Fellows 50-12 Hydrostroke Gear Shaping Machine

This machine was originally a fully mechanical machine with change gears for the indexing and Fellows proprietary controls.  We have done a complete recontrol of the machine and conversion to a full 5 axis plus spindle CNC control. All the mechanical systems were removed and the axes drive mechanisms were redesigned to adapt servo motors as close as possible to the driving screws. In addition we installed a entirely new hydraulic system for the machine.

The Recontrol Project
Prior to the start of the recontrol project the machine was configured with the original Fellows control system, and hydraulic unit. Both were showing significant signs of age, and had become a chronic maintenance headache. Replacement parts were no longer available easily, and finding qualified personnel to repair the equipment was equally difficult to achieve. Due to the critical need for this machine, the customer could not afford a significant amount of downtime. Machine Tool Builders was asked to perform a rather complex controls upgrade in the field, with a very short lead time, and an even shorter machine downtime.

As part of the recontrol project Machine Tool Builders designed and manufactured a completely new electrical cabinet and hydraulic unit at our facility. We engineered and manufactured the mechanical adaptations required to convert the machine from a mechanical shaper into a fully numerically controlled machine. All these pre-manufactured items were sent to the customers site as a kit, prior to the actual installation beginning.

Almost all the work was done at the customers site. Some of the more extensive mechanical work was sent back to our shop for the modifications, then returned to the customers plant.

New Hydraulic System
The original hydraulic system had been a maintenance nightmare for many years. Chronic pressure and volume problems plagued the machine on a daily basis. With few or no replacement parts in the customers inventory, swapping components for diagnosis was impossible. To compound the problem, many of the components were no longer manufactured so finding replacement parts had become almost a full time job.

The new hydraulic system Machine Tool Builders designed and delivered, contained all new components of the latest design, with full warranties and readily available through local vendors, thus assuring many years of trouble free operation.

New Electrical Cabinet
The original electrical cabinet was removed in it’s entirety and replaced with a totally new one, designed and manufactured at our facility. Much of the cabling to and from the machine was replaced in the process.

The new control system was centered around a NUM Power 1040 CNC. We chose Indramat Ecodrive servos coupled with Indramat MHD motors and SSI encoders because of their performance and reliability. This combination of controls was extremely cost efficient, offered short lead times and was very easy to implement, which translated into savings for the customer.

Mechanical Conversion
Since the original machine was mainly mechanical, there was a significant amount of mechanical modification required to complete the CNC conversion. Among the most extensive modifications was the addition of a servo motor, ball screw and automatic clamping system for the stroke length adjustment. Additional mechanical changes included installing servo motors to the stroke elevation, radial axis, stroke drive, table and cutter rotation.