CNC Grinding: Outdated or Overlooked?

Our founder Abe Savitzky’s expertise in surface and form grinding led to our company’s early success in tool and die making. Back in the early 1950s, form grinding was the new technology that enabled much more precise and durable stamping dies to be designed and built. But it was a demanding process that required both skill and finesse, and as time went by, it became more difficult to find people who could master it. Today, Wire EDM has all but replaced form grinding due to its automation and reliable consistency. So, is there still a need for form grinding? Most definitely. The key is in understanding how both processes work. Grinding occurs in three phases. The first phase, the cutting mode, happens when there is sufficient interference and pressure between the abrasive grit and the metal workpiece to form a chip, as in milling. This is how the bulk of metal is removed. The second phase, ploughing, occurs when the pressure is not sufficient to generate a chip, and the abrasive grit deforms, or ploughs, the metal to the sides, much like a farmer plowing fields. This removes a small amount of material and is used in semi-finishing operations. The last mode is rubbing, and occurs when the pressure between the abrasive grit and the workpiece is too low to even plough the metal aside. It’s used as a final finishing pass when excellent surface finishes are desired. When done correctly, grinding does not put excessive heat into the metal, so its metallurgical properties are maintained. Most experts agree that a properly ground stamping punch will have greater service...

Rob Report Subscribe via RSS Going Beyond the Blueprint: Case in Point

At RS Precision, our approach to creating value always includes “going beyond the blueprint.” Here’s one example which shows just how valuable this process can be. I met with an OEM who was looking to have a part produced domestically. They had been purchasing this proprietary cutting tool overseas from the German manufacturer of the highly sophisticated Fromag machine. As part of its manufacturing process, the OEM was using two Fromags to produce blind, internal slots in power steering units for the truck industry. And in order to keep up with demand, the OEM had placed an order for a third Fromag. However, they were experiencing ongoing problems with the German cutters—specifically, the cutter heads kept breaking off unpredictably. Not only did this result in downtime, but considerable—and expensive—collateral damage, since they needed to replace a number of damaged components along with the broken cutters. What’s more, the price of the imported cutters was high. So basically the OEM was looking for a domestic source that could produce a part that was not only cheaper, but more durable. RS Precision went “beyond the blueprint” by first inquiring about the grade of tool steel that was being used in the imported cutters, since different tool steels have different tradeoffs between wear resistance and toughness. It turns out the tool steel being used was T15 High Speed Steel, which has poor shock resistance—and was suspected to be the key reason for the frequent failures. We then made samples from three alternative tool steels that had better shock resistance. This exercise gave us experience in manufacturing the part. The OEM then tested...

Eliminate those headache jobs with a one-stop source—and a shop that thinks differently.

Oftentimes, subcontracting the manufacturing of a single part to multiple vendors delivers nothing but poor results. But there can be other, more profound advantages when dealing with a single source like RS Precision. A customer had been shepherding the production of a highly complex part through a number of different shops which ultimately resulted in a lot of fall out, scrap and unusable parts. The part, a vertebrae ring used in the bending section of miniature flexible endoscopes, featured some very intricate and fragile geometry and complex angular relationships. The multi-vendor production process looked like this: 1. The customer purchased the raw material. 2. The raw material was sent to a screw machine shop that produced turned blanks of about an inch long, which yielded about 10 pieces per blank. 3. The blanks were then sent to another shop that Wire EDM’ed the internal configuration and cut it into 10 individual pieces. This often resulted in angular misalignment between the interior and exterior features. 4. The part’s final stop was a machine shop that drilled .015 inch diameter holes. The part’s delicateness and lack of pronounced alignment features caused some drilled holes to be off location. As the “blame game” among vendors ensued, and the quality issues continued, the customer finally approached RS Precision. Perhaps by producing the part through a single source, the results would be different. The customer walked us through the entire production process so we understood the challenges. However, what we soon realized was that if we were to produce the part exactly as it had been done before, we too would have experienced the...

Lowest price or lowest total cost: What’s your company’s moneymaking strategy?

