Russ Willcutt joined Gardner Business Media as associate editor of Modern Machine Shop in January of 2014. He began his publishing career at his alma mater, the University of Alabama at Birmingham (UAB), where he produced magazines for the Schools of Engineering, Business, and Medicine, among others. After working as group managing editor for the HealthSouth Corp. he joined Media Solutions Inc., where he was founding editor of Gear Solutions, Wind Systems, and Venture magazines before heading up the Health Care Division for Cahaba Media Group.
One of the best things about using a CNC simulator during training is that it removes the fear of crashing an expensive machine, enabling students to gain confidence as they develop new skills. That’s the approach taken by Machine Training Solutions (MTS) LLC of Longwood, Florida, a software provider of training for CNC manufacturing companies and educational institutions. Whether conducted at a site of the customer’s choosing or at the MTS Training Center, classes contain knowledge-based exercises, video, and interactive labs and simulators to engage students and reinforce key concepts.
According to President Al Stimac, a key feature of the MTS system is that the programming methods and techniques used during the simulation training are identical to those in production machine shops. Led by industry experts, classes can be customized to meet a company’s needs, targeting areas such as:
CNC simulation of multi-channel, Swiss-type CNC lathes (10 axes in three channels with axis superimposition)
CNC simulation of complete machining on lathes and mill-turn centers (seven axes)
Programming and simulation of multi-spindle CNC machine tools (24 or more axes in eight channels)
Universal machining cycles for turning and milling
When should you choose rolled threads over cut threads?
Not all designers specify rolled versus cut threads when submitting part specifications, but there are good reasons to do so. Vallorbs Jewel Co. has formulated a Guide to Threads Tip Sheet explaining when you would want to choose one type over the other, and why. Considering the following points (abbreviated here) can help reduce production costs and improve strength and product performance.
Type of material: The rule of thumb is that materials that are easy to roll are difficult to cut and vice versa. This is true in the majority of instances. The determining factor is plasticity. Materials that have good plasticity are better suited for rolling.
Reliability: Rolling threads have an increased ability to resist fatigue. Applications with threaded parts and fasteners that are expected to operate reliability in high-pressure environments will benefit from rolled threads versus machined.
Required part strength: As with reliability, rolled threads provide increased part strength. Parts that are rolled have a root hardness that can be as much as 20 to 30 percent greater than those that are cut.
Chipless operation: Rolling creates burr-free knurls and eliminates chatter. A rolled thread is less likely to have any debris that flakes off the component and enters the operating environment.
Quantity/order size: Jobs with large production volumes may lend themselves to rolling, if other qualities to do not dictate that cutting be used instead (such as material selection). Production speeds in the rolling machining process are much faster than those of cutting.
Required tolerances: For parts that require high degrees of tolerance and limited variation from part to part, rolling offers significant advantages over cutting, ensuring that the last part produced will be as perfect and precise as the first.
Required surface finish: Applications that require fasteners with a superior surface finish will want to select rolling over cutting. Rolled threads are burnished and work hardened by the rolling process and, as a result, have a better appearance.
Type of thread: For applications that require very deep or coarse threads or those that require multiple threads, cutting should be the primary consideration. Rolling does not allow for the angle to be great enough to accommodate most types of multiple threads or very deep/non-precise threads.
Type of application: The application in which the fastener or threaded part will be used may also determine if rolling or cutting is employed. Some industries, such as aircraft components or nuclear components require rolling.
Whether running the machines or writing about them, those of us involved in manufacturing realize the critical role job shops play in the success of any country’s industrial enterprise. These smaller operations are both agile and efficient, able to respond quickly to the needs of customers with short lead times and low batch sizes. Individually, they are good employers in their communities and pump revenue into the local coffers. Collectively, these job shops form an impressive economic force, both statewide and nationally.
MakeTime—a Kentucky-based startup that matches the needs of OEMs with the available machine capacity of job shops, creating an online marketplace of “distributed manufacturing” profiled in this article—has produced a video spotlighting the contribution that small machine shops play in the state’s economy. While this short piece does a great job of tailoring the presentation to the culture and character of Kentucky, it’s just the sort of message that most states wish to convey to the larger world about their manufacturing base. It also sums up the sense of excitement that all of us at Modern Machine Shop feel when visiting a manufacturing operation that’s really busy and firing on all cylinders.
High performance machining (HPM) involves powerful equipment spinning tools at a terrific rate of speed. Add hard-to-machine materials such as titanium to the mix and you’re courting potential tool failure and damage to the workpiece. The Safe-Lock tool shank holder system for roughing applications from Haimer was designed to prevent such an event by preventing pullout and runout, and also preserving concentricity.
HPM places enormous demands on toolholding, with axial forces sometimes causing a slow “micro-creeping” movement that can pull the tool out of the chuck. Even frictional clamping methods with extremely high clamping forces aren’t always enough to avoid this scenario, the company says.
The Safe-Lock System addresses this problem with special drive keys in the chuck and grooves in the tool shank that prevent the milling cutter from spinning during extreme machining, or from being pulled from the chuck. This video shows the toolholding system in action. Pull-out protection and runout accuracy lead to low vibration and more efficient machining, allowing for increased cutting depths and feeds and therefore higher metal removal rates. Tool wear is also minimized.
Read this article from Modern Machine Shop about HPM of titanium using the Safe-Lock System.
This cutaway of the Safe-Lock shows the drive key at the bottom of the shank of the tool holder, which grips into the groove in the tool shank.
Chip evacuation during groove milling operations can be a challenge. Cuts are often narrow, deep and sometimes hard to address with standard nozzle-type coolant systems. Sandvik Coromant addresses this dilemma with the CoroMill QD internal coolant solution. Not only does this tool effectively clear the groove as it’s being milled, it also provides an improved surface finish and more-predictable tool life.
Correct clamping force and repeatable insert positioning is assured by the device’s quick-release key. Inserts can be changed within the machine, and the tilted insert seat features a rail both for stability and security. In addition, driving collars provide extra stability when using large-diameter cutters. This video shows the CoroMill QD in action, comparing the results with a groove cut via standard dry milling.