b'People who run aluminum at lower rpm just weld the whole chunk of aluminum right onto the cutter.Up to Speed loaded ball bearings with obliqueone drop, Bryan said. After thou-contact that ensure strength and ro- sands of cycles, it gets to be a prob-tation precision of less than 0.01 mmlem eventually. This helps solve that sources. Mechanical speeders are(0.0004"). problem.driven by a machine spindle andBryanMachineServicesVRTEltools Titespot spindle speeders increase its speed as a fixed ratio.high-speed spindles have variable- are powered by a positive displace-Electric, air turbine and coolant- speed adjustment and utilize airment ball piston motor. Coupled to driven attachments are powered byturbines, which do the actual turn- a high-pressure coolant system, this their respective sources of energy. ing instead of the machine spindle.results in machining center spindle Themechanicaltypeutilizes a planetary gearbox to drive the speeder and convert every spindle rotation into a higher speed. Elec-tric models typically employ 350W, DC brushless motors to generate up to 80,000 rpm. Other kinds use compressed air or high-pressure coolant to drive a spindle. They all have benefits and best uses.Mechanical spindle speeders in-clude those made by OMG North America.These tried-and-true devices are built with high-quality bearings andBryan Machine Service OMG North Americagears, so they have a very posi- A cutaway of an air-driven spindle speeder is shown (left). Two planetary gearboxes increase tive drive-through gearing and aspindle speeds on units from OMG North America (right).very rugged construction, John-son said. The spindles feature an adjustablespeeds of as much as 45,000 rpm.The highest-speed models fea- built-in regulator to maintain spin- Titespotspeeders,whichare ture two planetary gears with ra- dle speed as the cutting load varies. available in common taper sizes, tios of 1-8 for high transmission andAs the cut gets heavier, Bryanoperate at 13.8 to 137.9 bar (200 to high power ratings. The speederssaid, then it supplies itself with2,000 psi)depending on the load. are available with shanks for all ma- more air to adjust to the load. The standard speeder delivers900 chine spindles and have the optionOperators adjust spring tensionrpm per 3.8 liters (1 gal.)of coolant of through-tool coolant to be sup- internally on the regulator via a but- flow. With a 37.9-lpm (10-gpm) cool-plied through a machine spindle. Aton on the side of the spindle. ant delivery system, this equates to spindle is supported by a set of pre- The unit also features an autocou- 9,000 rpm. But with the addition of pler that originally was designed fora modular 1-5 planetary gearbox, contributors a Haas vertical machining center.spindle speed increases to 4,500 Bryan Machine Service Inc. The coupler is adaptable to mostrpm per 3.8 liters of coolant flow. So 260-356-5530 CNC machines, including lathesthe same 37.9-lpm system now de-www.bryanmachine.com and grinders. When not in use, it islivers 45,000 rpm.closed on each side to seal it fromThe power has not changed, Eltool Corp. debris. An air wash feature blowsYoung said. We just generated 877-435-8665 away coolant before it can enter themore speed by shifting into fourth www.eltool.com spindle during the coupling. gear.OMG North America Anytool-changeablespin- Thespeedersalsocanbe 866-440-8519 dle gets a slight bit of coolant in itadapted to lathes and are available www.omgamerica.com every time it couples, even if it isin-line or as right-angle heads.CTE48MAY 2020Micromachining.indd 48 4/16/20 6:03 PM'