Sourcing Spotlight: FAQs for Selecting a Precision Machine…

Sourcing Spotlight: FAQs for Selecting a Precision Machine…

Feb 22, 2016

“Sourcing Spotlight: FAQs for Selecting a Precision Machine Shop”

By Del Williams, Design-2-Part Magazine

Answers to frequently asked questions can help OEMs find a reliable CNC machine shop for high tolerance work that is also competitively priced 
In industries like aerospace, defense, and medical, finding a CNC parts manufacturer capable of delivering the necessary quality, fast and reliable delivery, and competitive price can seem an elusive combination. It is akin to discovering the rare five-tool player in baseball that can hit for average, with power, field, throw, and base-run that doesn’t have a record-breaking contract.

Fortunately, such precision shops do exist. The difficulty, however, is in finding a shop that will actually deliver all that it promises in reality, and not just on paper.

Muddying the water, CNC shops – whether reliable and skilled, or not – all claim to deliver all of the above and more. Many have the same type and quality of machining equipment, but that alone doesn’t make for consistent parts, every time. Quality standards such as ISO and AS certifications go a long way, but these are also not enough to separate the best from the rest.

And then there is price. While not as important as quality for industries such as aerospace, defense, and medical equipment manufacturing, if the choice is between parts manufacturers that on paper appear similar, it will become a determining factor. But if the price is too good to be true, it probably is, and the result can be sub-par quality, missed deadlines, higher total overall costs, failures in the field, damage to reputation, and even litigation.

So how can OEMs choose the right shop for parts? While there is no magic bullet, the answers to a few FAQs will go a long way toward selecting a CNC machine shop that can deliver the requisite combination of consistent high quality, speedy delivery, and competitive cost.

For high tolerance work, how do machine shops ensure perfect quality every time?
”Perfect” quality means that when an OEM places an order for parts, they will be within the tolerances specified. These tolerances can be 0.0001 inch and tighter, and they apply to straightness, hole size, outer diameter (OD), inner diameter (ID), and other size/shape specifications.

“Industries such as medical, aerospace, or defense require ‘perfect’ quality because you can’t have one part compromising the quality of the assembled system,” says Gary Romig, founder and CEO of Summit Steel and Manufacturing (summitsteelinc.com), a metal component fabrication provider in Reading, Pennsylvania. “If one part goes into an assembly of 100 parts, and 99 are perfect, the single imperfect part can prevent product assembly or render the product defective and undeliverable.”

Quality is usually measured in rejection rate, measured in parts per million. Today, the acceptable rate of rejection continues to drop lower, heading toward the ideal of zero.

To produce a perfect part each time, CNC machine shops look for ways to continually improve and maintain tooling, check fixtures, and upgrade to the latest, state-of-the-art equipment.

Each new generation of CNC equipment, after all, is typically more precise, programmable, and faster than the one that preceded it. Summit Steel, for example, budgets a sizeable portion of its revenue to routinely upgrade to the newest CNC mills, lathes, and Swiss screw machines.

CNC machine shops also look to acquire the highest quality metals and materials, since these workflow through the shop with fewer problems and produce higher quality components. Purchasing from prime sources with full traceability is also essential to ensure that quality begins with the raw materials.

Another way parts manufacturers maintain consistent quality is by investing in automated inspection and measuring equipment, such as coordinate measuring machines (CMM). Instead of manual measurement, which can be lead to inconsistent results, CMM utilizes computer-controlled touch probes to measure various aspects of a part.

Although perfect quality does come at a price, the higher price up front often saves money on the back end.

“For the OEM, perfect quality means they don’t have to reject the part, send it back, have it reworked, and delay their deliveries. For the OEM’s customer, it gives them assurance the product they purchase will work as promised every time,” says Romig.

How do I select a parts manufacturer with confidence they will deliver the quality they promise?
Auditing a machine shop and visiting the facility can provide an OEM with a great deal of assurance that a high tolerance parts manufacturer will be able to deliver a high-valued part every time.

