b'\x1b\x1a\x19 \x1f\x18\x1d\x17\x16Machine TechnologyMAGNETS SAVE SPINDLESBy William Leventon New England sales manager for GFidea is to halt the machine before Machining Solutions LLC, Lincoln- the spindle moves far enough to Aprotectionsystemshire, Illinois. If something is notbreak, as illustrated below.spindle based on magnetic force couldcorrect and the machine makes anThe system normally activates exert a pull on part manufactur- unexpected move, it could damagewhen a machine is operating in a ers experiencing costly machinethe spindle. setup or safety mode that lowers crashes. Preventing damage caused bythe maximum feed rate.If a collision occurs during heavy- collisions is the aim of the MachineTypically, youd have the system duty cutting, a machine spindleand Spindle Protection system de- on during the testing or prove-out can be subjected to tons of force.veloped by GFMS. The self-con- phase of your new program or pro-Besides breaking a spindle, a crashtained MSP system relies on per- cess, Payva said. Once you have can damage a tool and workpiecemanent magnets in the spindlerun it once or twice and feel con-A crash involving a machine spindle (left) can cause costly damage and downtime. The MSP system, however, allows a spindle to deflect after a collision, giving the system extra time and distance to take emergency braking action before a spindle breaks. V is the linear spindle velocity during a machining operation. Breaking distance is the amount of spindle movement after a collision that causes breakage.GF Machining Solutionsand result in significant machinehousing. During standard machin- fident about it, the risk decreases downtime. ing operations, the strong magnetssubstantially. Then you can turn the The chances of a collision arehold the spindle in position. In thesystem off, and the machine would greater than normal during theevent of a collision that generatesgo back to its max feed rate.initial phases of a machining pro- sufficient force, however, the mag- However,someshopsalways cess. At these times, crashes cannets disengage, allowing the spin- leave the system on for constant be caused by setup mistakes anddle to deflect either to the side orprotection, he said, at the cost of a programming errors in tests of newinto the machines z-axis housing. Atsmall amount of the feed rate they CNC programs. the very outset, he explained, thisotherwise could achieve.Programs for CNC mills are madedisengagement is detected by loca- If a collision occurs, the system up of thousands of instructions, andtion sensors that trigger emergencycan reduce the resulting force on a there is a high risk of something notbraking action within nanoseconds,spindle by 90%, according to GFMS. being perfect, said Dante Payva,bringing the machine to a stop. TheThe system protects spindles in all 14APRIL 2020 MachineTech.indd 14 3/16/20 11:19 AM'