Solutions Showcase
Off-Hand Brush Deburring of Connecting Rods Case Study

Eliminating hand deburring operations is a common initiative being undertaken by many manufacturers. These tedious, labor-intensive operations are not only frequent bottlenecks in the production process, but they also affect the profitability of an organization in other ways. Human error and inconsistency contribute to high scrap rates and reduced productivity, and repetitive motions increase healthcare costs arising from muscular skeletal disorders. Thus, there exists a significant motivation to automate deburring operations that are currently being performed by hand.

Unfortunately, it may not always be feasible to automate a deburring operation. This may be due to budget limitations that preclude capital expenditures for new equipment, or it may be due to limitations of the current manufacturing process that prevent an automated solution from being integrated into it. Thus, it is often necessary to either live with the current process or explore ways of improving it in order to achieve some economic benefit.

This was the dilemma facing a manufacturer of automotive connecting rods that were being machined on a high-production transfer line. In order to maintain the required surface finish, they found that it was best to remove the burrs left on the edges of the two notches by the rough boring operation before the final honing operation. Six laborers were assigned to pick up and deburr each of the loose connecting rods as the moved on a conveyor between the two operations. To meet production requirements, these people were required to perform this operation on as many as 1800 pieces per hour using a deburring knife.

Naturally, this situation left much to be desired. The high production volume resulted in this operation becoming a frequent bottleneck. The actual average number of complete parts coming off the transfer line varied between 1200 and 1500 pieces per hour. The pile of unprocessed connecting rods that many of the "deburrers" kept next to them took up floor space and presented a safety hazard. In addition, the 12% scrap rate was severely affecting the bottom line.

The end user first looked at an automated solution. Due to the location of the burrs and the manner in which the connecting rods were being transferred between operations, the only alternative that could seemingly be integrated into the existing process was a robotic one. Not only was it unlikely that this type of automated system would be able to meet the high production rate, but such a solution would require a very significant outlay of capital. Fortunately, the end user was able to find some big cost savings by re-designing the off-hand process around a little brush.

For an investment of $500, four pneumatic die grinders returned dividends in the form of increased productivity and decreased operating costs. By using a 2"-diameter crimped-wire wheel as the deburring media on these 20,000-RPM power tools, it was possible for four laborers to perform the work that had previously been done by six. This reduction in labor was accomplished even though the average number of complete parts coming of the transfer line increased to a very consistent 1700 per hour. In addition, the scrap rate decreased to 8% after the process change.

The new process carried with it no noticeable increase in operating or overhead costs, and the consumable cost-per-part-deburred was less than a penny. Not only were there some very quantifiable immediate economic gains realized by the change to an off-hand brush deburring operation, but there were also resulting improvements that impacted long-term costs such as healthcare and workers' compensation. The new procedure was more ergonomically correct and resulted in a lower potential for repetitive motion injuries.

Although it may not always be possible to eliminate a hand deburring operation, this example proves that it is usually possible to improve it. If you would like assistance with a deburring application with which you are struggling, call Weiler's Application Engineering Department at 1-888-299-APPS(2777).