replacement already on order rather than starting from scratch.
We stock the most commonly replaced Fanuc, Siemens, and Mitsubishi spindle drive modules in the UK. If your part isn't listed, contact us — we can often source within 48 hours through our supplier network.