G&L Mill DRO Application

For Fulton Iron Works in St. Louis, MO.


Pictured to the right is a G&L Horizontal “T” type Boring Mill. The machine’s nameplate indicates it was built in 1947. Even as an old machine, we achieved a higher level of accuracy than expected by using the latest Heidenhain Linear Scales. Also included with this installation was the addition of the AMS spindle readout for G&L Boring Mills without a power draw bar. See the last picture on the bottom of this page for further details on this.


Due to customer’s request, we installed the Y-axis scale on the front of the column to greater enhance tool position accuracy. Notice the sheet metal chip guard along the headstock to deflect chips and coolant away from the reading head and scale assembly. It also protects the scale and reader head while loading the large parts on and off this machine.


Here the X-axis is installed on the outboard side of the machine table. We used the heavy duty Heidenhain “LB 302” for this axis as it’s travel exceeds the length of standard 10′ glass scale. Not pictured at this point is the heavy cover fabricated by the customer that doubles as a step to the machine table.


For this machine’s day to day use, the Heidenhain “PT 855” display was incorporated due to varied functionality. The display was mounted above analog instrumentation for convenience of the operator. The swivel base was also used to reduce the glare from the nearby wall of windows. Not pictured here is the “KT 130” touch probe incorporated for part position set-up.


Perhaps the most interesting aspect of this installation, is the new AMS spindle position readout for G&L Boring Mills. This unit incorporates a “draw string” type encoder device that attaches to the tapered roller bearing retainer located on the end of the spindle. This provides for true position and no back lash. It also eliminated modifications to the mechanics of the machine. This unit is available as just the measuring system or as the complete can cover assembly. It can be configured to work with “anyone’s” digital display.