KESSLER Spindle Repair on DMG CMX 1100 V

Bybmsserwis

KESSLER spindle overhaul on DMG CMX 1100 V (12,000 rpm, SK40)

  • Spindle manufacturer: KESSLER

  • Machine: DMG CMX 1100 V

  • Spindle speed: 12,000 rpm

  • Taper: SK40

The complete overhaul of the KESSLER spindle in our workshop restored factory precision and process stability to the DMG CMX 1100 V. We delivered a comprehensive service scope including bearing replacement, SK40 taper restoration, installation of a brand-new OEM drawbar assembly, sensor calibration, and replacement of all seals. Additionally, we supported the customer during self-installation of the spindle and helped eliminate the root cause of the previous coolant ingress. The service is covered by a 12-month warranty.

KESSLER spindle overhaul – DMG CMX 1100 V, SK40, 12,000 rpm

Diagnostics
and verification of the KESSLER spindle condition on DMG CMX 1100 V

Symptoms and initial diagnosis — KESSLER spindle on DMG CMX 1100 V:

  • elevated vibration noticeable across the entire speed range,
  • signs of overheating on the housing and a decline in surface finish after machining,
  • alarming noises at high speeds (up to 12,000 rpm) indicating bearing wear,
  • traces of coolant and contamination — the result of machine leaks leading to degradation of internal spindle components.

The initial assessment confirmed the need to replace precision spindle bearings and inspect the tool drawbar system. We also checked the bearing seats and evaluated the SK40 taper geometry to rule out defects that could increase runout and transmit vibration to toolholders.

Work scope — step by step
KESSLER spindle repair – DMG CMX 1100 V

1. Spindle disassembly and cleaning
We disassembled the KESSLER spindle at the service station, performed precision cleaning and inspection of bearing seats. We checked axial and radial alignment as well as the condition of seal grooves and lubrication/cooling channels.
2. Replacement of the complete spindle bearing set
We installed bearings matched to the loads and speeds typical for DMG CMX 1100 V (12 000 rpm). Assembly followed strict procedures: correct fits, preload, and clean-room handling.
3. SK40 taper restoration
We corrected taper geometry, removed burrs and corrosion marks, restoring the mating surface to spec. Result: secure tool clamping and improved radial runout.
4. Drawbar replacement and clamping-force calibration
We installed a brand-new OEM drawbar assembly dedicated to this KESSLER spindle and then measured and calibrated the clamping force for SK40, ensuring reliable toolholding and consistent tool changes.
5. Dynamic spindle balancing
After assembly we performed dynamic balancing to a level suitable for 12 000 rpm (practice: accuracy class 0.4G), minimizing vibration and extending bearing life.
6. Sensor calibration and tests
We calibrated speed/position sensors, verified signals and alarm thresholds to ensure correct cooperation with the DMG CMX 1100 V control system.
7. Final inspection and run-up tests
We conducted controlled startups, measured temperature, noise and vibration across the full speed range, and verified radial and axial runout under load after thermal stabilization.
Clamping-force calibration – KESSLER spindle, DMG CMX 1100 V, SK40 taper Complete KESSLER spindle overhaul – DMG CMX 1100 V, 12,000 rpm, SK40

Service results
KESSLER spindle – DMG CMX 1100 V

  • Significant vibration reduction and stable operation across the full speed range.
  • Restored machining precision — improved surface finish and dimensional accuracy.
  • Correct tool clamping force — secure SK40 toolholding and longer tool life.
  • Resistance to coolant ingress thanks to new seals and improved coolant-system integrity.

On-site customer support
installation and leak elimination

The customer chose to install the spindle independently at their facility. We provided full technical support — detailed installation guidelines, a run-in and warm-up procedure, and consultations to eliminate coolant-system leaks to prevent recurrence of flooding.

Tool clamping-force measurement – KESSLER spindle, DMG CMX 1100 V, SK40 taper KESSLER spindle service – DMG CMX 1100 V, 12,000 rpm, SK40

Post-service recommendations
KESSLER spindle – DMG CMX 1100 V

  • Regularly inspect the machine’s coolant system and seals.
  • Follow warm-up recommendations before high-speed operation.
  • Monitor vibration and temperature — early response greatly extends bearing life.
  • Keep the SK40 taper and toolholders clean (debris may worsen runout and cause micro-damage).

Warranty and responsibility
12 months of service coverage

Our KESSLER spindle overhaul is covered by a 12-month service warranty. The warranty covers workmanship and the parts used, in line with the service protocol provided to the customer.

Summary
stability, accuracy, operational safety

The overhaul restored the KESSLER spindle on the DMG CMX 1100 V to full performance and accuracy required for both serial and precision production. A comprehensive approach — from diagnostics through bearing replacement and SK40 taper restoration to sensor calibration and new seals — delivered a lasting result and safe operation. Additional support in eliminating the leak source minimizes the risk of recurrence.

Frequently asked questions
about KESSLER spindle overhaul – DMG CMX 1100 V

Typically from several to a dozen business days — depending on parts availability (especially an original drawbar assembly) and the scope of damage found after disassembly.
Yes. We recommend a gradual warm-up and stepwise increase of speed according to the supplied run-in sheet. This stabilizes the bearing system and improves durability in DMG CMX 1100 V operation.
Most common causes include: contaminated or overly aggressive coolant, leaks leading to flooding, incorrect tool-change procedures, lack of SK40 taper/toolholder maintenance, and running at high speeds without proper warm-up.
For critical items — such as the drawbar assembly and components affecting safety and accuracy — we use original OEM parts. Bearings are selected to match the spindle’s operating parameters per KESSLER/DMG CMX 1100 V specifications.
Warning signs include increasing vibration and noise, higher operating temperatures, poorer surface finish, control system alarms, and reduced clamping force with the SK40 taper. Any of these require prompt checks to avoid more serious damage.

Express KESSLER spindle overhaul
DMG CMX 1100 V – fast and precise

Do you need a KESSLER spindle overhaul or service of another brand on a DMG CMX 1100 V? Contact us — we’ll provide rapid diagnostics, propose the optimal scope of work, and restore your machine to full precision.

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