Major Medical Products Manufacturer
Relies on Makino VMCs and RAM EDMs

In the medical manufacturing field, an entirely new industry is evolving around micro-manufacturing. Items being designed are intricate, high-tolerance and high-quality parts, such as the leads that connect to life-saving devices such as implantable defibrillators and pacemakers.

Guidant Corporation, a global leader in the design and development of cardiovascular medical products, is a leader in micro-manufacturing technology. This is particularly true at the company's St. Paul, Minnesota, Model Shop for Advanced Manufacturing Engineering in Cardiac Rhythm Management, which has grown at a rate of nearly 46 percent, and will double in size over the next year.

Susan M. Sackman, model shop group leader, says the features and parts they are micro-manufacturing require such tolerances as 0.0002 inches, with absolutely no variance, over as much as a six-inch flat piece of 420 stainless steel. "We have come to depend on vertical milling and sinker EDM machines that can give us the best tolerances possible. We set out to acquire the best machines to meet our demands.

"We acquired two new Makino V33 VMCs to cut copper electrodes for two EDGE2S RAM EDM machines, which are dedicated to burning lead fixture molds for our various products. We also use the V33s to hard-mill steel molds and small, delicate ceramic leads. We need machines like Makino that we can count on to hold tolerances, quality and surface finishes. We just cannot get that micro-manufacturing quality in older technology or competitive equipment."

Guidant Races to Market [back to top]
Sackman heads the model shop which manufactures fixtures, dies and molds for all of Guidant's manufacturing locations through the shop's full capability operation, where they do everything except fabrication. Most importantly, Sackman is not just some corporate businesswoman trying to lead a tooling department. She is just the opposite; she is a toolmaker.

"I started my career as a toolmaker, went to technical college to get a degree, and then went through an apprenticeship program and got my journeyman's card," she says. "I liked the business side of machining, so I went to college and got my bachelor's degree in business management, and my master's degree in organizational leadership. I enjoy the business leadership side of manufacturing, but my experience and knowledge were built on a foundation of machining technologies.

"As an employee-owned company, with an unsurpassed culture, each person at Guidant understands that every project affects part of their company. We have a lot of demands and tighter schedules than most operations would face. It is a race, and throughput time and lead-time in our model shop is everything in order to beat our competitors to market. The quality and dependability of Makino helps us make the difference in saving people's lives."

Measuring Results [back to top]
While most operations measure machining success on cycle time reduction, Sackman says Guidant uses a computation based on "work orders completed." This formula factors cycle time reduction, throughput, unattended machining time, productivity gains, reduced benchwork and reduced rework into the equation.

"A mold would historically take us eight to 10 weeks to build. We are now building them in four," says Sackman. "We ship them to our customers, who are the engineers at different Guidant locations. These molds are used to produce the tips of critical cardiovascular component leads that connect the human heart to our pacemaker or defibrillator devices.

"Acquisition of the Makino equipment is also one of the main factors in decreasing our lead time and enhancing our 'work orders completed' formula. In 1999, our average lead time was 30 days. Beginning last year and continuing this year, we are down to 17.9 days. This drastic cut is really a money-saver for us."

That formula also includes a calculation of return on investment (ROI), which Sackman says was greatly exceeded through the acquisition of the Makino equipment. "The Makino V33s we have operated for more than a one year period," says Sackman. "The capital investment that we made was calculated at an ROI that proved the Makino machine paid for itself within the first six months of operation. By the end of the first year, I had saved twice that amount.

"Our accounting department likes a five-year payoff. We are 1000 percent ahead of that schedule on the V33s.

The same concept is true for the EDGE2S machines, which paid for themselves within one and a half years. By making the right initial investment, it may seem like more, but you can pay it off so much more quickly."

Making The Right Choice [back to top]
Guidant sent out some test samples to Makino and a number of competitive machine manufacturers to mill and burn some molds. Sackman says the results were not even close.

"The machining manufacturing industry is putting out great machines. But Makino definitely has distinct advantages over competitors, which makes the decision to buy these machines a little bit easier," says Sackman.

"We support a number of different projects with high-speed machining and making electrodes— such as milling fixtures and support tools for general manufacturing production line assembly devices.

"One thing that we strongly considered was whether the machine will be as effective and productive on our shop floor in two or five years as it is today. When you have an 8,000-rpm machine, you are very limited. When you have a Makino that goes 30,000-rpm, like the V33, then your operation can really become efficient. And, because we primarily mill and use copper electrodes, the outstanding EDM part quality produced on the EDGE2S is outstanding—just awesome."

Installation and training were also key factors in acquiring the Makino machines, according to Sackman. "Installation was great, and they helped train us from the time we ordered it, to the time it was up and running. Then they were checking with us after that to help ensure our success. I cannot say enough good things about the 'Technology Transfer' training from Makino.

"Because of this training and active support, we are better able to determine which jobs should be milled and which should be EDMed. This is a great aid to our operation, and a huge cost and time savings. Our customers love our molds. But, fast is never fast enough. We are able to keep up on technology through Makino to provide even better service for them.

