One factor that makes Haas Automation such a successful machine tool builder is the well-planned use of workholding set-ups in its manufacturing operations. Haas maximizes productivity, which is evident in the quality and cost-competitiveness of its new machining centers.
For example, an interesting, and highly productive, hydraulically actuated clamping system that’s been in use at the Haas plant for nearly five years uses Kurt Manufacturing’s MoveLock™ vises. The cell set-up at Haas is an example of the ways that manufacturers strive to automate in every way possible, to lower costs while increasing output.
“The goal with the MoveLock vise set-ups was to automate the machining operations used to produce various size round components for machining centers,” reported Phillip Linscheid, machine shop manager for Haas Automation. “We have several of these machine set-ups, which vary between one and four MoveLock stations mounted on trunion tables. A Motoman Hp 165 robot provides the load/unload operations. There is no fixture set-up labor required once the pre-machined jaw plates are installed in the MoveLocks. Part runs vary from just a few components to several hundred. So the different set-ups, from one to four clamping stations, give us the flexibility and efficiency needed for varying quantities.”
One example of its MoveLock set-ups has four MoveLock vises mounted on a HRT310 rotating worktable of a Haas VF4 machining center. The custom-machined jaws hold 4140 and 12L14 steel parts with turned diameters from 2.75 in. to approximately 8 in. thick and in thicknesses from 0.5 to 3.75 in.
As an example of the machining done with this set-up, one of the parts calls for a 5/8 inch Z-carbide insert run at 1222 rpm/ 50 inches per minute and a 0.5-in. Z-carbide insert doing counter boring at 1,250 rpm/ 15 ipm. This set-up, according to Linscheid, improves output and efficiency by more than double over the previous process.
With these kinds of feeds and speeds, part immobility during the machining process is imperative. The MoveLock vises ensure rigidity because they are more than just piston-driven clamping devices. They produce up to 2,500 lbs. of clamping force using 3,200 lbs. of hydraulic pressure. With a 5/16-inch stroke, they can be positioned on a base plate so that the jaw opening is limited only by the work envelope and still produce adequate clamping pressure to accommodate a wide range of part sizes.
What’s critical about the MoveLock’s clamping pressure is that it incorporates the proven Anglock design to prevent jaw lift during clamping. As hydraulic pressure is applied to the clamping piston, it is driven forward to locate on an internal ball segment. While the lateral force is clamping the part, downward pressure is being applied to the movable jaw, minimizing and preventing part lift. For every pound of clamping force on the jaw, there is a half-pound of force exerted down on the movable jaw. For the application at Haas Automation’s plant, this clamping rigidity ensures that tight tolerances are held typically to ±0.005 inch on bolt circles.
Haas Automation machines batches of 150 to 250 of differing-sized round parts in these MoveLock set-ups each week. Linscheid reports that without the MoveLock vises, Haas would not be able to run the parts in a robot cell, or to achieve two to three times greater output versus its earlier set-ups.
