Hard Milling Veterans: Little Lakes Machine & Tool
For Little Lakes Machine & Tool Co. Ltd. of Stratford, Ontario, the term “easy job” is not part of the day-to-day vernacular.
The company’s niche expertise in custom powdered metal tooling has presented several unique challenges that few other shops face, let alone are willing to take on. With approximately 80 percent of its work falling between the 55 HRc and 65 HRc range, Little Lakes’ easiest jobs would be considered a nightmare for many other shops.
The company started its foray into custom powdered metal tooling in the 1960s, after the establishment of a nearby powdered metal manufacturer. As their primary supplier, Little Lakes soon found itself growing alongside this manufacturer, expanding capabilities with changing trends and increasing challenges. In 1995, Little Lakes was sold to three long-standing employees, Gene Beehler, Jim Roth and Dan Roth who took over as owners of the company
“As far back as I can remember, the biggest key to our success in powdered metal tooling has been our ability to evolve with the times by staying abreast of the latest technologies as they’re made available,” says Jim Roth. “I can remember a time not that long ago when operators would spend several days producing elaborate tools on manual machines with nothing more than their hands, a calculator and plenty of ingenuity. However, today’s applications are far more complex and expectations are much higher.”
“The custom powdered metal compaction tooling we produce are put under a lot more stress than a typical mold, and as such require very high hardness and abrasion resistant tool steels. Additionally, interchangeability in tooling has driven the demand for better accuracy and finishes that eliminate the need for manual fitting.”
Powdered Metal Compaction Tooling
Compaction tooling is a unique process in which fine-grain metal powder is placed into a cavity and compressed under high pressures to form a net shape part. At this point it is a mechanically bonded (green) structure. The part is then sent to the sintering furnace where the part will be heated just below its melting point. This heating process converts the mechanical bond to a metallurgical bonded structure. Powdered metal compacting is frequently used in the development of power transmission components, structural shapes, brackets and can be found in anything from household blenders to aircraft.
Powdered metal tooling allows for easier alloying compared to many standard part-manufacturing and compaction tooling processes. This capability enables powdered metal manufacturers to develop broader alloy compositions than many other manufacturing methods.
“Manufacturers requiring high-volume, hard milling part production typically find compaction tooling to be a fast and cost-effective solution based on its ability to form finished parts straight out of the press, often times with no secondary operations required,” says Jim Roth. “From the compaction tooling perspective, this makes our role in the process that much more important. We have to ensure that the accuracy and finish is perfect with absolutely no further machining required. Typical punch to die clearances are 0.0005 inches, if this isn’t held then the powder can slip between the cracks of our tooling and cause significant damage that greatly reduces tooling life span. As such, our applications require high-performance machining capabilities to ensure that the accuracy and finishes are there each and every time.”
High-Speed Hard Milling
In 2003, Little Lakes decided to stay ahead of the technology curve by researching some of the latest high-speed, high-precision hard milling machines. The company began by focusing on reverse-engineering part geometries of several desired applications in order to determine the required machine specifications. Little Lakes used these findings to develop a test-punch application, which was produced on its current machinery as a control group and later sent to five machine tool manufacturers to gauge performance.
Of the five manufacturers Little Lakes approached, Makino’s test part was the first to arrive. Using a V33 vertical machining center, Makino was able to reduce the total cycle time from approximately 26 hours to just 4 hours. The accuracy and finish qualities produced straight out of the machine were close enough to final spec that the company was able to completely eliminate previous EDM procedures and associated electrode production. Based on these results and previous experience, Little Lakes purchased the V33 without hesitation.
“Our local Makino distributor, Single Source Technologies, understood we were new to the high-speed hard milling world and assisted us in developing toolpaths and choosing the appropriate coatings and cutter technologies specific to the V33,” says Jim Roth. “With their help, we’ve been able to produce tolerances of plus or minus 0.0002 inches on a daily basis, worry-free.”
Breaking In to New Markets
Keeping up with the latest technology trends has also been driven by new business opportunities. Little Lakes was approached by a potential customer in 2006 looking for a manufacturer with the capabilities to produce a punch for a new portable photovoltaic film panel. The application featured hundreds of micro-scale half-spherical sockets used to hold tiny silicon beads.