If all your company cares about is the lowest price, it may not be worth your time to read any further. But I would also suggest that you’re missing an important opportunity! I talk frequently about the value of partnering, but all too often find my words falling on deaf ears. The challenge is in convincing non-believers to regard their supplier relationships as strategic opportunities that can truly boost bottom lines. You may be thinking, “If the benefits of partnering are so compelling, then why isn’t everyone doing it? Good question! I believe it’s because some companies fail to focus on the important—and lucrative—benefits associated with reducing TOTAL COST, opting instead for the illusory—and limited—benefits of LOWER PRICES. And getting companies to consider working collectively with their supplier to reduce total cost oftentimes requires a leap of faith, one that abandons old concepts and policies. So, what are the tangible benefits your company can achieve by focusing on lowest total cost rather than lowest price? Your answers to the following questions may reveal that you are focusing mainly on price, and are overlooking a host of hidden costs incurred each and every day when using lowest-price suppliers: 1. Are you getting 100% on-time delivery and better than 99.5% good parts from your suppliers? If not, do you know what it’s costing you? 2. Can you skip incoming inspection with confidence? If not, do you know what it’s costing you? And if you’re finding defects that require MRB to disposition, do you know what it’s costing you? 3. Are you able to minimize your inventory by reliably bringing in parts...

When hiring the right manufacturing talent, 2 out of 3 ain’t bad!

When hiring the right manufacturing talent, 2 out of 3 ain’t bad! There’s nothing new about the shortage of skilled manufacturing help. An aging, craft-intuitive workforce has given way to automation and technology that have considerably softened the talent pool. Plus, there’s a public image issue that needs to be addressed—and rectified. But, when you do find yourself looking to hire the right person, take my advice… No matter the industry or the position, a hiring strategy that’s worked for me is: When interviewing prospects, thoroughly evaluate these three attributes: 1. Talent. Does the candidate possess the innate intelligence and skill set to perform the job at hand? And, how quickly will s/he learn to do so in an efficient manner? 2. Experience. How long has the candidate been performing the work that’s required? With what types of companies and/or environments? Does this experience include directing others? If so, what functions? 3. Chemistry. Do the candidate’s temperament and character traits align with the company’s culture? Is s/he a good fit who will work well with other team members? Then, rate each attribute using a scale of 1-10 (with 10 being the absolute best), and hire only 8’s or higher across the board no matter the position. But here’s a tip: the one attribute where compromise is possible is Experience. Both Talent and Chemistry are innate qualities. They’re inherent to the individual and, to a great extent, independent of experience. And, a person who rates highly in Talent and Chemistry can achieve the desired experience level over time. So, if Talent and Chemistry are good, I would allow Experience to...

Increase your part’s performance and value? Precisely!

This month’s Rob Report is guest-written by Robert’s father, Abraham Savitzky, founder and Chairman of RS Precision. Abe is one of the true pioneers of EDM, having purchased his first Elox sinker in 1960. Today’s markets for high performance instruments and devices require manufacturing innovations to achieve both performance superiority and cost advantages. When used knowledgeably, EDM can play a key role in producing products with a clear competitive edge. Here’s why: Design freedom. Unlike conventional machining, EDM allows design engineers to have almost complete freedom of shapes and configurations for the component’s features. This can be used to gain performance advantages, as well as to differentiate their products from their competition. Consistency and Repeatability. Highly irregular shapes can be produced very accurately by EDM. Because fresh electrodes are used for every piece, EDM eliminates dimensional variations experienced in conventional machining due to deflection of the tool and/or part, or changes in surface finish due to worn or chipped tool edges. Material-friendly. EDM is often used to machine the most difficult-to-cut materials—any material, in fact, that is electrically conductive. Cutting internal threads and fabricating intricate or complex shapes into extremely hard materials are routinely done. With no physical contact between the electrode and work piece, EDM is used to cut intricate configurations in parts too small or fragile to clamp firmly enough for conventional machining. Cost effective. The cost of EDM is dramatically reduced when multiple parts are processed simultaneously. EDM also affords significant savings in cutting tool and deburring costs. Moreover, micro-machined parts and features too difficult to do conventionally can often be produced easily and cost effectively...