Warner Swasey SC28 Retrofit with NUM CNC
MasterControls was contacted by a customer in the pump manufacturing industry. This customer had a Warner Swasey SC25 lathe with an extremely old control on it. They did not want to replace the machine due to its size and the cost of replacement. They were in need of a reliable CNC control that would give them more capabilities. They decided that MasterControls and the NUM control were a good fit for the machine upgrade. The customer additionally decided to do all the mechanical work themselves.
The WS SC28 control upgrade consisted of the following components:
Completely new electrical cabinet
• Power distribution
• Power supplies
• (2) Large isolation transformers for spindle and drives
• Interface relays
• CNC control
• Digital drive system- 2 axes
• Digital DC spindle drive
• IO system
New Motors
• Absolute feedback
• High resolution
• Cable assemblies
New Operator Station
• 15” Operator display/IPC with NEMA keypad
• Machine Tool Builder Panel (MTBP)
• Industrial mouse
• UPS power supply
• MPG- machine pulse generator
Reuse of rear electrical cabinet
• EtherCat IO drop to run machine IO terminated in the rear of enclosure
• Main safety contactor that dropped power to machine when CNC cabinet is open
• New turret brake supply
Special Machine Feature Needed:
Like many machines of this type, the SC28 was showing extreme wear in the last 12 inches of travel toward the spindle chuck. This wear typically happens because most of the machining by the customer had been done in this area over the years. The resulting wear consisted of a .040” taper progressing toward the spindle chuck. The customer was worried that they would have to spend a substantial amount of money rebuilding the machine.
Due to the flexibility of the NUM control, we were able to use the SAG compensation feature (2D compensation) and remove the taper in the machine. The compensation is done by making the Z axis a master and implementing a compensation table to correct in the X axis as the turret approaches the chuck. A bar was chucked in the machine and machined in order to see where the compensation needed to be applied and how much compensation.