Straps: The Underestimated Link in Designing OEM Products

Straps can literally make or break a product, but up-front attention pays off with reduced manufacturing costs and timely production schedules.

How'd you like to be considered the Rodney Dangerfield of assembly parts? Can't get no respect? Ponder the plight of the seemingly simple, but deceptively important, strap. The roll out of many a new product has come to a screeching halt during initial prototyping when internal or external straps get relegated to a last-minute manufacturing supply issue. When shortcomings surface, costs rise and deadlines get pushed back as engineers scramble for a replacement.

However, proactive design engineers are learning to treat straps with a lot more respect. By carefully considering the many aspects of straps and consulting with strap vendors early in the design process, problems can easily be avoided. Oftentimes, commercial off the shelf (COTS) strap products can fill the need¾as opposed to requiring a custom designed solution-thus saving significant amounts of money while speeding time to market.

"If I hadn't found a strap provider who could bail our project out, we probably would have had to pay somebody on the outside to redesign a strap to replace the defective one originally called out," says Larry Switzer, Senior Manufacturing Engineer at FLIR Corp. "Luckily, we teamed up with a strap vendor who helped us out. It saved us an incredible amount of time. It was one of the 'kudos' of this program."

Foresight in Design Avoids Costly Consequences

Straps are utilized in an extremely broad range of OEM products within diverse industries such as: durable medical goods, computers, automotive, aerospace, consumer electronics, boating, communications, arms, material handling, robotics, sporting goods, appliances, etc.

Despite their ubiquity, many design engineers fail to consider the importance of straps¾to secure parts and assemblies, allow for reuse, attach product to consumer, etc.¾until after much of the product is designed. Yet, the consequences of ignoring items of importance such as attachment points, slit widths, and materials for straps can literally make or break a product.

"Nintendo to Replace 3.2M Wii Straps," headlined an Associated Press story that ran on December 15, 2006. The story continued: "Nintendo said Friday it will replace 3.2 million straps for its popular Wii computer game controllers after receiving a rash of reports that the device flew out of the hands of players....Nintendo will allow customers to exchange the old straps for a \[thicker\] beefed up strap...The worldwide exchange is expected to cost the company several million dollars."

Whether the damage occurs externally or internally to the product, or to the project budget in the form of delayed production schedules and additional NRE costs, the corporate "bottom line" is always threatened.

Design Advice Can Save the Day

In ideal cases, product designers turn to strap specialists to provide input early in the design phase, with much success.

"We make an $8,000 infrared camera system for see-in-the dark applications such as military and law-enforcement surveillance activities, but the outside designer called out a wet suit, neoprene type strap that turned out to be unusable-it had insufficient strength," explains FLIR's Larry Switzer. Based in Wilsonville, Oregon, FLIR Systems is a world leader in the design, manufacturing, and marketing of thermal imaging and stabilized camera systems for a wide variety of thermography and imaging applications.

"The camera was created for use in harsh environments where it would get thrown and banged around a lot, but the original strap could not hold up, and it only came in one wrist size," continues Switzer. "So now my challenge was I had a camera that was fully designed, with fixed attachment points, fixed threads, and fixed distances. But I had to come up with a custom strap that was functional, easy to use, and durable.

"Our volumes are fairly low, but most suppliers wanted 10,000 piece minimums or they wouldn't talk to you. I finally did a Google search and found Toleeto, and they came up with a design and a price that was phenomenal. The materials were very durable, and the size was correct. They had the right attachment that would fit my attaching screws perfectly. Additionally, their strap was expandable so it could accommodate a number of wrist sizes."

Based in San Ysidro, California, Toleeto Fasteners International has been in operation since 1985, and is a major supplier of millions of straps to OEMs throughout the world. A one-stop, vertically integrated strap designer and manufacturer, Toleeto's production equipment includes: a 10-ton clicker press to die-cut neoprene, leather, and hook and loop material; ultra-sonic welding machines to fuse differing materials; over a dozen industrial sewing machines to construct customized strap variations; and 3 pad printers capable of printing high definition logos on a variety of materials.

"We've often seen major products, by world-leading OEMs, being held up at the last minute because of a 25-cent strap that is an odd size," observes Dave Deavenport, president of Toleeto. "The manufacturing engineers know they need something, but they are not always aware of what's out there. That's where a strap manufacturer with a large array of product offerings can help, but the most time and money is saved when the design engineers come to us early in the process."

Important Considerations to Improve Functionality, Reduce Cost, and Speed Delivery

By utilizing a strap manufacturer as a design partner and service provider, rather than just a parts supplier, many production problems can be completely eliminated. Valuable advice begins with the actual product dimensions.

"Oftentimes, constraints in strap options develop because of the slits and attachments already built into the molding of plastic parts or in the punching of metal, and so the OEM is left with ordering a custom product," notes Deavenport. "However, a strap vendor can provide advance recommendations of common slit widths and depths that can accommodate COTS straps. Not only does this dramatically drop the price of the part, but prototyping quantities can be easily obtained, and quite readily at that. Just as important, the OEM isn't locked into one supplier."

Common strap width sizes include 3/4" or 1", as opposed to 11/16", for example. Additionally, the chosen material makes a difference when considering sizes.

"Calling out a Velcro strap width of, say 430 mils, is not realistic," says Deavenport. "We are dealing with textiles here, not metal. The normal tolerance in these materials from the manufacturer can be ±1/16" or more. The material will move and expand, so there is no need to get too exact. Allowing some leeway in the slits and attachments provides a wider range of options and substitutions."

Even among material types, many choices exist. Expanding on traditional Velcro, there's stretchable hooks, stretchable loops, and various sizes and strengths. Other materials include straps of nylon, polypropylene webbing, or combinations such as webbing with hook and loop at each end, or webbing sewn to the back of the loop.

Variations of securing the straps include grommets, buckles, D-rings, snap-hooks or simple snaps. Gradients of strength exist from quick release straps to very aggressive hook-and-loops that require pliers to pull apart.

"Even electrical conductivity can represent an important issue for some OEMs," Deavenport points out. "Many engineers don't realize that some straps come with ULÒ ratings, and they can even be made to conduct electricity."

Other factors to weigh up-front include: waterproofing, UV protection, elasticity, reflectivity, fire resistance and thermal conductivity.

A New Attitude

While straps may never garner star billing in any project, the expertise of strap manufacturers in helping OEMs develop new products on time and on budget has allowed straps to "get a little respect."

"Instead of designing the strap yourself, it's better to team up with someone who is already an expert, because you're just going to reinvent the wheel if you try and do it yourself," advises Switzer. "A company who specializes in straps, like Toleeto, has the knowledge, the hardware, and the materials to save a manufacturer a lot of time and money."

For more information, contact Toleeto Fasteners International; 1658 Precision Park Lane; San Ysidro, CA 92173; (619) 662-1355; fax (619) 662-1486, or www.cord-lox.com .