High-efficiency grinding technology becomes practical thanks to new dressing techniques.

Shops that swap out ceramic, vitrified, or resin-bond grinding wheels for metal-bond wheels increase productivity up to 30% and reduce grinding-wheel wear by as much as 70%. However, the difficulty of dressing small wheel radii and special profiles, while maintaining high grain profusion, has traditionally made them more expensive and difficult to use than they are worth.

Fortunately, a recently developed dressing system based on wire electrical discharge machining (EDM) technology provides a simple, machine-integrated, efficient, and cost-effective solution that will allow more shops grinding surgical implants, tools, and other precision components to reap the benefits of metal-bond grinding wheels.

Grains of diamond or cubic crystalline boron nitride (CBN), firmly embedded in a sintered metal matrix, produce very high material removal rates on the workpiece. Metal-bond wheels easily handle tough materials such as high-strength alloys, tungsten carbides, ceramics, and hardened steels. Better heat dissipation leads to cleaner, faster cuts than alternatives.

However, high material removal rates cut both ways – the extreme abrasion provided by metal-bonded diamond or CBN grinding wheels wear out dressing wheels quickly, reducing geometric precision. The silicon carbide wheels used in conventional dressing systems simply cannot achieve suitable results or create the intricate profiles that make metal-bond grinding wheels so attractive. The complex mechanical process of extracting grains from their metal matrix sometimes damages them, preventing selective grit exposure from its metal bond.

Conventionally dressing metal-bonded grinding wheels requires taking them off a grinding machine, moving them to a secondary piece of equipment for processing, and remounting them on the grinding machine. Repeated handling increases the likelihood of dressing and remounting error and imprecision. For shops with dressing machines, preparing grinding wheels still requires time and handling and rarely achieves precise results. Many shops send their grinding wheels out to subcontractors for dressing, magnifying complications

The primary traditional option for generating intricate metal-bond wheel profiles uses plating technology which cannot be dressed and must be shipped back to the manufacturer for re-plating. Another option is contact-based dressing methods with sintered metal-bond diamond wheels. However, geometry limits intricate profiles, preventing wheel shapes that hold complex contours and very fine, precise threads necessary to grind carbide parts, for example.

UNITED GRINDING offers the Studer WireDress system on the Studer S22 and S41 cylindrical grinding machines, which can include standard dressing units, enabling shops to run a mix of wheel types on a single machine. The system reduces the dressing unit’s size, increases the available work envelope on the grinding machine, and operates up to 20% faster than before, dressing wheels with grain sizes up to B151 at full wheel speed.

A power swivel enables the operator to set up left and right dresser positions in one unit to dress both sides of a wheel, creating higher shoulders and deeper profiles with one universal non-contact dressing tool.

A newly developed EDM-based dressing system addresses those problems, simplifying dressing and enabling greater use of metal-bonded wheels. The EDM integrates directly onto the grinding machine, eliminating handling errors. The non-contact system creates high-protrusion grains unachievable with other dressing methods for metal-bond wheels, generating the cutting performance of electroplated wheels.

EDM dressing uses quick sequences of extremely short, direct-current pulses to generate a discharge in dielectric oil (grinding oil) within the gap between electrode and workpiece. Tiny areas of the metal bond are melted and flushed away as small particles.

Studer’s WireDress, incorporated into some of the company’s grinding machines, allows shops to dress their own metal-bond wheels directly on the machine at full operating speed. Integrated into the grinder’s CNC control, it eliminates wear on dressing tools and labor-intensive reinstalling and resetting processes that follow external dressing.

The integrated EDM wheel dresses at 15mm/sec to 25mm/sec (0.59ips to 0.98ips) axial feeds, creating free geometries and intricate contours with 0.2mm (0.008") internal radii and 0.05mm (0.002") external radii while retaining the original shape of the grain. For example, dressing a 10µm radius on a 400mm (diameter) x 10mm (width) wheel takes approximately three minutes.

Integrated EDM wheel dressing saves energy as well as time, using 700W while it dresses and 60W in standby mode. Rotary dressing with a diamond wheel requires up to 1.5kW with an additional 1kW for sealing air.

STUDER’S WIREDRESS draws a wire electrode from a spool past the machining point at about 100mm/sec (4ips), guiding it with a groove on the outer edge of a thin ceramic disk.

