Zero defects, 3-Shift Production

Wiscon Products, Inc., Racine, Wisconsin, founded in 1945, is a family-owned and operated contract precision machining job shop that is aggressively investing in equipment and improving. “We’ve just had several years’ of growth, investing  more than 30% of our total sales in new equipment,” said Torben Christensen, president.

With a highly skilled workforce of 50 averaging more than 15 years with Wiscon, the company produces a range of flat and shaft type parts such as hydraulic components, powered hand tools parts, oil field parts—a very eclectic mix of complex parts and challenging materials, many automotive.

“Being competitive in these days is essential, yet more difficult,” Torben said. “Customer parts are more complex with tighter tolerances. They also want cost-effective analysis and competitive pricing.”

At Wiscon, three INDEX multispindles CNC lathes and six INDEX C Series automatic lathes occupy the shop floor and all are busy.

Wiscon seems to be doing a lot right. It operates three shifts, not only picking up 4 extra hours during the day but also increasing production efficiency because there is no start/stop and related warm-up time, first piece run-off and start-up procedures. Scrap rate also is reduced significantly.

The 6-spindle CNC MS52 features a 52mm (2-in.) bar capacity and 100mm (4-in.) chuck capacity. The INDEX open-front machine design concept is a result of the absence of the end slide tool carrier and the opposed headstock. This allows the integration of a load unload robot, and improves ease of set up and changeover significantly. It also offers unrestricted chip flow.

With six spindles and 12 tool carriers with optional backworking, the INDEX multispindle concept is well suited for producing complex chucking type parts parts in medium to high volume.

The heart of the machine is the spindle drum, with a three-ring face tooth coupling mechanism, pioneered by INDEX. Owing to a high-precision manufacturing process and the face tooth coupling, the machine is guaranteed to have the highest turning accuracy possible in a multi spindle machine.

Six independent spindle motors allow optimum cutting speeds for each tool and increase productivity dramatically. Almost all spindle positions offer two- axis or four- axis capability. Since most slides are capable of CNC contouring, form tools are eliminated, and standard single-point presettable insert tools are used in almost all positions.

The 12 CNC tool carriers—two per spindle--are designed in a space saving vertical arrangement and prepared for quick change pre-settable tooling. OD, ID or live tools can be used in any slide position. Up to three I.D. tools can mounted in a gang style arrangement on any one of the two axis slides, significantly extending the tool capacity of the machine.

One of the parts running at Wiscon is a steel automotive camshaft end-piece. The shop is making four different parts for the customer on several different machines in the shop.

“On this part, we run over 500,000 automotive camshaft end pieces on the MS52 with a robot unload/inspection cell,” Torben said. The parts are machined complete, deburred, cleaned, the thread poke-yoked, and put into a vision inspection system to capture 22 different characteristics. We inspect for 105 different print features with part positional tolerances of 20 microns. The result is zero ppm rejection rates from the customer. Zero. Every day,” Torben stated.

“We actually package these and ship these to China for our customer’s car manufacturing facility there. They are confident they can just put our parts in and they will be good.”

“Another company that had the job did it out of a saw cut blank, machining two sides then knurling. The part went through several operations and handling, resulting in unacceptable tolerance variation and bad quality. Labels on dunnage from other shops show how many times some of the parts had to be inspected and repaired before acceptance. It’s a shocking number. How do you make money on that?”

“Our quality range gets you a lot of credibility with the customer – I started as a supplementary supplier with this part, and we now have 4 parts from this customer.”

Just having finished up a full 3-day ISO certification renewal, Torben pointed out the quality management room, which includes a new Zeiss CMM. “We were getting to the point where we could not prove how good the parts really were, so we invested in the quality equipment.”

Wiscon develops the process for each different customer part, fully utilizing the productivity of the INDEX equipment. And it starts on the desktop.

“We use INDEX VirtualMachine process design and simulation software for at least 90% of what we do. We use it to develop cycle time analysis, and that has been highly beneficial. No CAM system is necessary or would tell us more.

“We found that the more time we spend with VirtualMachine to design realistic tooling for each step of a process, the process will be much more efficient and the parts much more accurate from the get-go. Production can happen immediately with faster start up times because we can fully optimize the process and cycle times before we cut a chip.” Another positive result of VirtualMachine is that Wiscon avoids using up to 12 hours of machine time trying out a new part process.

On one of the C100 automatic lathes, Wiscon runs square stock for a ballscrew nut. “With the C machine, we can maintain all the orientations. The part starts with a center hole, so it runs pretty fast—up to 4000 rpm on the tooling. For square stock or hex stock the INDEX bar loaders are the only ones that work efficiently and quietly,” said Torben.

With three 14-position tool turrets and identical main and counterspindles, the space-saving INDEX C100s are designed for fast, cost-competitive production of complex parts turned parts from bar stock from 30-42 mm diameter. Ideal for small to medium lot sizes, the three-turret machines deliver high performance within a small floor space.

Up to three tools can be at work simultaneously with both Y axes and backworking at the same time. And the counterspindle with linear-motor driven Z-axis can be synchronized with travel of turret 3. Counterspindle pick-up from the spindle is accomplished in just 1.5 seconds.

Because the C100 is configured to complete a wide range of parts, small to large batch sizes, Wiscon reports extremely high machine utilization rates, which allow the C100 to be very cost-effective. Parts can be unloaded from the main or counterspindle.

Simultaneous machining with two Y axes at the main spindle or a Y axis at the main spindle and also one at the counterspindle—each with 70 mm travel—gives Wiscon the option to divide machining operations for optimum machining efficiency and flexibility This freedom also is a key to reduced cycle times. For example, Wiscon can machine simultaneously with up to 3 driven tools for complete machining in a single set-up, including heavy milling, and backworking with up to 5 tools.

Picking up a recently produced part, Torben said “I feel the INDEX C100 is the only machine that could do this part, which is used by the solar industry--800 per day, every day of the week. It takes about 35 tools to make it complete. The part has a lot of detail, and many times the customer will change it on the fly. That’s why we find the versatility and quantity of the tooling on the C – up to 42 tools live or stationary – is key. We are now the customer’s largest supplier of machined parts.”

Another of the C100’s uses 34 separate tools to make a stainless part in a single setup-–half are live tools. “Not many pieces of equipment could handle that many tools, especially with that many live tools,” Torben said. “When you are using 34 tools, chip-to-chip time becomes very important; it’s less than 1 second each on the C100. This saves an amazing amount of time. That’s critical because the less time it takes for us to do that work, the more valuable our time becomes.”

Another part, a flash suppressor for an automatic rifle, is machined complete on one of the C100s. “In this case, we found it was better to slow the machine and avoid burrs rather than have to add manual deburring afterwards. Plus it improves control of the process, providing a level of consistency that otherwise would not be there.”

Deeply invested in INDEX equipment, Torben sees the return.

“INDEX really helped us over the years. We feel we selected the right partner to create a production capability that has grown and is now unusual in the precision parts industry.”