By Sean Fenske, Editor-in-Chief
 
With every new customer come new expectations, new voices, and new preferences. This is not all instantly recognized after the initial meeting and can even change with new projects from the same company as new stakeholders emerge. As such, it’s important to have a plan in place for the exchange of information and details about each project, even at the component level.
 
Similarly, it’s important to have a working plan for occasions when important information isn’t provided. This can be due to an oversight or the inexperience of a customer specifying a certain part. In these instances, a supply partner must leverage its expertise and experience to identify the missing information that is critical to obtain from the customer, while also knowing what information can be determined from other details.
 
To help explain how this can play out, Tim Steele, founder and CEO of MicroSpec Corp., has addressed several questions in the following Q&A. As an expert in extrusion, he explains what questions need to be answered, how to ensure a proper inspection, and the importance of clear communication between supplier and customer.
 
Sean Fenske: Can you please clarify what is meant by unspecified details for extrusions?
 
Tim Steele: In extruding a new part, the engineering drawing is often quite incomplete which can pose a variety of problems for the extruder of the part but also for the OEM customer. Drawings for prototypes often provide only the essential specifics of the new part; it is common that the drawing only specifies the raw material to be used and the dimensional specifications of the tube with or even without tolerances. With large and small technical gaps in the drawing, the extruder is faced with the task of determining what those gaps are prior to extrusion of the part. As such, communicating with the customer is key to determining what the new part is all about.
 
Fenske: If a customer’s drawing or order doesn’t include details, how do you determine what parameters to use?
 
Steele: The function of the part needs to be understood by the extruder and we learn about the part’s function generally through conference calls and emails. We typically start off with questions like:
 

• Does the part have something passing through it and what is it that passes through?
• Does the part have to fit inside something else (in which case, maximum outside dimensions come into play)?
• Does the surface lubricity of the part play a role in function?
• Does the part need to be straight?
• Is the part subject to normalization and should the part be annealed to stabilize dimensions?
• Do the dimensions of the part stack?
• Does the part have a tolerance for gels?
• Are there cosmetic attributes of which we need to be aware?
• If the part is cut to length, are there special attributes of the cut critical to function?
• How should the part be inspected?
• How should the part be packaged?

 
The list of questions can almost be endless and attention to every aspect of the part is, of course, critical to the function of the part.
 
Fenske: What details are absolutely critical for you to extrude tubing for a customer? Are there other details that can be left out and you’re still able to provide the product?
 
Steele: Invariably, we do not get all the answers we are seeking because, with first time parts, we and the customer “don’t know what we don’t know.” We learn about the more obscure, yet critical, features of the part by extruding the part and then uncover unspecified aspects that fail when the part is tested functionally. On complex parts, this occurs frequently.
 
Fenske: How can you determine if the quality is achieved if you don’t have specs against which to measure?
 
Steele: Inspecting a first-time part is complicated when there are unknown features of the part that affect function. We recently extruded a very small nine lumen tube that had an engineering drawing that appeared to be complete with regard to dimensions, tolerances, and materials. But the part was so small the minimum tolerances on the walls and webs were unachievable. The part was quoted as a best effort part and we faced the task of developing a new tolerance that could be reliably achieved. This part had 34 inspection points so it was very time consuming to inspect manually. Even with one of our OGP Smart Scopes measuring the same part twice, we would see varying results due to the extremely small dimensions of the tube. This part has become a production part but the development of the inspection procedure took multiple extrusion runs and we stopped development of the procedure when we determined we had reached a point where the OGP could not do any better.
 
Fenske: How important is communication in a situation like this? Does this simply require someone to pick up a phone to discuss further details?
 
Steele: In developing the aforementioned part, communication with the customer was key to reaching a mutual understanding of how to make and inspect that tube. We went back and forth dozens of times, discussing the features of the tube and how we were having difficulty finding ways of measuring and getting similar results. Compounding our frustrations was that this tube was made of soft polyurethane and the dimensions would normalize after extrusion. We had to develop dimensional targets in extrusion that would produce the desired dimensions after the tube had been annealed. Although the extrusion process for this tube had been validated, we are still learning with every extrusion run more about the process. Without effective communication, validation would never have happened.

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