CNC Lathe Machining
Scott Machine Case Studies
Scott Machine Inc. is a CNC machine shop that builds product to customer specification. We machine the components as specified and the customer is the boss. Understanding our role in the supply chain (manufacturer, not design) , it is not uncommon for Scott Machine to quote a product exactly as illustrated on the part print; but also offer the customer potential ideas for improved pricing and lead-time. In addition to machining, we have considerable experience in materials, heat treating, part marking, and packaging. We are not design engineers but we do suggest ideas and potential alternatives and the customer makes the final decision. Our goal is to help our customers such that it improves their position with their customers; then we manufacture the product as our customer directs. Read through the case studies below to see how we’ve helped our customers.
Solid Dry Film Lubricant
Challenge: The design engineer included the requirement for “Solid Dry Film Lubricant” to be applied to the threads. Solid Dry Film application is sprayed on the part, consequently overspray will occur. Since the engineer was silent on allowing overspray, this requires the part to be masked or taped off and then the masking must be removed after the Solid Dry Film dries. Masking and removing the masking is labor intensive and costly.
Solution: Due to the fact that the Solid Dry Film was to be applied to the threads to prevent seizure and that there was a thread relief it was suggested to modify the dry film note to allow minimal overspray.
Result: The design engineer agreed to the recommendation. As a result the special processing price was reduced 50% due to the labor savings. Additionally, lead-time was reduced 1-2 days, improving on-time delivery.
Challenge: This material specified a requirement to use 7075-T73 aluminum per AMS-QQ-A200/11
Solution: A more common aerospace aluminum is 7075-T7351 per AMS-QQ-A-225-9. After several searches for the originally specified material a request was made to allow an alternate material.
Result: The alternate material was approved, providing an easier supply chain channel for acquiring the material. As a result this change provides a lead-time reduction for the customer and this recommendation can be applied to various similar designs.
Engraving vs. Ink Stamping
Challenge: A purchase order was issued for two separate part numbers that required rubber ink stamping of the part number onto the parts. Each part must contain the ink stamped number.
Solution: There are various aerospace marking methods and each method is identified on the part print. Rubber ink stamping tends to be an older, widely accepted method; however, it has challenges in that rubber ink stamping is labor intensive; messy such that smearing is common and affects legibility and quality; and it tends to wear or erode over time.
Result: A recommendation was made to change the blue print to allow for Engraving, as opposed to rubber ink stamp. The recommendation would improve legibility of the part marking; improve thru-put in manufacturing; improve lead-time and reduce cost.
Packaging and Kitting
Challenge: A customer was buying six specific parts that we used together in the assembly of a larger product. Six purchase orders were issued and the parts were purchased independently. Coordination and inventory of the parts became unnecessarily tricky, and shortage of one part prevented the larger assembly from being completed.
Solution: Design a kit such that each kit contains one each of the six parts. The kit was given a new part number and the customer would order the kit (not the individual parts).
Result: The recommendation permitted the customer to flat their bill of materials; control only one kit number and ensure that the parts were combined to make the larger assembly. The customer had only one inventory item (the kit) and it made pulling stock for the assembly department much easier. Additionally the kit provided organization and orientation to ease of assembly.
Lead Time & Cost Reduction
Challenge: Our customer would order the castings and have them ‘drop shipped’ at our machine shop. Then the customer would place an order with us to machine the castings. This supply chain process had some inherent problems. First, castings have a long lead-time. Then, the casting order was large, yet the customer would only need a few machined or finished parts. A third concern was the debate over which company would own and carry the casting inventory. Originally our customer carried the inventory; however, over time the customer wanted us to take full responsibility of ordering the castings and carry any stock casting inventory. Last but not least, when casting quality issues would arise then it was never clear if resolving the issue was our responsibility or our customers’.
Solution: In our new process we would elect to make the parts from a common and readily available 17-4 PH Stainless Steel bar stock; totally eliminating the casting process.
Result: Every time we produced these parts we incurred one or more of these special issues. Consequently we investigated some options and ultimately recommended a blue print change allowing an alternate material (bar stock). In our new process we would make the parts from a common and readily available 17-4 PH Stainless Steel bar stock - totally eliminating the casting process. As a result, we could offer the customer shorter production runs with less lead-time and reduced the cost by almost 15%.