Machine Shop Brings Fresh Perspective to Challenging Parts
Fairchild machined this part from one thin stainless steel bar and from a thicker copper bar and then assembled them, saving the customer an estimated $45,000 per year. The customer originally asked for the part to be made by machining a single bar of stainless steel, but Fairchild's engineers showed the customer it could be made at a lower cost and assembled from two different pieces of metal. Photo courtesy of Fairchild Auto-Mated Parts.
Strong engineering support, design assistance lead to improved part designs
By Mark Langlois, Senior Editor
A customer approached Fairchild Auto-Mated Parts Inc. with a four-inch thick bar of stainless steel about six inches long.
"Can you turn this into a thin shaft on both ends with a four-inch wheel about halfway along the shaft in the center?" the customer asked. "It's a simple turning job. Can you carve this out of stainless steel?"
"Yes and maybe not," a representative of the Winsted, Connecticut machine shop replied. "We'll improve it. We can save you a lot of money."
The solution? Two parts– stainless steel and brass– that are machined and then assembled.
"It's not only that stainless steel is expensive. It's slower to machine," said Jonathan "Jake" Thompson, P.E., and president of Fairchild Auto-Mated Parts Inc., in a phone interview. By including brass, the reworked part saved the customer a significant amount of machining time and material. "It's a lower cost. The material savings and the machining time savings adds up," he said. Fairchild estimates the savings at $45,000 a year. "We're not removing all that stainless steel and throwing it away."
Bringing a Fresh Perspective to Each Part
The part now has a brass wheel on a thin stainless steel shaft. The brass wheel is sliced off a bar of brass, machined to size, and attached to the shaft. Fairchild turns the thin steel shaft out of a thin stainless steel rod. "Fairchild makes both parts and then assembles them, providing a part that is ready for insertion into the valve body used in an HVAC control system," Fairchild said on its website.
"Usually, we want to simplify things. We want to make it out of fewer parts and reduce assembly time. But, again, because of the disparity in the geometry of the two parts, it lent itself to a multi-part assembly," said Thompson during an interview with Design-2-Part at his Winsted, Connecticut, shop.
The valve component modulates cooling and heating water in high usage, high volume heating and cooling systems. The part makes minute adjustments that result in energy savings for the user.
"We make the shaft out of stainless steel, and this out of brass," said Thompson, pointing to the orange wheel halfway along the steel shaft. "It's as good. It does the job consistently and reliably, and it's a less expensive part."
Fairchild used both design and materials expertise to design the stainless steel/brass regulator shaft for the HVAC industry. To begin, Fairchild designed the unit as a two-piece assembly to lower costs. The company rough turned and then finish turned both parts. Then, they turned to their CNC Swiss turning center, single-spindle screw machine, press staking, and assembly operations to complete the part.
Holding a ± 0.001-inch tolerance, with a concentricity of 0.002 inch, a total run out of 0.001 inch, and a perpendicularity of 0.0012 inch, Fairchild built this part from a combination of T303 stainless steel and CDA 360 brass material. The shaft measured 1.300 inch in length and 0.8228 inch in outside diameter, and the finished part possessed a smooth, 32 RA finish. Fairchild then inspected all components and checked final assembly before shipping it.
Did Fairchild get the manufacturing job?
Today, Fairchild manufactures the part with a 6-week turnaround time. "Fairchild Auto-Mated Parts Inc., presently manufactures 35,000 to 55,000 regulator shafts per year for this client, building these high-volume parts within a quick, 6-week turnaround time," the company says on its website. "These shafts are currently used in HVAC applications throughout the world.
"With 68 years' experience behind us, we have a strong track record of supplying parts to any number of possible applications for any type of industry," the company continues, "from high-speed hand pieces for dentistry and jewelry to welded assemblies for aerospace; from cost-cutting parts for HVAC, to components intended for use in naval engineering and astronomy."
In Business Since World War II
Fairchild Auto-Mated Parts operates out of 15,000-square-feet of space in Winsted, Connecticut, with 26 employees and four engineers. The machine shop was founded in 1944, and has been run by the Thompson family since 1970. Jake's family bought the firm in 1981. The firm specializes in manufacturing custom, precision CNC machined parts, and has been ISO certified since 2000. Its last audit took place in 2016.
"The parts we are able to manufacture are essentially limited only to the specifications of your request. Our portfolio gallery serves as testimony to our adeptness at engineering and manufacturing," Fairchild reports on its website.
