Case Study

Objective

Evaluate manufacturing materials and processes to improve the longevity and function of a rock guard used in a variety of conditions.

Considerations

Tractor-mounted mowers are used to maintain roadway shoulders and medians, to clear vegetation from large tracts of land, and to service parks, fields and public spaces of almost any size. These jobs require rugged equipment that can tackle a wide variety of conditions. But when Cypress was asked to quote on a standard part — a rock guard for sickle bar mowers, used on a large number of agricultural machines — we were provided prints that were more than 50 years old. In all that time, no one had thought to review the part to see if decades of advancements in materials and manufacturing processes could improve its function or longevity, or to see if alterations could reduce the cost to manufacture it.

We asked for the opportunity to evaluate the materials and production requirements of the rock guard in order to improve the utility of the part while decreasing manufacturing costs and production time.  

Solution

Because the rock guards are used on a large number of existing mowers, no changes could be made to the size or shape of the part, but everything else was up for review. We quickly realized that by utilizing investment casting rather than sand casting, we could make several improvements in a single step.

Investment casting allowed us to use a much stronger alloy. Originally, the parts were made of iron, but steel created a 10% lighter guard. Steel also allowed us to craft a more rugged part. We heat-treated the cast guards to improve their hardness and achieved a Rockwell C rating of 58 to 62, but with a significantly deeper case depth than the original part, significantly extending longevity.

The original process created four separate pieces. By shifting to investment casting with second operation machining, we were able to make just one, significantly cutting production time and improving quality. Investment casting enabled us to accommodate a more complex mold with tighter tolerances, and we were able to manufacture a larger number of parts while maintaining higher quality standards in every run.

Results

Manufacturing technologies are always improving. By taking advantage of our expertise and allowing us to evaluate materials and processes, our client was able to reduce production costs by 25% and extend product life by 300%.