Microfinishing / Superfinishing of Balls, Cups and Discs

The Sphero is the Thielenhaus platform for flexible machining of spherical parts, providing not only optimal surface results but also perfect form. A swivel-mounted and MicroSens force-controlled tool spindle enables precision-finishing of cups and balls from all sides.

Depending your preferences a polishing process can be integrated to succeed Microfinish / Superfinish.


Precision surface finishing / polishing of acetabular cups and modular heads for artificial hip implants

The Sphero is ideal for creating optimum surface finish and spherical geometry for orthopaedic hip implant components, including femoral cups and heads.

Microfinishing the surfaces of these ceramic or metallic parts minimizes the surface roughness to Ra < 0.02 µm and can simultaneously improve roundness to <2 µm, thus ensuring a better ball-socket fit and further reducing friction and wear.

The machine can be equipped with the necessary tooling to finish both ceramic and metallic (ex: Cobalt-Chromium) components, thus making it suitable for all types of hard-on-hard and hard-on-soft implant applications, with or without liners. 


Machine Data:

Working area diameter: 75 mm

Work piece spindle: 0-2000¯1

Tool spindle: 1500 - 15000¯1

Precision Tool Changer: up to 10 tools



  • Workpiece interchangeability across small or large production series without time-consuming categorization: the Microfinish unit is equipped with MicroSens force-control technology with first-cut detection and stone wear compensation. This technology, along with rigid machine structure, a precision spindle and special tooling (can include CBN or diamond abrasives), ensures extremely high accuracy and repeatability in the results and prevents operator errors. 
  • Flexible finishing of balls, cups and flat surfaces: the machine can be supplied with multiple tooling and chucking systems so that manufacturers can microfinish convex / spherical surfaces as well as concave counterpieces. Even flat surfaces can be finished with < 1 µm flatness.
  • User-friendly machine design: the most compact machine of its type, the vertical design allows for easy access for operators and service technicians.
  • Optional addition of gauging systems or various automatic loading systems


Sphero in the news: read the November 2014 article in the UK-based Grinding & Surface Finishing Magazine >>Download Article (PDF)


  • Arbeitsraum Kugelfinishmaschine EndoStar
  • Feinstbearbeitung von Kugeln - Oberfläche und Geometrie
EndoStar Prospekt

Produkt Flyer (PDF)

DE     EN





(ball and cup)

2,0 µm

Ra ≤ 0,03 µm

Shift ball

3,0 µm

Ra ≤ 0,03 µm

Excentric shafts

1,5 µm

Ra ≤ 0,05 µm

Spherical washers

2,0 µm

Ra ≤ 0,03 µm

Slide shoe

2,5 µm

Ra ≤ 0,08 µm

Coupling balls
(for wheel suspension and steering)

4,0 µm

Ra ≤ 0,04 µm