Check for capacity availability, quality control, and testing systems (including how often the instrumentation is re-calibrated). The OEM should also evaluate the staff they meet in regards to how well they understand their quality needs.

In addition, ask about the equipment. As mentioned, precision machine shops should be continually investing in the latest equipment. At Summit Steel, this is done on a tightly regulated, automatic schedule of replacement.

Finally, cleanliness and shop organization can also be major indicators of the quality of the overall operation.

“When an OEM visits a machine shop, they should find it clean, organized, and precise,” says Romig. “It should be a state-of-the-art facility with the latest equipment. Quality shops welcome audits and visits from potential customers.”

What is the best way to ensure on-time delivery without fail?
Most delivery date delays are caused by shipping to multiple companies and locations for secondary operations, such as part finishing, forming, coating, welding, and assembly. Any errors along the way only increase the delays, particularly if a vendor blames a sub-contractor for the error and will not take responsibility for correcting it.

For this reason, more parts manufacturers are adding ancillary services that go beyond traditional machining techniques.

“The surest way to guarantee on-time delivery is to work with a vendor that offers a full range of primary and secondary machine shop services, that will take full responsibility without dropping the baton,” says Romig, who has expanded Summit Steel’s in-house offerings over time to include laser cutting, centerless grinding, powder coating, welding, and assembly, all at the Reading plant. “When all necessary processes are done under one roof, rather than shipped out to a series of vendors, delivery times can often be cut by a month or more.”

Often, speeding turnaround and reducing costs simply comes down to working with a machine shop that spends the time to ask questions and really understand the customer’s expectations.

“Speeding turnaround is often directly related to asking all the correct questions up front,” says Romig, whose company typically ranges from 95 to 98 percent on-time delivery each month. “There are always different ways to achieve the blueprint tolerances, but sometimes unique tolerances are required for a part, sometimes not. Asking the right questions saves lots of time when it’s time to run the parts.”

Are there other ways to keep costs down, without compromising quality?
When it comes to CNC machine shops, sometimes bigger is better.

Smaller machine shops typically buy in small quantities from metal service centers that include a middleman mark-up. Some larger metal fabricators, on the other hand, have the buying power to purchase large quantities direct from the mill. These savings are then passed along to the OEM.

“Buying direct in bulk from metal manufacturers, not distributors, removes a whole layer of cost mark-up from the buying process,” says Romig. “It can translate into a savings of several percent even before the part is made.”

Del Williams is a technical writer based in Torrance, California.

More Efficient Sourcing of Machinery Parts is Key to Avoiding Unscheduled Downtime

By Ed Sullivan

Sourcing replacement parts from tool and die makers or machine shops can be much more efficient than relying on equipment OEMs. Those who’ve had a production line go down due to a lack of spare parts know how frustrating it can be to rely solely on equipment OEMs for replacement tools.

Since OEMs are primarily in the business of designing and building production equipment, they are often not in the best position to spend the time or capital required to provide an adequate inventory of replacement parts or assemblies. At the same time, manufacturing equipment users don’t always have the wherewithal to inventory sufficient spares of high-wearing tooling for assembly and stamping processes.

In some manufacturing applications, such as assembly line operations, processes change periodically. This can make it necessary, or at least desirable, to redesign or otherwise modify some equipment parts and thereby improve on equipment reliability or performance.

In many instances, the best solution to these problems is for the equipment owner to source spares or replacement parts from qualified tool and die makers or machine shops. In fact, those specialists may well have been involved in the design, finishing, or production of the original machine parts.

When sourcing MRO parts from a tool and die or machine shop, there are several qualifications and benefits that may usually deserve consideration.

Flexible Turnaround
Turnaround time is usually a primary concern, particularly when on-hand spare parts are few or non-existent. Assuming those parts are not readily available from the equipment OEM, sourcing from a tool or machine shop that has the flexibility to provide fast turnaround may be a deciding factor.

