Bar Loader Boosts Uptime For Multispindles

Amtec Precision Products, Inc., Elgin, Illinois, is a producer of precision turned parts for the automotive, hydraulics, appliance, defense and other industries. The firm prides itself in being the sole supplier to "virtually all" of its customers. It designs a manufacturing process for every job, bringing to bear an array of precision turning equipment.

Amtec's turning machines include approximately 90 Gildemeister multispindle bar machines with capacities ranging from 0.375 inch to 4 inches. (The firm's equipment list identifies more than 300 primary machine tools in addition to numerous secondary machines.)

Many of the firm's multispindle bar machines have conventional stock reels with bar tubes that must be loaded manually. Andrew Hain, executive vice president for Amtec, explains the problem with manual loading: "When one of our older Gildemeisters runs out of stock, it shuts itself off," he says. "The machine operator must go to the front of the machine, remove the bar end (remnant) and discard it, and then go to the back of the machine and load a fresh bar into the stock tube. Loading the fresh bar is no easy task: He must literally pound it through the bar tube's compression springs and through the turning machine collet to the stock stop. In the process he will sometimes peen over the end of the bar, making it difficult to remove.

"It takes the operator 6 to 8 minutes to load fresh bars into the stock tubes," Mr. Hain continues. "The machine remains idle while the operator does this, and he may need to reload the machine 12 to 14 times per day. That's well over an hour of production time lost per day per machine.

We wanted to automate the bar-loading operation to eliminate that lost production time," Mr. Hain says. "One option was to buy a magazine-style bar loader that attached to the back of the multispindle machine and loaded bars into the existing stock tubes. The problem with that solution is that it increased the length of the machine by about 15 feet. Given the large number of machines involved, plant space limitations precluded that option. The solution to our problem turned out to be a magazine-type bar loader, made by Pietro Cucchi America Inc. (Elk Grove Village, Illinois), that replaces the stock reel of the multispindle machine. The bar loader attaches directly to the back of the machine, making for a compact arrangement."

The multispindle machine bar loader is similar in operation to a magazine-style bar feeder for a single-spindle lathe. The operator can load 20 to 30 bars into the bar feeder, and the unit will load the multispindle machine automatically. Instead of pounding bars into stock tubes, the operator is now free to load other machines, check critical dimensions on parts or attend to other assignments. The bar loader automatically extracts bar ends, and a monitoring system accurately positions the bar for machining, eliminating the familiar short-part problem.

According to Mr. Hain, the multispindle bar loader provides an additional 90 minutes of uptime per machine per day. He added that when a new multispindle machine is purchased, it will be purchased without a stock reel and will be installed with a magazine-style bar loader.