“We had never produced compaction tooling as small and intricate as this before, but the opportunity was exciting and offered us an open door to expand our opportunities into a new and rapidly growing market,” says Dan Roth. “Based on the continued success of the V33 and outstanding service we received from Single Source Technologies, we decided to invest in a Makino V22 vertical machining center with a robotic cell for unattended machining of powdered metal tooling over nights and weekends.”
The design of the V22 vertical machining center includes several key technologies to eliminate vibration, rotational deflection and thermal distortion, ensuring precision, accuracy and reliability in long cycle time die and mold applications. Its 40,000-rpm spindle includes Makino’s patented core cooling and under-race lubrication systems for repeatable micromachining tolerances.
“The male side of the solar panel tooling alone required 21 days of uninterrupted milling,” says Dan Roth. “To prevent power outages from ruining over two weeks’ worth of work, we would have to purchase an uninterruptable power supply for the V22 itself.”
Equipped with Makino’s Hybrid Automatic Tool Length Measurement (ATLM) system, the V22 vertical machining center has provided Little Lakes with extended reliability in long run time applications. The machine’s construction features integrally casted slideways and no overhangs, providing excellent rigidity and damping characteristics for improved accuracy and extended tool life. In one case, a 0.1-mm (0.0039 inch) diameter ball endmill ran for 16 hours without any breakage
“When it comes to repeatable accuracy and surface finish in hardened materials, no other machine on our shop floor can outperform the V22,” says Dan Roth. “We’re able to hold tolerances of plus or minus 0.0002 inches for weeks at a time.”
Reliable Unattended Machining Capabilities
Little Lakes’ System 3R robotic capabilities were also integrated with the V33 vertical machining center to assist with all applications requiring more than a single shift of processing. Doing so has enabled the company to avoid increased spending for the additional manpower and energy consumption that would otherwise be required to keep the entire facility running three shifts a day.
“Our automated capabilities combined with Makino’s reliability are not just a relief for management, but also those on the shop floor who can start a job on Friday and enjoy time with their families over the weekend,” says Dan Roth. “And while these machines typically run two shifts on week days and unattended over the weekend, we can come back on Monday morning with finished jobs that require little to no additional work before being polished or sent to the press.”
The automated cell features a robust 20-position rack for a variety of applications. Working closely with Single Source Technologies, Little Lakes has optimized the cell for full processing, roughing and finishing, in its custom applications. This approach has enabled operators to perform all setups offline without interrupting machining processes.
“A good portion of our business involves the re-facing (re-cutting) of tools, which requires manual face grinding of damaged areas before entering the machine,” says Dan Roth. “By giving operators the opportunity to step away from their machines, we can turn around these applications in just a day or two. This has given us an upper hand in winning this type of business.”
Diversifying EDM Capabilities
Little Lakes’ most recent Makino investment came in 2008 with the purchase of an EDNC43S sinker EDM. “The EDNC43S was initially purchased for an aerospace customer that required indexing capabilities and fine finishes and hard milling in aluminum applications,” says Dan Roth. “What we discovered was that it also provided excellent quality in applications featuring long vertical depths, where we were limited with our previous technologies. With the EDNC43S, surface finishes are consistent throughout.”
Makino’s High-Quality Surface Finish (HQSF) technology enables the EDNC43S to maintain improved electrical conductivity for more consistent discharging and spark diffusion. As a result, Little Lakes has reported better surface finishes, faster processing and longer electrode life than any previous sinker EDM machine.
“The EDNC43S improves our sinker EDM capabilities across the board,” says Dan Roth. “The quality we’re producing has excluded or reduced polishing in all applications, allowing us to deliver faster with better quality than ever before.” Based on the success of the EDNC43S, Little Lakes decided to expand their EDM capabilities in 2011 with an investment in Makino’s latest sinker EDM technology, the EDAF3S.
Promoting Quality and Dependability
“Little Lakes Machine & Tool represents quality customer service and dependability, and we want to keep it that way,” says Dan Roth. “We can’t uphold this reputation if we don’t expect the same out of our machine investments.
“Between our Makino technology and Single Source Technologies’ service and support, we’ve become a one-shift shop that can produce two shifts’ worth of finished products. This is made possible by our highly skilled employees who are constantly challenging us with new ideas and tooling and process innovations on a daily basis.”
Little Lakes is now looking to use its knowledge and expertise for additional growth by expanding its customer turnkey services, adding yet another benefit for customers of these hard milling veterans.
Little Lakes Machine & Tool