A gear grinding machine like the Reishauer RZ-150 represents significant investment. Whether you’re purchasing for production capacity, surface finish quality, or accuracy in high-precision gearing, choosing the right used unit can determine your competitiveness and profitability. Here’s a comprehensive guide to help you make a confident decision.

---

1. Understand What the RZ-150 Is

The Reishauer RZ-150 is a CNC gear grinding machine built in Germany and used in precision gear manufacturing. It’s known for:

• High surface quality (low Ra)
• Consistent profile and lead accuracy
• Efficient cycle times
• Solid mechanical design with proven longevity

Before pursuing a purchase, ensure the machine you consider matches your gear specifications and production demand.

---

2. Verify Machine Model & Revision

Reishauer produced several configurations of the RZ-150. Confirm:

• Exact model code
• Year of manufacture
• CNC control hardware and software version
• Spindle and grinding unit configuration

Older control versions can be still functional but may require interface upgrades or parts support.

---

3. Inspect Key Technical Specifications

Here are the most important technical parameters to verify and compare among used units:

Specification	What to Check	Why It Matters
Grinding Wheel Spindle Power & Speed	Confirm max speed & power rating	Determines grinding capability and material removal rate
Chuck Diameter / Workholding Size	Maximum gear diameter the machine can handle	Must match your largest gear requirements
Gear Module Range	Minimum & maximum module numbers	Defines the range of gear sizes it can accurately grind
Accuracy Tolerances	Verify actual test reports, if available	Confirms machine was capable of precision before sale
CNC Control Type	Siemens / Heidenhain / Bosch	Affects ease of programming, parts support, and training
Workhead & Tailstock Condition	Check for wear or backlash	Crucial for centering accuracy and repeatability
Coolant System	Functional and clean coolant system	Coolant quality directly influences grinding performance and wheel life
Hydraulics & Pneumatics	Leak-free and stable pressure	Essential for consistent clamping and safety operations
Electrical Cabinet & Wiring	Clean, labeled, and intact	Poor condition can cause reliability issues

---

4. Mechanical & Structural Evaluation

Spindle and Bearings

The grinding wheel spindle is one of the most expensive components. Ask about:

• Date of last bearing replacement
• Vibration analysis records (if available)
• Spindle runout measurements

Similarly, check for spindle chatter, oil stains, or abnormal noises.

Guideways and Ball Screws

Wear on linear guideways or ball screws will affect accuracy:

• Inspect lubrication records
• Look for excessive play
• Verify precision movement repeatability

---

5. Control System & Software

The CNC control is the “brain” of the machine:

• Confirm software version
• Ask if backup programs exist
• Check if the current operator understands programming

Legacy control systems can be supported, but software upgrades may be expensive.

---

6. Service History and Documentation

Preferred used machines usually come with:

• Operator manuals
• Maintenance logs
• Calibration certificates
• Test grind reports

Documentation reduces risk and often correlates with better machine maintenance.

---

7. Test Run and Measurement Verification

Before finalizing:

• Run a test part grind if possible
• Measure tooth profile, surface finish, and dimensional accuracy
• Note grinding wheel condition

If a test grind isn’t possible onsite, consider shipping the machine to a certified dealer for inspection.

---

8. Spare Parts Availability

Because Reishauer is a German manufacturer with global support, parts are generally available. Still verify:

• Availability of wheel spindles, motors, encoders
• Lead times
• After-sales support network in your region

If parts are hard to source locally, you may face extended downtime.

---

9. Total Cost of Ownership (TCO)

A used machine’s price is only one factor. Also budget for:

• Shipping / rigging / installation
• Leveling and alignment
• CNC training
• Grinding wheel stock
• Tooling and workholding

An inexpensive machine with high rehabilitation cost may not be a bargain.

---

10. Red Flags to Avoid

Be cautious if the seller cannot provide:

• Clear documentation
• Running condition
• Machine history
• Reason for selling

Machines sold “as-is” without inspection rights carry higher risk.

---

Summary Checklist Before Purchase

✔ Model confirmation and build year
✔ Full technical specifications verified
✔ Spindle & mechanical condition assessed
✔ CNC and software functionality confirmed
✔ Test parts and accuracy validation
✔ Documentation and maintenance logs
✔ Spare part & support availability
✔ Cost of rehabilitation and installation