Modul ZFWZ800/3 Gear Hobbing Machine

Full Remanufacture and Conversion to 4 Axes and 1 Spindle
 
This machine was originally a fully mechanical machine with change gears for the index and differential and equipped with unreliable East German controls. We have done a complete machine remanufacture and conversion to 4 axis and 1 spindle under CNC control. All the mechanical change gears were removed, all gear boxes, extraneous drive shafts, pulleys, motors etc were removed. The axes drive mechanisms were redesigned to adapt servo motors as close as possible to the driving screws.

The Arrival
When the machine arrived at our facility, it was in very bad shape. It had been out of service for a number of years because it had not been working reliably. So had parts cannibalized, and the machine was mess of dirt, grime and oil.

The Remanufacture Process
The remanufacture process took approximately 10 months to complete and went through many different phases, to numerous to list here. But here is a few photos taken along the way to show the extent and attention to detail that goes into every MTB remanufacture and rebuild project.

The machine first was totally disassembled and thoroughly cleaned. All the guideways needed to be refinished, and the machine alignments checked per the DIN ISO 6545 acceptance criteria for gear hobbing machines. All the parts required inspection for tolerance, wear and feasibility of reuse. 

Each sub-assembly of the machine was meticulously disassembled, cleaned, inspected and rebuilt back to the OEM specifications. All the bearings and seals were replaced, bearing surfaces re-scraped, way covers, wipers and bellows replaced. New ballscrews were installed, the drive trains were shortened and changed to reduce as much lash as possible, internal gear train modifications were made to simplify and improve the designs.   

The machine reassembly process was done in the proper sequence and with a very high emphasis on detail. All the major assemblies were rebuilt off the machine. Once placed on the machine, they had to be checked for accuracy and fit on the machine itself. Each major assembly was installed and tested to verify it's functionality. 

An entirely new hydraulic and lubrication system was installed on the machine. All the fluid and pneumatic hoses were replaced, many pipes were replaced, all the lubrication metering valves and blocks were replaced. All the fluid power controls such as valves, pressure and flow regulators, flow and pressure feedback devices etc were replaced with new.

Once fully assembled the machine was setup and prepared to hob the first test pieces. Test cutting was done on a variety of parts, both left and right hand in order to very that the machine was indeed accurate and capable of holding the workpiece tolerances.

As the machine neared completion, all the guarding and safety devices were installed and tested. An entirely new electrical enclosure was designed and manufactured. We installed a new Fanuc 0i-D CNC with Fanuc Alpha HVi series drives and motors were installed on the machine. Our standard conversational programs were loaded to make the data entry process easy and fast for the operator.