Reducing setup time, giving the spindle clearance and making job changes simple and accurate are focus of five-axis workholding systems
By Sarah A. Webster
Editor in Chief
With five-axis machines continuing to grow in popularity, given their more accessible prices and programming software, demand has also grown for modular workholding systems specifically built for these machines that can be changed out quickly and deliver reliable, accurate fixturing job after job.
Several leading workholding providers have developed all new five-axis workholding systems that deliver just that.
While Jergens, Inc. (Cleveland, OH) has offered its popular Fixture Pro 5-Axis Workholding solution since 2010, Carr-Lane launched a competing system, the CL5, at the Canadian Manufacturing Technology Show in Toronto last fall. And several other workholding providers say they offer modular systems that are just as fast, accurate and reliable as systems built specifically for five-axis machines.
While the five-axis workholding systems each offer unique specifications and benefits, they do have this in common: They are selling a system that lifts the part, in order to give the machine spindle enough clearace to do its job; they all promise rigidity and accuracy in clamping; and they all promise the ability to quickly change out fixturing with specified accuracy.
Workholding is an area where the metric (or International System of Units) and US customary units of measurement can come into conflict, more so than in other areas of manufacturing. For example, attaching a metric riser and vise to a subplate with boltholes in inches may require an adapator plate or other modifications. Some of the new systems try to eliminate those complications.
A Complete System
The FixturePro system, introduced by Jergens at IMTS in 2010, consists of a wide range of tooling designed for five-axis machining centers. It consists of tight-tolerance subplates, risers, pallet changers and top tooling with repeatability of ±0.0005″ (0.013 mm). Top tooling includes five-axis vises, collet fixtures and dovetail vises and more. The line offers a variety of mounting accessories and configurations providing flexibility based on part requirements. The system is also designed to work together with other Jergens quick-change fixturing including the Ball Lock Mounting System. Jergens says that setup time can be reduced by up to 90% or more with FixturePro.
Paul Kieta, national sales manager, Jergens Workholding Solutions Group, said that the thing that makes FixturePro special is that it is a system, first and foremost. Because of that, he said, “it can be adapted for any situation and moved from machine to machine. As jobs change or new machines are purchased, the workholding tooling can still be used.”
Prior to FixturePro coming to market, Kieta said, a shop would have to “search for the right set of tooling, build custom tooling or adapt non five-axis tooling.” However, he said, FixturePro, which is now Jergens’ fastest growing product line, takes the guesswork out of five-axis fixturing, offering a combination of standard components designed to work with one another that can be swapped out on-the-go.
“They don’t have to manufacture their own risers, worry about tolerances or repeatability between set ups or machines. There is a lot to consider, so we’ve tried to take those variables out of the equation. You know what the stack up and tolerances are going to be, and the repeatability you can get, from one setup to another.”
All of this helps to reduce setup time, which is an area of cost savings that seasoned manufacturers are now attacking, given that they’ve taken excess cost out of many other areas of their business. “More and more people are beginning to look at setup time as an area where there is a lot of time to be saved,” Kieta said. “We find that two hours of setup time is pretty easy to find, particularly with customers who are running shorter batches with more changes.”
Kieta noted that Jergens also will build custom five-axis workholding solutions to meet specific requirements and bring tolerances and repeatability into an even more specific range.
Another benefit to the FixturePro system and the Drop & Lock Pallet Changer, Kieta said, is that you can literally take a part off the machine while still clamped, take it to your CMM, attach the assembly to the measurement table, measure the part and return it to the machine all while clamped in the original fixture, eliminating the need to resituate the part in new fixtures for measuring or secondary machining. “They can quickly get their location, and then they are good to go,” Kieta said.
The FixturePro system is US designed and made to metric dimensions. Kieta said the system is an international product and the wide acceptance of metric in manufacturing today made using a metric standard the logical choice.
The CL5 System
Colin Frost, Chief Business Development Officer, said Carr Lane (St. Louis, MO) had been researching available quick-change options for five-axis machines, given the rapid growth of the advanced machines. “They all required adaptors or extra pieces people had to bolt on to get these items to work together,” he said. “That doesn’t really make a lot of sense.”
Simply importing parts didn’t make sense either, however. “There’s a whole variety of issues in getting them to work well in America, where there is this inch-versus-metric issue,” he explained, noting that m10 and ½-13 threaded bolts look very similar and can frustrate customers trying to work between two measurement worlds.