"Makino's 'Technology Transfer' training was a primary factor in our selecting the V33 vertical machining centers we purchased," says Sackman. "While they have technologically advanced, 30,000-rpm spindles, you need the proper training and support to make them a valuable machine to medical micro-manufacturing. "Without the 'Technology Transfer' that Makino offers, you would only get the performance results of a machine with an 8,000-rpm spindle.

"Other companies simply are not offering that level of training and support. And if you do not have knowledge on how to use your equipment in the most effective way, you are wasting your money."

Achieving Results [back to top]
Model mold maker Dave Sederberg says Guidant utilizes copper electrodes in its processes due to the complexity of its products. "We need to burn to a high-glaze surface finish, and we get phenomenal results and extreme accuracy with copper," says Sederberg. "The shapes that we are burning are very small and intricate, and with the V33 we can actually cut in copper and get the high shine mirror electrode finishes.

"There are a multitude of diameters that need to seal, with pressure constraints. There are insertions and retraction forces the molds have to meet, holding up to 1,000 pounds of pressure with no tolerance variance. It is much easier with a copper electrode to maintain the level of mold quality tolerance. We use a 0.50 mm ball cutter on the V33 for parts that require 0.0005-inch tolerance holes and need a 0.2 micron glaze finish. Copper has minimum flex when burning. Even with high-grade graphite, we will still get a little bit of flexing with electrodes that are about 0.01 inches wide."

Guidant demands production of electrodes for molds that produce high-quality finishes and require no benchwork. "Any benchwork at all will not allow our intricate parts to achieve specification," says Sederberg. "We are simply not able to polish, as this potentially deforms the accuracy of the mold that was sought in the first place. And these accuracies are also vital for a shiny finish, which is going to produce a clear looking part that is perceptually important to patients in the medical industry."

Guidant also produces drug collars, which require complex molds that produce parts to control medicinal dosing. "The collars have a large number of fine details and very small parts—some so small they have to be inspected by microscope," says Sederberg. "The electrodes will burn the same size regardless of surface area because the Makino EDM will sense details and make adjustments, which eliminates rework on parts and maximizes unattended machining time on jobs that take up to 50 hours or more to burn.

"Guidant Corporation's Puerto Rico plant does the injection molding, but R&D and the manufacturing of the molds occurs here in St. Paul. The real advantages with the Makino V33 and the EDGE2S machines are that they work so well together. We are able to machine our electrodes in a day or two, which would have taken a week previously."

Value-Added Machinery [back to top]
Maintaining quality internal technology is important to Guidant preserving proprietary secrets as well as enhancing cost and speed. Sackman says that Guidant understands the need to invest in high-technology equipment, as they are now able to save nearly 30 percent of outsourced costs by manufacturing work internally.

"Our overall goal is to not outsource more than 20 percent of the model shop work. And right now we are close to achieving that," says Sackman. "Having equipment like Makino allows us to get jobs done faster, which means our on-time delivery is much better. That is something that we had struggled with in the past, and Makino has helped us achieve better goals in that area. Our previous goal was 90 percent on-time delivery. We are now 95 percent with Makino, and we hope to surpass that."

"In the past two years since we have gotten the V33s, we are funneling a lot more work through our shop than we used to accomplish. One of the things we learned through the 'Technology Transfer' class at Makino is the theory of how to approach our future. Operators on the other machines in our shop are coming to the Makino operators to ask about specific applications. Makino has been a really good investment."

One example of micro-manufacturing was a request to produce a 500-piece run of an insulator for a pulse generator that needed a high resistance to electricity because of current. With the Makino milling machines, Guidant decided to use a delicate ceramic that was 0.020 inches thick with slots 0.01 inches deep and features and details of 0.002 inches. They found a solution for its engineering group over a single weekend with the V33.

"Makino Die/Mold Technologies has been an asset for consultation," says Sederberg. "We have contacted them numerous times, and they have come through quickly. We also had some burning issues where we were meeting our maximum tolerance on the cylindricity of a burn, but we wanted to get something a little bit better.

"We talked to the EDM applications specialist at Makino Die/Mold Technologies in Auburn Hills, Michigan, one afternoon, and the next day he had some new orbit strategies for us. Our cylindricity was almost 0.0005 inches over the cylinder from the high to the low in that range, and we got it down to 0.0001 inches or less with the different orbiting strategy using the same electrodes. We do not have to worry about the work we put out for the company because we have Makino behind us."

In Guidant's view of the ultra-competitive medical device marketplace in which it operates, the company has proven that value-added services do have an incomparable impact on business. Equipment speed, quality and versatility are dependent on making the right choices for the right reasons. And in the world of micro-manufacturing, there is even less room for error.

For additional information about Guidant Corporation products or processes, visit www.guidant.com. Or, for more information about the Model Shop Group for Advanced Manufacturing Engineering at Cardiac Rhythm Management in St. Paul, Minnesota, and its use of Makino machinery, contact Susan B. Sackman at 651-582-2125, or at susan.sackman@guidant.com.

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