The machine’s standard grinding oil acts as the EDM dielectric fluid, conducting the charge to the electrode that performs erosion dressing. The EDM spark jumps between the wire and the grinding wheel through a notch in the ceramic disk as the grinding wheel moves at 50m/sec to 120m/sec (164fps to 394fps) while it dresses.

A single EDM dressing wire spool contains 10km (6.21 miles) of wire, enough for 16 hours of continuous, uninterrupted dressing. The circumference of the ceramic disk includes two notches, enabling it to last for several thousand hours of service.

The system cuts the used dressing wire into short pieces of recyclable raw brass that gather in a collection container.

The lead applications engineer for Swiss-type lathes at INDEX explains machine advancements and the benefits they provide to manufacturers.

1. What features differentiate advanced Swiss-type machines from their more traditional counterparts?

There have been several significant innovations in Swiss-type machines. Pneumatically controlled guide bushings increase performance. The ability to quickly remove the guide bushing allows machines to shift between traditional and Swiss-type operation. Fluid-driven spindles eliminate wires from the work area to help with chip management. Precision-ground locating pins in turrets enable fast turnovers with tolerances in the microns. Turrets, especially those with an H-axis, increase machine flexibility. These advances are features of our TRAUB line of machines and some can be found in other machines in the industry as well.

2. For a shop that is used to traditional Swiss-type machines, what’s the most important feature to look for in an advanced machine?

A turret that has an H-axis will have a huge impact. Instead of indexing to set positions, the turret has an encoder and functions as a fully programmable radial axis. That allows up to three tools per station. Some machines use Y offsets to provide a version of this, but you lose your Y-axis. With an H-axis on the turret, you retain all Y-axis functionality with up to 24 tools on the turret.

3. How does a turret with an H-axis increase productivity and throughput?

The most obvious impact is having enough tools on the machine to handle multiple parts. In many instances, shops can change between four or five different parts without changeover. Beyond that, there are frequently trade-offs that occur due to tooling limitations of traditional Swiss-type machines. If you need seven tools to run a part optimally and you’ve got six stations on a gang, you’re going to have to identify a tool that can perform two operations, likely with a sacrifice in performance to each. With 24 tools, you can cut cycle and setup time while boosting flexibility.

4. Beyond benefits of setup and cycle times, are there other direct cost savings with this type of machine?

Absolutely. To maintain high precision with standard guide bushings found on traditional Swiss-type lathes, you must run bar stock that’s been turned, ground, and polished. With the TRAUB line, we use programmable, pneumatically controlled guide bushings that maintain a set pressure if there are slight irregularities in the bar stock. For many manufacturers, that can cut raw material costs by 25% to 50%.

5. What other ways do advanced Swiss-type machines justify the higher investment required?

In a lot of Swiss shops, machines are spec’d out for particular jobs. For example, you might win work on a family of bone screws, so you purchase machines set up specifically for those parts. If that work goes away, drops in quantity, or has significant design changes, you’re stuck with excess capacity for a specific part. If you’ve invested in an advanced machine, you have much more flexibility. If a job changes or is discontinued, you can easily bring different work onto the machine. In today’s market, that level of flexibility provides tremendous value that is often overlooked during the purchasing process.

FOR MORE INFORMATION: http://www.index-usa.com

Many medical issues are successfully treated with neural implants, but medical differs from allowing Musk access to your mind. Are you ready for symbiosis with AI?

As medical procedures shift to more minimally invasive and catheter-based technology and devices become increasingly smaller and more portable, the push for lighter and more robust components continues. Seventeen years ago, the U.S. Food and Drug Administration (FDA) approved deep-brain stimulation (DBS) as a treatment for Parkinson’s disease and today it’s used to treat depression, epilepsy, obsessive compulsive disorder, and more.

Advancements in miniaturization are also supporting projects such as the Restoring Active Memory (RAM) program funded by the Defense Advanced Research Projects Agency (DARPA). Its aim is to mitigate effects of traumatic brain injury (TBI) in military service members with neurotechnologies that facilitate memory formation and recall. DARPA’s end goal with RAM is a wireless, fully implantable neural interface for human clinical use. Expanding upon this, researchers are integrating computational models into implantable, closed-loop systems to deliver targeted neural stimulation to restore normal memory function. Last year, researchers successfully implemented a proof-of-concept system for restoring and improving memory function in humans, facilitating memory encoding using the patient’s own hippocampal spatiotemporal neural codes.