“One of the advantages of dealing with a tool and die or machine shop is they are usually flexible enough to meet our turnaround time requirement,” says Joe Fischer, shop supervisor atAdvanced Systems and Controls (ASC), Macomb, Michigan. ASC designs and builds custom machines and systems for testing and assembly operations for products such as automotive axles.

“Sometimes I don’t need a part for 4-6 weeks, and other times I might need it in a couple of days,” Fischer explains. “Either way, I look for a machine shop or tool maker that can usually handle the delivery requirement.”

Although price is a consideration, turnaround time can be worth much more than the cost of producing replacement parts quickly. If a part breaks and there is no spare available, that situation can become dire very quickly.

“Unplanned downtimes for any reason are often very serious, Fischer says. “If a worn or broken part causes a line to suddenly shut down and there are no spare parts, the manufacturer is going to want a replacement part ‘yesterday’ because they are losing valuable production time.”

Although ASC often carries some spares for the equipment it manufactures, the company also sources parts from outside tool and die shops, such as Belding Tool & Machine (BT&M). Although BT&M has plants in two locations (Belding, Michigan and Christiansburg, Virginia), proximity to a customer is sometimes less critical today. Companies now source parts across the U.S., since many suppliers are able to provide shipment of replacement parts virtually anywhere by express delivery.

Belding Tool & Machine makes it a policy to be very flexible with scheduling in order to provide rapid turnaround of emergency orders.

“We can’t take on every hot order, but we are often able to move our schedule around to fit our customers’ needs,” explains Jason Markham, BT&M president. “In fact, one of our customers recently emailed us about a piece of tooling they needed urgently, and we had it shipped to them the next day.”

Design Modifications
Another important consideration is the ability of the non-OEM supplier to provide design assistance. This is vital when the part needed has been damaged and no spare is available. In those cases, suppliers such as BT&M must have the resources available to reverse engineer the replacement part.

In other situations, the equipment owner may benefit substantially by having equipment components redesigned or otherwise modified. The opportunity may be to either achieve longer wear life or improve performance of equipment operation, particularly if the application has changed over time.

Jack Fuller, MRO manager at Ventra Automotive (Ionia, Michigan) says that making changes can also occur because of the way a part is mounted on some types of equipment. Ventra makes bumpers and grills for GM, Ford, and Chrysler, and has the capability to produce replacement parts using its own tooling, or goes outside to tool and machine shops.

“Sometimes we have a change in equipment or a change in how a part mounts on a machine,” Fuller explains. “In that case, we occasionally need to change the product a bit, and we need to have a tool maker such as BT&M help to redesign it.”

Fuller says an example of this is the copper V-blocks used to support tanks used in Ventra’s bumper and grill plating operations. The V-blocks have to be milled and cut to precise dimensions.

“There are times when you can have a vendor analyze how a part broke in production, due to some sort of application or design flaw,” adds ASC’s Fischer. “With their tooling experience, they may make suggestions that the part be modified using a different material or adding or subtracting different features in the tool in order to provide longer life or improved performance. Not many OEMs that I know of offer that kind of flexibility.”

Fischer adds that even though ASC designs and manufactures components, sometimes the company looks outside to tooling specialists, such as BT&M, for other ideas, even in original equipment design.

Relationships Count
Most equipment manufacturers or users agree that having a strong relationship with suppliers is more important than ever.

“Most industries are very competitive today, and I believe it is important for companies such as ours to partner with our customers,” says Fischer. “We, in turn, ask our suppliers, such as BT&M, to partner with us – on a 24/7 basis, if that’s what’s necessary.

“It is particularly advantageous if the supplier can handle all of the necessary fabrication processes in-house. That eliminates the need to go to another vendor to do one or more aspects of the required parts manufacturing processes, regardless of parts complexities. That capability gives them much greater control over every function from design through finishing, and also extends to improved cost controls and delivery times.”

Ed Sullivan is a technical writer based in Los Angeles.

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