Holemaking

Workholding

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Current Hole Making Projects

Flexibilty - N/C controlled 4 axis, tapping system (two spindle axis - two feed axis) Features Zagar, standard, ball-screw actuated, quill feed units. Tapping opposing ends of steel shaft (tubing) Programmable stations are capable of left or right hand threads in decimal or metric pitch. Thirty sub-routines (programs for specific tap sizes and shaft lengths) are stored in the memory of each tap station's controller. The tapping stations and hydraulic, self-centering vises are individually mounted on sub-slide bases (saddles) using THK linear bearings at the four corners of each saddle.

Two THK, precision linear rails run the length of the machine table. Positions of the tap stations and vises are adjusted to datum points using lined precision holes and set-up pins. Each stored, programmed tap cycle relates to a specific work piece length (from 6" to 30") and tap size. Tooling included quick-change, radial floating, tap holders. Vises included quick-change jaws, adjustable end stops, and fool proofing (taps could not crash into jaws with no work piece in the fixture).

Wheel hub, lug hole, drilling system with robotic (Fanucmate 100i) material handling that included automatic, steel belt, entry and exit conveyors. Statistically controlled process (1.67 CPK): Drilled, finished sized, chamfered, and spot faced a five hole pattern (.625" dia. nominal) from the front side of the hub. The drill station consisted of a ball-screw actuated, box way, precision slide and 50 HP spindle motor. The N/C controlled drilling cycle featured a two stage cycle.

During this cycle the RPM and feed rate are reduced after the drills break thru the back-side of the drilled section and before the spot facing diameter of the cutting tool engage the part. Spot facing also includes a timed dwell at full depth. The amount of dwell time is programmable in milliseconds. The complete drill, chamfer, spot-face cycle is completed in less than 5 seconds. An N/C controlled back-chamfering operation is performed by the opposite five spindle station. Total cycle time for machining the required five hole pattern from both sides, is less than seven seconds.

Capability - Zagar, precision, multiple spindle head with tri-plex, spindle ball-bearings and HSK shank, quick-change, hydraulic tool holders. The single pass hole drilling and finishing process produced consistent holes within a .0002 - .0003" diameter deviation and .001" deviation on position. The system also featured a fully integrated, filtered coolant system and chip conveyor.

Automotive die casting. Requirements - Tapping or reaming cast holes in family of upper and lower, brake valve, body castings prior to processing to robot loaded, dual spindle, CNC turning center. The goal was to tap the subject castings from multiple directions at two stations in the less than the 25 second cycle time of the turning machine. Material handling was manual and the door on the enclosure started the machine to minimize cycle time.

The multiple spindle tapping stations at the rear of the machine featured individual lead screw tapping spindles for tapping a combination of 18 or 20 pitch threads. All taps were non-cutting style, form taps. In turn, each spindle pattern featured a composite of all the required patterns. Changeover between parts within the family of castings only required the individual taps to be changed over to the spindles for the required hole pattern. All tool holders were quick release, Zagar, z-lock standards. The work holding fixtures were supplied on sub-bases incorporating a ball-lock locating system to enable quick-changeover of fixture assemblies.

The forward station, nearer to the operator, featured a rotary index table and two, single spindle, ball screw actuated, CNC controlled, Zagar MQ150, quill feed units. Each unit rigid tapped either a 1/4-18, 3/8-18, or 1/2-14 NPT pipe tap into tapered, cored bosses on the castings. Several styles of the castings required tapered reaming of the same cores. The programmed units enable quick change over between tapping pitch and the required stroke length to accurately maintain the gage dimension of the pipe tapped holes.

Quick-release tool holders made it easy to change the taps. A radial float feature in the tool holders kept the taps (and reamers) true to the center-line of the cast cores. Fixturing featured ball-lock locating pins for quick-change of each different casting's fixture sub-assembly. The machine system operates on an around the clock, seven day a week basis.

Industrial lighting, die cast housing. Requirements - Drill and tap multiple hole patterns from three sides of subject casting. A 17 hole pattern is drilled down within the deep cavity of the casting. The 17 spindle head shown in the adjacent photo featured extended spindles and adjustable length tooling at each spindle position. The adjustable tool holders enabled pre-setting an extra set of cutting tools off-line from the machine. Concerning fixturing, the deep cavity casting is loaded over an extended set of renew-able drill bushings. Clamping is hydraulic and automatic. All three stations cycle at the same time. Cycle time for a completed part is <10 seconds.

The two side stations on this machine feature ball screw actuated, CNC controlled, Zagar MQ150 units. These CNC, 2 axis stations are applied to enable drilling and tapping (2) 1/2-13 holes in one pass using a combination drill / tap tool known as a drap. One station features a multiple spindle head that also drills two additional holes into the side of the casting. These CNC controlled stations advance the tooling at the required drilling feeds and speeds and then changes over to an N/C rigid tapping cycle to tap the holes.

The time and cost savings of drill / tap tooling (draps) is a productive and efficient option when incorporating fully programmable, machine stations. In turn, the programmed stations readily adapt for new operations.

Large castings - High volume hole production. This project involved a large aluminum die casting with a high number of tapped holes in two sides of the parts. The castings came to the machined with all holes either cast or drilled in the ready to be tapped condition. Both stations featured Zagar, gearless, crank driven, multiple spindle heads with individual lead screws at each spindle position.

The gearless drive design assures long term production without back-lash developing as gear teeth and universal joints wear from the demanding loads of constantly reversing tapping operation. There are literally neither gears nor universal joints in Zagar multiple spindle stations. The drive crank section of any individual spindle is the same size as the entire spindle diameter. In turn, long term, efficient production tapping is assured because of the inherent 1 to 1 drive ratio of crank driven heads and a true 1 to 1 ratio of tap rotation to pitch feed.

Crank driven, gearless, drilling and tapping heads in standard sizes from 3" square to 32" X 60" rectangular. Standard heads and work holding fixtures are adaptable to any drill press or production unit. The number of holes machined (working spindles) by a specific head is limited only by the size of the head and the horse power and thrust needed to machine the hole pattern in one pass. In turn, the Zagar, crank driven, gearless drive design enables closer spindle to spindle center distances than any other multiple spindle drive design in industry. We always welcome the chance to propose our multiple spindle tooling packages, production units, and machinery for you to consider as a high capacity, cost effective solution for your hole making needs.