THREE AXIS IOL AIR BEARING MILL DLM SERIES II Features Description Operation Programming Control System Tooling Automation Option Specifications

This DAC machine is a 3-axis vertical mill with air bearing spindle(s) particularly designed for the milling of intraocular lens haptics as well as other plastic and nonferrous materials. Both one and two spindle versions are available.

The machine is based on a granite surface plate for accuracy and stability. The surface plate is mounted on vibration isolators on a welded steel frame. The controller and all electronics are housed inside the machine base.

The X and Y ways are of the cross roller type, driven by zero backlash ball screws. Rotary encoders are employed to provide the fine resolution necessary for high accuracy and the blending of interpolated surfaces.

The air bearing, high frequency, air cooled milling spindle is mounted on the vertical Z axis which also uses cross roller bearing ways and ball screw feed. A rotary encoder is used as a feedback system for the DC servo motor.

Either one or two spindles may be provided on a single slide or two spindles may be mounted on separate slides to allow each spindle to be independently programmed and controlled. 

Table travel is 6" x 12". The 14" x 14" work area allows parts to be mounted in a "gang" fixture or separately mounted for "one at a time" processing.

The two spindle, two slide version allows simultaneous milling under both spindles with subsequent drilling under both spindles or alternate milling and drilling. Spindle spacing amy be specified to match tolling.

Important features are the fine resolution (less than 1 micron) and "continuous velocity" milling. Both features are necessary to allow the continuous smooth blending of arcs, line segments and tangents required to provide mark free blending of haptic contours.

The machine also provides for 3-axis (helical) interpolation to allow the tool to be translated vertically in coordination with the X-Y table movement.

The machine may be provided either with manual wrench operated collets (manual tool change) or automatic centrifugal collets. 

Programs may be prepared on the on-board computer, then transferred to the DAC IOL Mill on a 3.5" floppy disk, or down-loaded from a computer via an RS232 port.

The tool path may be determined by manual calculations, or a commercial CAD system such as Mac Auto or Auto Cad may be used to produce the part program. Tool radius compensation is a standard feature of the controller.

The program for coordination of the third axis (the spindle vertical travel) with the X-Y motion of the table can be derived automatically from the CAD defined geometry of the lens cross-section.

A graphic presentation of the lens is presented on the CRT. "Menus" guide the user through machine set-up, calibration and operation. Full "on-screen" editing is available for program modification.

Machining parameters such a spindle speed, in-feed rate, peck cycles, table feed rates and auxiliary functions are all controlled by the part program. 

All DAC IOL Mills employ the DAC Digital Motion Control (DMC) system.  It is housed in the Pentium computer, mounted with the servo amplifiers, in the base of the machine behind hinged doors for easy access.

Each axis is driven by a servo motor with rotary encoder feedback and is controlled by the Digital Signal Processor.

Special software and high speed math processor enable the DAC IOL Mill to calculate in real time the correct path for milling the haptic contour. Pauses between blocks of data are thereby eliminated which produces very smooth and nick-free haptics.

Auxiliary functions such as actuating lights, vacuums, air blasts, etc. can be added by the user by utilizing the several available "M" functions.

The 14" x 14" steel work table top may be removed from the machine to facilitate the addition of jigs, fixtures and other tooling items.

The machine may be equipped with a single position air operated collet closer, or gang fixtures of the user's design may be attached to the work table.

Special software provides that fixtures with multiple work positions may be "mapped" and stored in memory to allow accurate registration of repeated patterns. 

Auto Loading -

DAC has developed and produced auto loaders for both blank buttons and blocked parts. These cartridge-to-cartridge systems are ideal for automating high volume manufacturing facilities.

Slides:

All slides are D.C. motor/zero backlash ball screw driven with rotary encoder feedback.

	X	Y	Z
Travel:	12" (304mm)	6" (152mm)	2" (51mm)
Resolution:	.00001" (0.25 micron)	.00001" (0.25 micron)	.0001" (2.5 micron)
Traverse Rate:	200 IPM (5m/min)	200 IPM (5m/min)	200 IPM (5m/min)

 

Single Axis Accuracy:

Incremental Overall

+/- 0.00008" (2 microns) +/- 0.0004" (10 microns)

 

Spindle:

15,000 to 160,000 RPM air bearing, air cooled, high frequency, synchronous motor. Manual wrench collet 1/8" (3.2mm) is standard. Centrifugal or automatic air operated collet available. Air blow off jets are provided adjacent to tool tip.

 

Installation Data

Power:	208, 220, 230, 240 VAC, 1 phase, 50/60 Hz, 20 Amps
Spindle Cooling Air:	2.75 CFM @ 80 PSIG (4.7m3/Hr. @ 5.6 Kg/cm2)
Temperature:	68 to 74 Degrees Fahrenheit (20 to 23.3 degrees C)
Vacuum:	User Furnished 1.25" (3.2 cm) Diameter Manifold
Floor Space:	36" X 44" X 60" high (914mm X 1118mm X 1524mm)
Floor Weight:	1600# (726Kg). Shipping - 2000# (908 Kg)