Hi Bob. To answer your "how do they work" question, there's usually some kind of intelligence in the bar feeder itself, whether it be a programmable ladder setup or a full blown microprocessor type. The bar feeder hooks in to your controller and as the material is fed into the machine the bar feeder monitors the position of the pushing mechanism and bar remnant length. When it gets to a certain preset point the bar feeder signals the controller that a bar change is needed. The controller then signals the bar feeder to initiate a bar change. The bar changer does its thing and when the change is complete the bar feeder signals the controller that it's finished and the machine can go back to work. There's a bit more 'smoke and mirrors' involved but that's the simple version.
First thing I'd probably do is check your G and M codes, see if there's a M code for a bar feed of some kind.
Second, bar feeders of the magazine type can expensive. Unless you're running serious production I don't know if they'd be cost-effective in your particular application.
We run 3 Iemca bar feeders here where I work. They have excellent up time and excellent excellent (yes, I said it twice) customer support.
Good luck.
