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

Slide adjustment after tooling change - procedure?

jim_apps

Every time we change tooling, the slide adjustment seems off. What's the proper procedure for re-adjusting after a die change?

**Before You Start
**
- Confirm new die shut height from die drawing
- Check press stroke and BDC position
- Verify slide adjustment range (typically ?25-50mm from nominal)

**Calculate Required Slide Position
**
```
Slide position = Press BDC - Die shut height - Bolster plate thickness
```

Example: Press BDC = 0mm, die shut height = 285mm, bolster = 100mm
Required slide position = 0 - 285 - 100 = -385mm (385mm above BDC)

**Manual Slide Adjustment
**
1. Jog press to TDC (top dead center)
2. Engage slide adjustment mode on HMI (usually under Setup > Slide Adjust)
3. Enter target slide position or use +/- jog buttons
4. Adjustment speed: use slow mode (1mm increments) for final positioning
5. Lock slide adjustment when complete

**Verify with Test Stroke**

1. Install die in press (do not clamp yet)
2. Run one slow test stroke at 10% speed
3. Check die contact —slide should contact die at BDC with 0.1-0.3mm clearance before clamping
4. If die contacts before BDC: raise slide (increase shut height)
5. If gap at BDC: lower slide (decrease shut height)

**Tonnage Check
**
After clamping die:
1. Run 3-5 strokes at production speed
2. Monitor peak tonnage on press display
3. Acceptable range: 60-80% of press rated tonnage for normal production
4. Above 90%: check die alignment, lubrication, material thickness

**Common Mistakes**

- Forgetting to account for bolster plate thickness
- Adjusting slide while press is at BDC (always adjust at TDC)
- Not re-checking after thermal expansion (first 30 min of production)

pressroom_tom

Operator shortcut that actually works: after changing the die, run 5 strokes at reduced speed (10 SPM) with no material. Watch the tonnage monitor —it should show near-zero force. If you see any force reading, the shut height is too low and the die is touching. Adjust up 0.1mm at a time until the force reading is zero, then load material.

toolndye_dave

Always re-check shut height after the press warms up. I set up a die perfectly on Monday morning, came back after lunch and parts were 0.03mm oversize. Thermal expansion had changed BDC by 0.04mm. Now I do a rough setup cold, run 200 parts, then do the final adjustment once the press is at operating temperature.

carlos_mx

toolndye_dave nailed it with the thermal expansion point. We track this on our 250T and the BDC shift from cold to operating temp is consistently 0.03-0.05mm. On a progressive die that is running tight clearances, that is the difference between good parts and scrap.

One thing I would add to the procedure: after you set shut height, check your tonnage signature on the first 20 hits and compare it to the last run with that die. If the peak force is more than 5% different, something is off — could be shut height, could be material thickness variation, could be a worn punch. The force curve does not lie.

Also, if you are running a servo press with programmable BDC, do not just copy the old program. Measure the actual die shut height with a gauge block and set BDC from that measurement. I have seen guys copy a program from die A to die B and wonder why parts are bad — the programs had different BDC offsets baked in from previous adjustments that nobody documented.

raj_pm

Something specific to servo presses that gets overlooked during die changes — don't just adjust the mechanical shut height. Most servo presses have an electronic BDC offset parameter (on Komatsu it's in the recipe, on Aida it's the "slide adjust" screen). The mechanical adjustment gets you in the ballpark, but the electronic offset is where you do your fine tuning — 0.01mm resolution vs the 0.05mm you can realistically get with the mechanical adjuster.

The procedure I use: mechanical adjust to within 0.1mm of target, lock it down, then use the electronic offset for the last bit. This way the mechanical system isn't fighting the servo on every stroke. I've seen setups where someone cranked the mechanical adjuster way off and then compensated with a huge electronic offset — the motor was working 15% harder than it needed to on every cycle. Energy waste and extra heat.

The other thing — save your recipe BEFORE you start adjusting for the new die. I know it sounds obvious but I've watched guys overwrite a good recipe because they forgot to save-as first. On our Komatsu the recipe stores BDC position, speed profile, tonnage limits, everything. We label them by die number and date. When that die comes back in 3 months, you load the recipe and you're running parts in 10 minutes instead of 45.