Shop Solutions: Swiss-Made Tooling Optimizes Swiss Machining
Due to a continuous surge in work, Swiss Automation (Barrington, IL) recently opened a second plant in Cary, IL, to handle its steady reoccurring production jobs as well as those involving blanket orders spanning years at a time. Part volumes for the new second facility can be for as few as two pieces per job, which is rare, to hundreds of thousands of parts being produced by multiple machines running in 24-hour shifts for years until order completion.
To meet its production needs, Swiss Automation’s Cary shop houses 26 of today’s most advanced Swiss-style CNC turning centers. With increased rapid-traverse speeds and machining precision, the machines deliver continuous production, fast part cycle times and superior surface finishes. However, to really benefit from such high-end equipment, Swiss Automation realized early on that extremely precise tooling is a must.
Larry Kott, plant production supervisor for the Cary facility, has been with Swiss Automation for 11 years. And as long as he has been an employee, the company has relied on tooling from Rego-Fix Tool Corp. (Indianapolis, IN) for its 90 Swiss-style machines in the Barrington facility. When the time came to tool up the machines in the second plant, he opted for all Rego-Fix tooling—ER collets and holders/sleeves—for all of the shop’s Citizen brand Swiss-style machines, as well as its two Miyano chucker-style CNC turning machines.
According to Kott, the precision of the Rego-Fix tooling is critical for holding part tolerances and generating required surface finishes. Plus, the tooling helps shorten machine setup times and provides dependable performance and long working lives.
Practically all of the parts at the Swiss Automation shop in Cary are made from bar stock that has been centerless ground to size within ±0.0005" (0.013 mm) or drawn bar stock that is within ±0.001" (0.03 mm) in size. Part materials range from brass, 304 stainless, 316 stainless and leaded materials to Inconel, titanium, copper and aluminum.
Of all the high-production jobs at Swiss Automation, most of them are internal parts for hydraulic assemblies and systems. The shop’s customers include large hydraulic OEMs whose products are then used in such applications as heavy off-road equipment, lifting systems, single-use medical connectors, cable industry connectors and automobiles.
Part processes at Swiss Automation include turning, milling (end and face milling), drilling, boring, internal grooving and angle drilling. The facility’s machine sizes are 0.6, 0.8, and 1.3" (16, 20, and 32 mm), and the two chucker-style machines accommodate diameters up to 2" (51 mm).
Swiss Automation refers to the parts it produces as raw because each one is 90% complete when it leaves the shop. Upon receiving parts, customers will then perform any minor surface finishing or assembling operations. Also, in many instances, the shop will produce families of parts, as well as multiple mating components.
While overall part tolerances can average ±0.003" (0.076 mm), specific part feature tolerances can be quite stringent. For instance, most bore diameters must be held to within ±0.00025" (0.0063 mm), and required total indicated runout (TIR) tolerances can be as tight as ±0.001" between part inside diameters (IDs) and outside diameters (ODs). But the challenge of holding required tolerances really increases when dealing with small parts made from bar stock measuring only 0.630" (16 mm) in diameter or with those parts involving long tool overhangs.
“When you have a small diameter tool sticking out of a holder as much as 2" and running at a high spindle speed, you better have reliable, highly precise toolholding with extremely low runout. For us, maintaining tolerances under those conditions is definitely easier with the accurate toolholding of our Rego-Fix collets and holders,” said Kott. “In addition to part tolerances, the precision of the tooling is mandatory for achieving our part surface finish requirements, and those can vary from Ra 32 to Ra 63 and better.”
Rego-Fix standard ER collets provide a TIR of 0.0004" (0.01 mm) or less over their entire clamping range and accurately clamp tool shanks ranging in size from 0.0079 up to 1.3386" (0.2 up to 34.0 mm) in diameter.
The fast rapid traverse and maximum spindle speeds of today’s advanced linear-motor Swiss-style machine tool technology have drastically reduced Swiss Automation’s part cycle times over the years to an average between 20 seconds and 2.5 minutes. The shop’s latest Swiss-style machines also allow for in-place tool indexing that reduces non-cut times by eliminating the need for moving the tool away from the part for that operation. Most important, the newer machines provide B-axis capability for angled drilling—another operation that, according to Kott, definitely requires the high precision of Rego-Fix tooling, especially when holes intersect with other cross holes.
Any part requiring cross, angled or standard drilling is done only with Rego-Fix tooling, said Kott. The shop uses the company’s ER 11, ER 16, ER 20 and ER 25 collets—as well as its ER 16/DM metallic sealed collets for high-pressure through-tool coolant and collet sleeves/holders, many of which are 1" (25.4 mm) in diameter. Every machine uses the tooling in their live gang tooling positions.
On each Swiss-style machine at Swiss Automation, there can be 10 positions on the turrets, and some of those individual positions can hold two tools for a total of 20. In some cases, machines are equipped with triple holders, so the total number of tools increases to 30, meaning three Rego-Fix collet holders will be used at one tool-turret position.
Kott described a typical Swiss machine setup: “For our normal M-style Citizen Swiss machine, we will load them with 9–10 gang tools—four of which can be live and use ER collets for drilling, cross drilling and spot centering. There are also three independent back-working stations, and if those are doing drilling, they too will have a Rego-Fix holder and collet. Machine turrets then provide nine usable positions out of 10, or they can be the type that holds double that amount. In which case, we will load 20 grooving and/or boring tools. On average, each machine can potentially have between 25 and 30 tool positions, all loaded with a Rego-Fix collet and sleeve,” Kott said.
Rego-Fix’s high-precision toolholders require a lot less “indicating in” during machine setups, which also contributes to shortening setup times. “We have never experienced any issues such as inconsistent holder sizes or excessive runout causing chatter or taper with the Rego-Fix tooling. We found tooling that works, and we have been sticking with it,” said Kott. ME
For more information from Rego-Fix Tool Corp., go to www.rego-fix.com, or phone 317-870-5959.
This article was first published in the September 2013 edition of Manufacturing Engineering magazine. Click here for PDF.