Camcraft sees collaborative process development as a prime opportunity reduce costs and launch leading edge technologies with and for our customers. The new product development process was recently put to the test when one of our customers (a major provider of aerospace/industrial systems and components) experienced recurring machining issues while trying to develop a working prototype of a complex new fuel system component.
Prior to Camcraft’s involvement, prototypes were made in-house and sent overseas for heat treatment. All attempts at post heat treatment machining that met blueprint specifications had been unsuccessful. In an effort to isolate and correct the machining issues, our customer decided to have the process duplicated by an objective outside company. We were selected and received samples of the raw part to process.
Challenge One: Getting the Part to Market
How do you produce a part that no one else has been able to successfully manufacture?
We began our investigation by starting with the known facts:
- Material: Steel (17CrNiMo6)
- Part: Hydraulic accumulator with very deep internal channels
- Hardness Level: 60 HRC
- Heat Treat: Carburizing (processed overseas)
Design of Experiment: Using heat-treated parts provided by the customer, we attempted to machine the parts to the specifications provided to us. Even after developing special processes we could not get the part to match the effective case depth of 0.003” at 60 HRC on the deep internal features. This led us to believe that the heat treatment was a possible source of the problem. We tried a variety of heat treatment specialty companies but had the same negative results. As part of our due diligence process, we obtained the heat treatment measurement certification from overseas and were shocked to discover that the prototypes as delivered to the customer were not to spec. This confirmed our theory that the carburizing heat treatment method being performed was not effective.
Action Plan: We turned to Solar Atmospheres, one of the leading heat-treatment companies in the country, for a solution. They discovered that due to the size of the part, the normal number of pieces in the furnace actually absorbed enough heat to lower the overall temperature below the critical stage in the deep channels. This made achieving the proper case depth in the channels impossible.
After consulting with the customer and our team of engineers, Solar Atmospheres developed a process that achieved the desired hardness specification. However, the only way to reach the spec hardness in the deep channels in the center of the part was to reduce the number of parts in the furnace at any one time. The final number per batch was significantly lower than originally planned, resulting in an extremely expensive process. Due to product launch deadlines, our customer agreed to the heat treatment process and we were able to develop a robust machining process that met all specifications with no additional issues.
Challenge Two: Getting the Cost Down
Although the customer was pleased to have gotten out of a jam, no one was satisfied with the cost of the heat treatment – not Solar, Camcraft nor our customer, and so we began investigating other ways to bring the cost down and meet hardness specification. Unfortunately, as Thomas Edison once said, “we learned a lot of different things that didn’t work.” After working on various heat treatment parameters over eight months, we could not bring the price down with the process we were using and keep to spec.
A Different Approach: Our engineering team began to brainstorm. We circled back and reviewed the functional requirements of the part with our customer. We had the difficult discussion of challenging our customer’s engineering team to prove whether 60 HRC was really necessary. Based on the pressure specs and a thorough study of how the part functioned within the completed assembly, it was determined that 40 HRC should work in the intended application. We conducted additional experiments and confirmed that a uniform level of hardness of 40 HRC – at half the price – was the way to go from a manufacturing standpoint.
Results: The final stage was for the customer to put the newly machined parts on their test rig for a complete two month 24/7 failure test. The results confirmed that 40 HRC met all functional requirements, and changes were made to requirements to allow for the new heat treatment specification.
How We Did It
The positive outcome we experienced was the result of a methodology that is firmly embedded in our work habits. The essential component is a process development program that carefully investigates each element in a part’s production with a keen eye on quality and value. This includes looking beyond the blueprint to determine the functionality requirements of the part. In addition, we maintain careful collaboration with our customers at each step in the process, work with vendors who are the best at what they do, and facilitate trust between our customers and vendors by utilization of three-way communication and extensive procedure documentation. Development transparency allows us to add the greatest value to our customers, and is one of the chief reasons our customers rely on us for collaborative problem solving.
These elements create a repeatable methodology that meets a wide variety of challenges. This methodology – along with our continuous improvement program – is what our customers rely on to help them solve their most challenging applications.