Bar Feed Machines

A company always choose the best for their machines. Choosing the best bar machine was one of the considerations.They choose their machines maybe because they were simply contented to follow the recommendation of the distributor who sold it the lathe. Or it may own a battery of bar machines equipped with a certain type of bar feeder and just be following suit. Or the company may make the decision only after a thorough analysis of bar-loading time, setup time and other factors that affect productivity.

The best bar feeder is the one that best meets the needs of the user for his or her particular circumstances, and those circumstances are probably as varied as the number of shops that specialize in turning. To prove the point, we have assembled several examples of shops that operate bar feeders. For the purpose of covering the major types of bar feeders, we focused tightly on a particular type of bar feeder at each shop instead of trying to catalog all of the shop's bar feeders or to go into detail about the principal operations of the shop.

You may have purchased a new CNC single-spindle lathe, screw machine or some other bar machine recently, or perhaps you are looking to make your next bar machine acquisition. It is hoped that some of the considerations this article raises about bar feeder selection will answer some of your questions and help you to choose the best bar feeder for that new machine.

The hydrodynamic bar feeders, with their cannon-like appearance, seem out of place given the rectangular look of the shop's other bar feeders. But appearances can be deceiving and, in fact, the hydrodynamic bar feeders are considered more efficient for the jobs they are being used for than any other type of bar feeder in the shop.

Sometime we use CNC lathes primarily for jobs consisting of relatively small quantities of parts with fairly long cycle times, and those lathes are equipped with hydrodynamic bar feeders. One bar may last for 1 or 2 hours, and the job may require only two or three bars. It takes only one or two minutes to load a fresh bar, so the brief interval that the lathe stands idle while a fresh bar is loaded into the bar feeder does not have much of an impact on the efficiency of the operation.

Adding to its suitability for short-run operation, the hydrodynamic bar feeder changes over for the next job relatively quickly. You simply decide which of the six tubes most closely matches the bar size to be run, rotate the drum to that tube, insert an appropriately sized liner in the lathe spindle, load the first bar, feed it into the spindle, and you're ready to run. That's about as quick as it gets. Setup time on the magazine-style bar feeder can be considerably longer: there are more adjustments to make, more settings to change.