Rebuild & Retrofit – Grinding Machines

Marathon Machine Tools offers CNC retrofit packages both for DANOBAT and other major brand grinding machines. We will replace obsolete old CNC controls with new FANUC control packages or state-of-the-art NCT control packages according to the requirements of our customers. Our services include the development of new PLCs and HMIs for machine specific grinding cycles.



Every grinding machine retrofit is unique and therefore Marathon develops a case study with the customer for every rebuild and retrofit project. The case study includes the evaluation of the need of the customer, offers technology upgrade solutions and also takes the financial feasibility into consideration. According to budgetary concerns we offer either FANUC or NCT retrofit packages.

Danobat – Overbeck IR-400 internal grinder

The IR-400 internal grinder is a popular grinding machine and several 100s of them serving our customers well since the early 1980s. They are widely used in the canning industry, but also as ball grinders or in the aerospace and medical device manufacturing.



The original machine was designed with hydraulic axis slides and a type of control that was revolutionary in its time, but it is not keeping up with today’s technology anymore.
We rebuild these IR-400 machines using new precision ball screw servo drives on the X and Z axes, and upgrade the swiveling B-axis utilizing modern servo axis technology as well.
The FANUC 0-iTF control is paired with digital FANUC servo and spindle drives and motors. The whole electric cabinet is replaced with new components and cable/wires eliminating every old and questionable part not leaving any chance of failure.

The machine is equipped with new electronic technology, including up to date grinding cycles with user friendly HMIs. Machine accuracy will be increased by utilizing ne w precision servo ball screw technology replacing old hydraulic drives.

Hoefler Helix-400 Gear Grinding Machine

Over a period of 10 years almost 400 of these machines have been shipped to customers around the world. Gear manufacturers in the aviation and commercial vehicle industry as well as gear grinding companies hold the HELIX in high regard as an indestructible, flexible, and expandable basic machine for continuous operation – and as an investment with a very fast return.



This machine from 1990s received a complete electronic retrofit using the NCT-201 control and drive/motor package. All cables and wires were replaced and a fast EtherCat communication system installed between control and drives.

Schaudt ZX 1 Cylindrical Grinder

This 1995 Schaudt cylinfrical grinder hes been retrofitted with new NCT-201 19” touch screen CNC control, NCT drives and motors and EtherCat communication system. Mechanical Rebuild was not part of this project.