Advice for the new engineer: Selecting a fabricator
Selecting a fabricator is not a casual decision. In most cases, your employer and the vendor will be in a relationship for a long time. Once a vendor has been used once, they will usually be utilized over and over as new parts need fabricating.
Here I am speaking about vendors who fabricate parts of some sort, as opposed to distributors or assemblers. Plastic molders, machine shops, board houses and the like. Once you have a list of potential fabricators, you will need to start narrowing it down.
We are going to give the rookie engineer the insight of a veteran. This includes selection criteria and other advice. It may not all apply to your situation today, but don’t disregard the fact that it may come up in the future.
- Price — This is a sliding scale based upon the raw material costs, but it will do you no good if a vendor wants to manufacture for $90 the product you intend to sell at $80. Consider the amount the vendor is charging and what your budget is for the final Cost of Goods Sold (COGS).
- Lead-time — a 3-month lead-time is unacceptable for most items, even if the price is awesome. Understand your acceptable lead times before engaging a new fabricator. Expect faster parts to be more expensive.
- Special materials — What types of material are you working with? Assembly shops like to work with material that is easy to cut like aluminum and plastics. Plastics with glass filler wears tooling out, as does hardened steel and aluminum anodized finishes. Anodized finishes especially TYPE II hard coat will absolutely annihilate anything but the hardest tooling. Garolite, aka G10, aka FR4, is another destroyer of cutting tools, it also requires the use of vacuum and exhaust equipment. Materials like titanium and glass require special tooling and skills to work.
- Traceable or Certified Materials — Does your design require certified materials? Can the vendor provide that? Also, will they provide the paper work required for your own records?
- Certified work — Something like a welded joint may need to be done by certified welders. Make sure that the vendor is indeed certified to do that kind of work.
- Prototype/Short production runs — Do you require samples or a short run? Can they provide this? For example, some liquid seal manufacturers won’t fabricate a custom seal until a large number is ordered. Sometimes, they simply can’t do a short run. Plastic molders can’t provide a sample of anything until the mold is made. At that point, you have already purchased the mold.
- Agency approvals — Consider any agency approval that will have to be met. For instance, the NFPA typically demands that only certain devices and materials are used in the construction of equipment. Don’t take it for granted that a prospective vendor is aware of this. It is your responsibility to ensure that they are following those regulations. The consequences of regulatory nonobservance can be extremely costly and sometimes life-threatening.
- Design Services — Do you require design services? Vendors know their tool limitations and capabilities. They likely also know how to optimize for these tools better than you. They can often provide suggestions to streamline the design or at least make it more manufacturable. Be aware of the costs here: if their involvement in design or analysis gets too involved, they will usually start billing. Make sure you know when this billing will start and how much it will cost. You don’t want to have to explain to some angry bosses why they received a surprise $12,000 bill for engineering services.
- Data format — Find out how you be conveying information back and forth to the vendor. Can they work with the file formats you are using? Will they even accept email? That may sound absurd, but I have worked with vendors that insisted on drawings being mailed next-day air. Also, despite the prevalence of 3D CAD software like Inventor and SolidWorks, it is still very common for some shops to only accept 2D mechanical drawings. You should always make mechanical drawings to accompany your 3D models. If these are the primary design document, you will have to be especially diligent.
- Dimensional Accuracy — You may require ±0.002, ” and the vendor can only guarantee ±0.005”. It is time to look for another vendor or revise your design. Remember, just because you specify a tolerance on a drawing doesn’t mean that it can be done.
- Surface finish — Do you require an 8RMS surface finish on a part because that’s where a seal makes contact with it? If a vendor claims they can do what you need, make sure that they have the capability check.
- Inspection services — Does the vendor have some sort of metrology department? Do they have the equipment necessary for inspection? Surface plates, gauges and a CMM machine should all be standard. If your parts need to be checked for concentricity or parallelism, can they do it and prove it with paperwork?
- Assembly services — Do you need someone to put your product together? Many vendors offer assembly services or will subcontract the work. Sometimes you may need them to just do partial assembly. Make sure that they can do it or know of an organization that can. If they are using a subcontractor, insist on transparency in the transaction.
- Color — If you specify Pantone #53B0AE (blue turquoise), and what you receive from them is a kind of close bluish color, you will be rejecting a lot of parts. At best, those parts have to be sent back for re-finishing. Worse, the unfixable ones are now scrap. Returned parts for rework slowly sours your relationship. This is true even if they are ones at fault. Try to avoid the situation altogether by making sure that they understand that you require exact color matches.
- Packaging — Can your parts be wrapped in newspaper and dropped in a box? Does each piece require its own plastic bag? Maybe each part needs a wax dip for protection. Establish ahead of time how the parts will be packaged for shipping. A vendor that produces fabulously precise parts that get destroyed during shipping is going to cause headaches.
- HazMat shipping — Hazardous material requires special shipping procedures by specially certified people. If you require a vendor to work with a hazardous material, they should be qualified to ship and transport it. However, don’t assume anything. Make sure that they can handle the job and select vendors based on their ability to prove competency. Otherwise, you will be waiting a long time for them to get certified.
- Life Cycle — Your part or product may be expected to have a 7-year life cycle. Will this vendor agree to provide service over this length of time?This is especially important in the case of unique components. Depending on the critical nature of your business, this may need to be hashed out via a contract. No company can guarantee their longevity, but there can be steps for adjustment should something happen in the future.
- Vendor Location — Consider the following: A US based vendor manufactures parts for an assembly that is assembled and tested in China. The finished and packaged assembly is then shipped back to the US for sale in the North American market. Parts have now been shipped to China and then again back to you from China. There are times when this is required due to costs or other criteria based on points listed above. But grouping vendors closer together can lower overhead, especially when there is not an ocean between them. Verify an overseas vendor is truly necessary before moving forward.
- Customer Service — Judge your interaction with prospective vendors: Do they respond within reasonable time limits? Do they have an attitude? Are they condescending? This line item may be unpopular with some people, but I wish someone had pulled me aside in my early days and given me this advice. So many times, I didn’t listen to my instincts when they were trying to tell me that something was “off” with an organization. The temperament and attitude you experience during early interactions is unlikely to change later. Behavior that is slightly unsettling now might turn into a very real issue after you actually start utilizing the vendor. Long absences in communication and being argumentative or discourteous are huge warning signs.
- Company Size — Don’t feel obligated to look for the biggest and most well-known vendor in any particular field. Newer and smaller companies are often faster and more competitive. Also, because they are looking to attract and keep new customers, they will often be willing to go to lengths that a larger organization may not. Larger, more established companies tend to depend on larger customers because of their own overhead costs.
Always be professional and let the vendors know that didn’t get selected for the job. It pays to be courteous and professional. The vendor you didn’t use today might be a perfect fit for a job in the future. In fact, let the losing vendors know you will consider them for upcoming work, especially if they are prompt in their communication.
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