What is a servo press?

A servo press uses servo motors for precise force and position control during forming operations.

How do I calculate servo press tonnage?

Use our free tonnage calculator at servopress.club/tonnage-calculator.html

Used Servo Press Inspection: 12-Point Checklist Before You Buy

admin

Used servo presses can offer excellent value, but they also carry hidden risks. This 12-point inspection checklist helps you evaluate a used press before purchase.

## Before the Site Visit

1. Request maintenance records: ask for the last 3 years of maintenance logs. Look for recurring faults, major repairs, and whether scheduled maintenance was performed on time.

2. Check the drive firmware version: older firmware may have known bugs. Ask for the drive model and firmware version, then check the manufacturer release notes.

3. Verify the encoder type: absolute encoders are standard on modern servo presses. If the press uses incremental encoders, homing is required after every power cycle - a significant operational disadvantage.

## Mechanical Inspection (On-Site)

4. Gib clearance: measure with a dial indicator. Clearance above 0.15mm indicates worn gibs that need replacement (budget $2,000-$8,000 depending on press size).

5. Slide parallelism: place a precision level on the slide at TDC and BDC. Difference above 0.05mm per 300mm indicates frame distortion from overloading.

6. Crankshaft end play: on eccentric-drive servo presses, check crankshaft axial play. Above 0.1mm indicates worn thrust bearings.

7. Noise during slow-speed run: run the press at 5 SPM and listen for knocking, grinding, or irregular sounds. Knocking at BDC indicates worn connecting rod bearings.

## Electrical Inspection

8. Drive condition: check the drive cooling fans (replace every 3-5 years), capacitor age (replace every 7-10 years), and look for signs of overheating (discoloration, burnt smell).

9. Motor insulation: measure motor winding insulation resistance with a megohmmeter at 500V. Should be above 100 megaohm. Below 10 megaohm indicates moisture or winding damage.

10. Encoder battery: check the encoder battery voltage. Replace if below 3.2V. Budget for replacement batteries ($20-$50 each, typically 2-4 per press).

## Operational Test

11. BDC repeatability test: run 20 strokes at production speed and log the BDC position. Standard deviation above 0.02mm indicates worn mechanical components or drive tuning issues.

12. Overload test: run 3 strokes at 110% of rated tonnage (if the press has a tonnage monitor). The press should complete the strokes without fault. Any fault at 110% indicates the press is already running near its limit.

## Price Negotiation Points

Use inspection findings to negotiate:
- Worn gibs: deduct $3,000-$8,000
- Drive capacitors due for replacement: deduct $2,000-$5,000
- Motor insulation below 50 megaohm: deduct $5,000-$15,000 (motor rewind or replacement)
- No maintenance records: deduct 10-15% from asking price

pete_retrofit

I'd add a 13th point: run the press empty at full speed for 30 minutes and monitor motor temperature. A healthy press should stabilize below 60?C ambient + 40?C rise = 100?C. If it's climbing past that on air strokes, something is wrong —usually gib binding or counterbalance issues.

carlos_stamping

Negotiation tip: use the inspection findings to negotiate price. Every issue you document is a bargaining chip. We bought a used 200T with worn gibs and a noisy gearbox. Used the inspection report to negotiate $25K off the asking price —more than enough to cover the repairs.