A bar feeder is the workshop equipment that undertakes the task of automatically feeding metal bars into CNC milling machines. Those types of tools are used to increase the productivity of a workshop and allow CNCs to work unattended and during the night or weekends.
Bar feeders are considered to be a CNC extension, so they are directly connected and controlled by the latter. Operators, however, may also set a particular feeding rate that is fit for an application manually. The metal bars are held on the storage chamber and are taken out one by one to be passed into the CNC milling chamber. Bar feeders today are capable of detecting abnormal operation, stopping the feed automatically.
Things to consider when buying one
There are many different bar feeder models in the market today, offering different production qualitative and quantitative characteristics. As these machines are destined to work together with CNCs, compatibility and sizing are especially important when considering buying one. Here's a list with the most significant factors to consider before making a bar feeder choice:
Magazine Size Needs
The size of the magazine that holds the bars is a critical factor to consider when buying a bar feeder. Determine what type of bars you want to process (gauge class) and calculate how many of them can be held on the magazine. Then consider the feeding rate to figure out how many hours of unattended operation you can get from the feeder. Usually, a minimum of 8 hours (night shift) should be preferred.
Lengths of Part and Spindle
Each part that is produced on the CNC requires a specific amount of bar length to be realized. Machinists should calculate the total bar size, subtract the length of the part that is held on the CNC spindle and divide with part length to determine the number of the workpieces can be produced with each bar. This can indicate if a bar feeder choice is good or not, as sometimes a slightly longer bar could be enough for one whole extra product.
Safety of Operation
As bar feeders are required to work well for long periods of time without the presence of personnel, it is very important to have safety features that monitor the operation and check for errors in the process. Some safety net mechanisms that are used by modern bar feeders include sensors, load meters, infrared beams and streaming webcams that send video technicians remotely.
Space Requirements
Floor area is sometimes a workshop's most limited resource, and bar feeders are known to challenge this. As the machines get fixed on the spindle side of the CNC and since they are relatively long in almost all cases, machinists should carefully calculate whether their workshops have enough space for the addition of a bar feeder. Not only should the bar feeder fit next to the CNC, but there should also be enough space for maintenance, access to all compartments, and space to clench/unclench bolts. If the bars are loaded onto the machine with the use of a small crane, there should also be enough space to accommodate its maneuvering as well.
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