And then there’s Elon Musk’s idea, “symbiosis with artificial intelligence (AI).” Yes, the futurist billionaire behind Tesla, SpaceX, and Neuralink (founded in 2016) wants to implant a Bluetooth-enabled chip (featuring a USB-C port) connected to 1,000 wires, measuring one-tenth the width of a human hair, into your brain that will connect to a small computer worn over the ear. The implant will be small, requiring only a 2mm incision to insert because, as Musk muses, “If you’re going to stick something in a brain, you want it not to be large… you have no wires poking out of your head. That’s very important.”

While Neuralink’s focus is to understand and treat brain disorders, Musk’s presentation focused more on preserving and enhancing the brain while also “creating a well-aligned future” in the face of humanity that’s at risk of being left behind because of advancement in AI. He says even if AI’s impact is benign, “With a high-bandwidth brain-machine interface, I think we can actually go along with the ride and have the option of merging with AI.” The “ride” we go along with could mean AI’s connection with your brain, a Tesla, or both – one way to advance self-driving cars – but either way I say no thanks!

WATCH ELON MUSK’S NEURALINK PRESENTATION

This raises alarms and seems like an open door for cybercriminals to get brain data if someone “chooses” to interface with a computer. Then there are the ethical questions: Could your data be used to influence, manipulate, and control you? Who will have access to that data? Can it be shared?

Many medical issues are successfully treated with neural implants, but medical differs from allowing Musk access to your mind. Are you ready for symbiosis with AI?

New material with magnetic shape memory could have applications in medicine, space exploration, robotics.

Researchers at the Paul Scherrer Institute (PSI) and ETH Zurich have developed a new material which, due to its magnetism- activated shape memory, retains a given shape when it is in a magnetic field. The material consists of two components: a silicone-based polymer and droplets of a magnetorheological fluid.

The droplets provide the magnetic properties of the material and its shape memory. If the composite material is forced into a certain shape with tweezers and then exposed to a magnetic field, it stiffens and retains this shape – without the support of the tweezers – and does not return to its original shape until the magnetic field is removed.

While comparable materials have consisted of a polymer and embedded metal particles, researchers at PSI and ETH Zurich instead used droplets of water and glycerine to insert the magnetic particles into the polymer. This produces a dispersion similar to that found in milk. As fat droplets are finely dispersed in milk, the droplets of the magnetorheological liquid are finely distributed in the new material.

“Since the magnetically sensitive phase dispersed in the polymer is a liquid, the forces generated when a magnetic field is applied are much larger than previously reported,” explains Laura Heyderman, head of the Mesoscopic Systems Group at PSI and professor at ETH Zurich.

The researchers studied the new material with the Swiss Light Source (SLS) at PSI. The X-ray tomographic images produced with SLS showed that the length of the droplets in the polymer increases under the influence of a magnetic field, and that the carbonyl iron particles in the liquid partially align along magnetic field lines. These factors make the material up to 30x stiffer.

The magnetic shape memory of the new material offers advantages in addition to higher force. Most shape-memory materials react to temperature changes, creating two problems in medical applications: excessive heat causes cell damage, and it is not always possible to guarantee uniform warming of an object that remembers its shape. Both disadvantages can be avoided by controlling shape memory with a magnetic field.

This new material could have numerous applications in different areas:

– Catheters that are pushed through blood vessels to the surgical site during minimally invasive operations could change their stiffness. Using shape-memory materials, catheters could solidify only when needed and therefore produce fewer side effects, such as thromboses, when sliding through a blood vessel. Space exploration – The new material could serve as tires that inflate or fold up on their own for rover vehicles. Robotics – Shape-memory materials can perform mechanical movements without a motor, creating new possibilities for automation.

“With our new composite material, we have taken another important step toward simplifying components in a wide range of applications,” says ETH Zurich and PSI materials scientist Paolo Testa, first author of the study. “Our work therefore serves as the starting point for a new class of mechanically active materials.”

The researchers are now publishing their results in the scientific journal Advanced Materials.