Fairchild (www.fairchildparts.com) serves numerous markets, including aerospace, electronics, medical equipment, musical instruments, hydraulic and pneumatic valve components, test specimens, and instrumentation, offering runs in quantities from 50 to 100,000 parts. The company operates 7-axis CNC Swiss turning machines equipped with magazine auto bar feeders that can maintain tight tolerances of up to 0.0001 inch. In addition to 7-axis CNC Swiss turning, Fairchild's services include CNC milling and high production screw machining. The company also offers staking, stamping, bending, vibratory finishing, assembly, packaging, stocking programs, product development, consulting, and testing.
"It is our commitment to providing excellent machining services that makes Fairchild Auto-Mated Parts, Inc. a favored supplier of ISO compliant, custom screw machine parts for diverse industries, manufacturing top of the line fasteners, fittings, gears, valves, and shafts," Fairchild states on its website.
Machining Advanced Materials
The company can machine Inconel, Invar, Iridium, Kovar, Niobium, Palladium, platinum, silver, gold, tantalum, Monel, molybdenum, and other difficult-to-machine metals, as well as more common metals.
Another example of its work is a latch bolt assembly used on missiles for the military. The company uses 7-axis CNC Swiss machining to make the part from 4140 steel, aluminum, and nylon, meeting close to 0.001-inch tolerances. Fairchild coined the seat to improve functionality. After assembling the part, Fairchild anodizes the part with a process common for military applications to give it an olive drab look, using electro cadmium and electro zinc formulas. The company produces roughly 35,000 of the missile latches per year.
In addition to working in metal, Fairchild can work in polymers, creating 3D prototype parts, if requested. Thompson said the company's formula for success isn't too complicated: quality at a competitive cost, plus "strong engineering support and design assistance."
"Their (the customer's) engineers can talk to our engineers," Thompson told Design-2-Part Magazine. "Because we're knowledgeable in metallurgy, in the strength of materials, in how to do the work, we talk to them about what they're trying to accomplish with the part. What we look at is 'How can you accomplish it better, at the most economical method of manufacture?' It's been a successful formula.
"We have many, many years of experience in the design of tooling, the selection of tooling, the marriage of tooling with the machinery that uses the tools," Thompson continued. "In other words, certain machines are effective at utilizing certain types of tools; whereas, they don't work as well on other types of machines. And this is married to the fact the company makes continuous investments in new technology, in new machine tools, and in new processes, so we do everything as well as we did yesterday and hopefully do it a little better tomorrow."
3D Printers Enable Quick-Turn Prototyping
In one example, a customer asked if they could take a part from drawing to prototype. The part itself would be used in a precision measuring instrument that would measure the thickness of coatings and platings. The final product would be aluminum, but the mockup would be ABS plastic. Once Fairchild printed the prototype using a 3D printer, the customer redesigned the part.
"The mockup helped them refine their design," Thompson said. "What we bring to the table is we invest in your design and we add our manufacturing and design expertise to optimize your part, its function, its value in terms of all desired features at the appropriate level of cost, if required or applicable. We have the ability, in certain cases, to do testing of a certain design, to confirm we're on the right track for endurance, strength, and wearability to confirm design."
The customer redesigned the prototype part again, leading Fairchild to quote the part three times. Thompson said he wasn't certain that Fairchild offered the lowest price, but it won the contract to manufacture it anyway.
"Our price might have been a little bit higher, but they went with Fairchild because of the relationship and the knowledge and exchange of ideas that went between their engineers and our engineers," Thompson said.
In another case, a customer brought Fairchild a part that a competitor had been making, and which kept failing. The part went into a large industrial valve. It had three pieces and the design was locked in. A wheel in the assembly kept breaking off, destroying the valve.
"We got samples of the previously manufactured parts. They told us the disk kept unseating. We analyzed the design and we decided we needed to redesign the part. We knew we had to control the tolerances, work locations, and finishes to a more critical level," Thompson said. "It resulted in a successful design." Thompson said that wasn't the end of it.
"They said 'We kind of believe you, but we need you to prove it,' so we made 40 or 50 samples and we designed and built a test fixture to test them," Thompson recalled. "The customer brought samples of the previously manufactured parts, and we tested them against the Fairchild-made parts. The Fairchild parts were approximately 80 percent stronger. The problem of disassembly just went away. We designed in a sufficient margin of safety. That gave them the confidence to go ahead and have us produce the part."
This technical information has been contributed by
Fairchild Auto-Mated Parts
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