Pro Tips - Issue #42
What type of shop is your shop?
The last newsletter was about thread depths. This time we are going to talk about different types of shops and finding the right fit for your company.
What type of shop is your shop?
Not all machine shops are created equal - nor should they be. Some are good at incredibly high-precision parts measured in ten-thousandths of an inch. Some are good at spitting out large quantities of parts quickly with low tolerances and cosmetic requirements very inexpensively. Some specialize in production where new part numbers are rarely introduced and rather focus on dialing in the process of making the few parts they make very well. This type of shop might choke if you asked them to turn around a prototype in a couple of days. Other shops specialize in quick turn prototypes and have the processes, people, and equipment in place to do this well. But don't ask them to make thousands of the same part because they might not be set up well to control the process of making that many parts repeatable. Some love to cut hard metals while others wouldn't know where to start. Some are real experts on turning and cannot mill a part to save their life.
I have realized over the years that one of the most important things that a customer can do is to really learn about what your vendors are good at. What type of shop are they? What type of work do they like to do? What don't they like to do? What do they believe their strengths are and what do they identify as their weaknesses? Even companies which on paper (or more likely on screen) might look like they have virtually identical capabilities may have completely different focuses and may not be at all suited to certain types of work. Identifying which shops are comfortable with the work you need done is a critical first step in developing a successful relationship that will be profitable for them and allow them to support you well.
A few months ago we had a vendor who had a good history with us utterly fail on a part we asked them to make. They quoted the part with a fair price and were eager to take on the work. But after receiving their First Article part, we were appalled at how bad the part was. The tolerances were not held and the cosmetics were atrocious. We immediately had them come visit us and talk about this part. They admitted that they weren't very good at parts like this one and not because it was complex geometry or a difficult material. Their decades of experience were primarily machining structural aerospace parts - the kinds with mostly +-.030" tolerances roughly machined and finished with an air-driven Scotch-Brite wheel to blend all the surfaces so it looks decent. What they were attempting to make for us was a medical device part which was aluminum with pretty basic 2.5 axis features, +-.005" tolerances, and very high cosmetic requirements. This was the kind of part we can do all day long in our sleep because we have developed years of experience and implemented processes to control those types of requirements. They didn't have some of the tools that we would consider essential to machine a part like that. Take edge breaking in the CNC machine for example. We often use edge break tools with only a .06" diameter or smaller so we can machine very close to other features while we are machining a .005-010" edge break. It is standard practice for us. The smallest tool they used for machining on an edge break was 1/2" diameter and normally they don't even machine the edge break - that is what files and grinders are for. We were dumbfounded when we learned this. They were dumbfounded to hear that we used .060" tools for such a purpose. This underscores that it just wasn't the right type of part for this shop. They are a good company with a good reputation and are very nice people. I am sure they do a great job at those structural aerospace parts they make so many of - in fact probably way better than we would at Pro CNC. But we didn't do a good enough job at identifying their strengths when we signed them up as a vendor, and clearly they didn't do a good enough job vetting this project when they were bidding on it. In hindsight we shouldn't have sent them this part to them to bid on, and if we did, they should have no-bid the job if they looked at the requirements closely and identified that they weren't strong in the areas this part required. It should ultimately fall on their shoulders to accept work that they will be successful at, but we can certainly help them out by asking the right questions up front and set them up for success. The silver lining to the story is that we had enough lead time to recover without affecting our customer's delivery date at all and we also learned a good lesson about managing a value stream more effectively which makes Pro CNC a stronger company.
So what questions do you ask your shops? Can you explain what they do well and what they don't do well? How confident are you that the work you are about to place with them is a good fit and they will be successful with it? Have they quoted a price much lower than other shops? If so, maybe they don't understand your true needs. (See our Whitepaper on this very topic in the Apple iBook store.) If you don't believe your company is strong in this area, I'd suggest you make an appointment to go sit and have a good talk with your vendor and really learn about them. They will appreciate you wanting them to be successful with the work you place, and your company will be more successful with better performing vendors. It may seem like an investment of time you can't spare, but believe me, it will take a lot less time than trying to recover when a job goes poorly. And if you aren't sure you have the right type of vendors for your work, give us a call. I can assure you that we will let you know if your part isn't a good fit for our strengths.
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