See the new material in action

Heidenhain academy opens in Chicago; Okuma completes Dream Site 3 smart factory; Jorgensen Conveyors expands capacity

In brief...Tomohisa Yamakazi has been appointed chairman of Yamazaki Mazak Corp. Replacing him as president will be Takashi Yamazaki, who earned his bachelor’s degree in business from Xavier University and has served as managing director and vice president at Yamazaki Mazak.

Dean Hanaki, president and CEO of Okuma Corp., has been awarded the Order of the Rising Sun honor medal by the Japanese government for his achievements and contributions to the advancement of the machine tool industry. 

Omron Microscan has appointed Andy Zosel as its president and CEO. Zosel, who previously served as Omron’s senior vice president of engineering, has more than 22 years of experience at the company and has held several leadership positions in customer service, marketing, and engineering.

Robert Baker, former vice president of global operations for Stryker Corp.’s Joint Replacement Division, will serve as the new CEO of Glebar Co. Baker is a veteran of the medical device manufacturing industry and has spent the last 12 years in leadership positions in sales, manufacturing, supply chain, and commercial operations. Former CEO Adam Cook will now serve as chairman of the board.

Spirol has completed its Connecticut World Headquarters expansion. Begun in 2016, the expansion adds additional manufacturing space, state-of-the-art warehouses for raw material and finished goods, a quality lab and office space, and significant investments in new production technology, expanding the manufacturing area by about 40%. 

Merit Medical Systems Inc., a manufacturer and marketer of disposable devices used in interventional, diagnostic, and therapeutic procedures, has acquired Brightwater Medical Inc. The transaction consists of a $35 million upfront payment and potential earn-out payments of up to $15 million.

Founded by Dr. Robert Smouse, professor of radiology and surgery, University of Illinois College of Medicine, Brightwater Medical’s primary product is the ConvertX, a device that replaces a series of devices and procedures used to treat severe obstructions of the ureter.

Merit Medical intends to maintain Brightwater Medical’s production capabilities in Temecula, California, for several months while duplicating those capabilities in its catheter facility in Pearland, Texas, prior to transferring the ConvertX manufacturing operations to its Pearland facility.

“We believe our ability to align this product with our existing sales force, calling on interventional radiologists, as well as growth in markets outside the United States will allow for future growth,” Merit Medical chairman and CEO Fred P. Lampropoulos says.

Hillenbrand Inc. and Milacron Holdings Corp. entered a definitive agreement under which Hillenbrand will acquire Milacron in a cash and stock transaction valued at approximately $2 billion, including net debt of approximately $686 million as of March 31, 2019.

Jorgensen Conveyors has purchased and installed two important pieces of manufacturing equipment from Bystronic Inc. – a 250-ton press brake and 3kW fiber laser.

Both machines feature the latest in laser cutting and bending technologies as well as controls that seamlessly integrate with Solidworks 3D CAD software.

“This significant investment of nearly $1 million by Jorgensen Conveyors will greatly increase our capacity for growth and support our on-going commitment to quality and competitive pricing for our customers,” says John D’Amico, co-principal and director of sales & marketing.

Okuma America Corp. has completed their Dream Site 3 (DS3) facility in Kani, Japan. This smart factory uses cutting-edge technology, robots, and Industrial Internet of Things (IIoT) to manufacture vertical and horizontal machining centers and double-column machining centers to support the company’s product line. Innovative technology coupled with automation at DS3 can shorten production lead times by up to 50%.

This is the third smart factory built by Okuma, following DS1 (2013) and DS2 (2017) on the company’s headquarters compound in Oguchi. DS1 was one of the first self-contained, start-to-finish smart factories.

Okuma’s goal is for their smart factories to interweave automation with skilled techniques to achieve high-mix, low-volume production while maintaining production efficiency equivalent to that of mass production.

Heidenhain has opened its TNC-CNC Academy. This expanded CNC controls training center in the Chicago area is available for users at all levels, including those interested in 5-axis machining.  Classes are taught by specialists with many years of controls and CAM experience.

Academy classes include basic CNC training, in-depth training sessions on new Heidenhain control software upgrades, post-processor optimization, and specialized classes for connected machining and in-process inspection. The academy also offers classes for service teams to practice troubleshooting and repairs on real machine tools.

“Completing these classes will allow TNC users to improve efficiency and accuracy of the parts they machine by going beyond just the standard features and functions provided by a CAM postprocessor,” says Gisbert Ledvon, Heidenhain’s TNC business development manager.