GENERATORS: WORKHORSE TURNED SHOW PONY WITH AMAZING TRICKS

By Judith Lee

Already recognized as the workhorse of the larger optical laboratory, the generator has been enhanced by manufacturers who have brought new technology to their stable of products. Transformed into a show pony with an array of new tricks, generators are now performing in ways that make lenses faster, prevent production problems, handle more complex lens designs and fit into smaller lab configurations.

“Today’s generators can cut everything from traditional/toric work like flat tops and trifocals to freeform progressives and everything in between. The latest generators come with an on-board verification system so freeform jobs can be simulated before they are cut and quality can be validated in both Rx tolerance and cosmetic tolerance,” noted Kevin Cross of Schneider Optical Machines USA.

Following is an overview of capabilities and features that are likely to be news to lab owners and managers.

1. FASTER

OptoTech Optical Machinery, Inc. has recently released a new, ultra-fast automation production cell. “The smartLAB ultraline is the fastest cell for digital lens production available in the market,” said COO Jeff Grumbling. “The generator’s output of up to 150 jobs/hour is thanks to powerful, direct-driven async motors combined with an optimized loading unit and a high resolution CNC-controller.”

Schneider also has a fast generator, the HSC Modulo XT, powered by a proprietary 4G motor.

“The XT generator operates at speeds never before possible without sacrificing surface quality,” noted Cross. He added that automated calibration is another advantage that saves the lab time and gets the machine into production faster.

Satisloh is raising the bar with their high-volume flagship generator set, with the introduction of the VFT-orbit 2. The fully-automated VFT-orbit 2 is the world’s fastest, easiest to service and most robust generator. Several innovations make the VFT-orbit 2 incredibly fast. A high performance milling spindle for cribbing and rough surfacing improves speed and throughput up to 20 percent. Also the proprietary milling tool interface for the 14-tooth cutter enables 60 percent higher revolution speed and guarantees unsurpassed accuracy and stiffness, reduced run-out and extended tool life.

2. IT’S TWINS!

Speed is not just a function of fast motors. Some new designs use “twin technology” to get more work done faster.

At the heart of OptoTech’ smartLAB are ESM Twin-A and the FLASH Twin-A, which separate the milling and turning process. The ESM Twin-A is the milling unit, equipped with two spindles to simultaneously process two digital lenses. The digital surfacing-turning machine, Flash Twin-A, uses two Fast Tools to simultaneously process two digital lenses.

“Considerably increased speed of the tool spindles, combined with a high-class air bearing, leads to significant improvements in quality and quantity, offering an output of up to 75 jobs per hour,” noted Grumbling.

Satisloh’s VFT generators utilize a twin action turning tip to double your tool life time and save tool cost. “Only about 50 percent of a standard MCD tool is used. Our new twin tool is assembled perpendicular to the lens. The complete radius of the tool tip is used in two consecutive actions,” said Ian Gregg, vice president of sales, operations, and product management.

3. BETTER SURFACES AND EDGING

Even as they are running faster, the new generators are producing higher quality surfaces. With the OptoTech’s patent pending async mode, unwanted vibrations can be minimized, resulting in very smooth surface qualities. 

Schneider’s XT produces high-quality surfaces, with tolerances to 1 micron peak to valley on freeform lenses.

Grumbling noted that an underutilized feature of Opto-Tech generators is the automatic shape-edging function to prevent knife-edged lenses. The generator automatically recognizes the edge thickness and processes the edge of the lens to avoid knife-edged lenses. The lenses will not split at the edges, so they can be further processed without any problems.

4. QUALITY CONTROL

The new generators have built-in quality control features. Schneider’s generator has an on-board Calibration & Verification System (CVS) so the lab manager can run a lens quality audit anytime during production.

“The CVS takes a map of the lens surface and compares it with the lens design (as replicated vs. as designed), ensuring consistent and high-quality results throughout the production day,” noted Cross.

He added that the Schneider generator creates and stores maintenance logs: “The machine will actually tell you when it is ready for preventative maintenance and then record when it was done. The machine requires an acknowledgement by lab personnel as to the status of the needed maintenance, making for easy tracking of preventative maintenance items.”

The Satisloh VFT offers Integrated Topography Measurement (ITM), which can be used to validate freeform lenses after surfacing. This enables measurement of lens topography right after surfacing for target-performance comparison with the design file.

5. WORKS WITH WHAT YOU HAVE

Manufacturers recognize that labs need to integrate the generator with the existing lab systems.

“Despite the high output, a big plus of Opto -Tech’s line is that you can also use existing digital surfacing/turning machines for the pre-cutting process,” said Grumbling.

The entire design of the Coburn Cobalt LTE  generator facilitates integration into smaller labs, including compact size and lower price point. Richard Gallant, senior applications service engineer said it delivers wet-cut quality results without the need for a water management system.

“The generator features Coburn’s proven mist-cut generating technology as well as air bearing, voice coil, and direct drive technology to increase cutting accuracy and lens throughput. The Cobalt LTE lens generator is ideally suited for small and mid-sized laboratories to produce digital and traditional RX lenses, and can be integrated with other qualified competitor soft-tool polishers,”  Gallant noted.

The Coburn generator is also scalable, as you can purchase a Cobalt LT without the freeform cutting axis then add this cutting axis later when the lab is ready to  produce freeform.

6. SELF-PROTECTION

Satisloh’s VFT generator offers an auxiliary Uninterruptable Power-Supply system, which reacts within a fraction of a second in case of unforeseeable power failure.  It triggers controlled retraction of the turning tip as well as Y-Axis, and shuts down the VFT PC system if the supply line is failing longer than 20 seconds.

“This new functionality eliminates the risk of machine component damage, down-time, tool and lens breakage,” said Gregg.

7. EXTREME PROCESSING

The new generators are designed to accommodate unusual and unique lens designs. Opto-Tech generators are equipped with post-processor optimization for processing extreme surface geometries, such as lenticular, bifocal and slab-off lenses.

Satisloh VFT offers Dual Surface Generation using two surface descriptions of inner and outer surface. The cutting of the two surfaces is achieved with a combination of milling and lathing, with the generator determining when each method is best. This enables optimum edge thickness in high minus lenses such as lenticular lenses.

Generator manufacturers have invested time and money into developing their new show ponies, and in fact, the new capabilities are not “just for show.”

“All of these features save time, improve quality and reduce the amount of lab re-dos. When you only have to do the job once, everyone wins,” noted Schneider’s Cross. “When you can maximize your throughput the lab can reduce the number of machines needed to produce the amount of work they have. This allows for smaller but more efficient uses of space, less labor, and quicker turnaround time. All of these combined will make the lab efficient and cost-effective.”


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May/June LabTalk 2017