So Carr Lane worked with its longtime workholding partner, Roemheld of Germany, to develop a system that worked fuss-free in America.
Launched at CMTS in Toronto last fall, the CL5 quick-change, five-axis workholding system consists of three components: a subplate, a riser and top tooling made up of a vise or a fixture plate. The risers and vises are designed and built in Germany, in conjunction with Roemheld.
The subplate transforms a T-slot table into a modular fixturing plate, allowing flexible and easy clamping and locating of other tooling and/or fixtures. Every plate has built-in clamping and locating for risers, which allows for quick and accurate setups.
The Quintus quick-change riser allows five-side part access and combines the riser, quick-change capability and precise location in one piece. Carr Lane says that no other accessories are needed, and a range of fixture plates or vises can be readily mounted on top of the Quintus.
One of the most useful features of the system is its zero-point mounting system, with which repeatability of fixture location is 0.0004″ (0.010 mm) or better. The Speedy Zero-Point Quick Change Mounting System has several possible configurations.
Zero-Point Locating Posts provide a solid datum for two-axis location (similar to a Round Pin). Relieved Locating Posts locate in only a single axis (similar to a Diamond Pin). Floating Posts can move 0.010″ (0.25 mm) in all directions, so they provide additional clamping force without affecting location.
Carr Lane offers a wide range of vises and finds that five-axis customers are increasingly leaning toward concentric vises because of easier center alignment. “With the concentric vise, the jaws are within three-tenths of the center of the table every time,” Frost said.
Since the end of the recession, Colin said many companies are investing in five-axis machines with the expectation that they need one in order to credibly compete for business. Colin said the CL5 system brings more ease of use to those often-new five-axis machines. “It is truly a mix and match system,” he said. “The CL5 can be used all together or separate. People respond pretty well to having no adapter plates or additional bits and pieces over time.”
He added: “The customers don’t have to be worried that the Quintus and the vises are metric, they can bolt it to their inch subplate.”
Modularity is King
Brian O’Rell, president at Raptor Workholding Products (Simi Valley, CA), said his company offers flexible, modular workholding for five-axis manufacturing, an area that he said has been growing rapidly in recent years.
“Modularity is becoming more common,” he said. “We try to do everything in one shot. That’s what we’re about.”
O’Rell acknowledged that the trend is a bit ironic, given that machine shops are their customers. “They want you to deliver a product that they don’t have to do anything to. They don’t want to even drill a hole,” he said. “So we try to do it all for them.”
While Raptor doesn’t market its five-axis offerings as a complete system, he said their offerings are, essentially, no different than those that bill themselves that way. You still have to get a subplate, riser and top hat tooling, whatever that happens to be.
Raptor’s modular workholding parts are, for the most part, built in the US and designed in US customary units.
Raptor’s most popular product in this area is its RWP-001. A 1.5″ (38.1-mm) dovetail holder for milling and turning applications, the 001 offers superior clamping strength while allowing access to five sides of the workpiece. This five-axis fixture supports a maximum workpiece weight of 30 pounds and a size of up to 6.75 in.3 (110.6 cm3).
Raptor dovetail fixtures provide rigid clamping while exposing five faces of the workpiece, and most features can be completed in a single operation, O’Rell said. An optional locating pin ensures that the part is placed accurately and the spring-loaded clamp can be tightened with a simple hand tool.
O’Rell said the patent-pending Raptor dovetail spring-loaded clamps require only 1/8″ (3.18 mm) of material to hold the workpiece. That means less waste, easier prep and no distortion or clamp creep. You prepare all your parts with a single dovetail and utilize the same fixture for every part.
Steve Kane, global sales and marketing manager at Kurt Industrial Products Division, said the company has seen steady growth in sales of five-axis workholding, and he believes that is driving self-centering vises, especially those with dovetail features for secure holding.
Kane said the company’s five-axis vise offers a pull-type feature which lowers stationary deflection and helps hold parts tightly in place. Kurt’s AngLock five-axis vise allows load and unload vises easier thanks to its 0.625″ (15.88-mm) stroke capabilities. Other five-axis vise options like Kurt’s Leader MMY Chucks and Schenke 5 Axis Vise are also available for your five-axis machining needs. “We actually have 15 different solutions for holding any size part, from the smallest part to the largest part somebody can hold on a five axis,” Kane said. ME
This article was first published in the February 2014 edition of Manufacturing Engineering magazine. Click here for PDF.
Published Date : 2/1/2014