That's the reason Great Trango Holdings of Boulder, Colo., uses orbital riveting to assemble its new Trango Cinch, a device for recreational climbing, including belaying and rappelling, outdoors or on indoor climbing walls.
The Cinch has three main parts, a black nylon handle, 7075-aluminum base, and 400 Series investmentcast, stainless-steel lever. Because falls can generate extremely high loads, holding the parts together in an unfailing, high-strength assembly is essential.
Trango engineers turned to experts at the Orbitform Group application laboratory in Jackson, Mich., to determine the best way to fasten the parts. They recommended orbital riveting the nylon handle to the base with a 7075 pin, locking the hardware in place with a conical peen. The cast lever attaches to the base with a 0.625-in.-diameter tube, rolled over a washer at each end to form an eyelet peen.
An Orbitform B-500 orbital-riveting machine sets both forms. The pneumatic riveter generates a maximum downward force of 4,400 lb at 100 psi, in adjustable strokes of 0.06 to 2.50 in. in 0.001-in. increments. It is powered by a 1-hp, 1,140-rpm motor. The unit handles short and long cycles, hard materials, and includes light-touch palm buttons for operator safety.
"Orbital riveting makes a very secure joint," explains-Seth Murray, a Trango design engineer. "The orbital process displaces a large amount of material without cracking, compared to other riveting methods we have tried."
The Cinch is designed with simplicity, dependability, and aesthetics in mind. It fits easily in the palm of a hand, weighs less than 6 oz, accepts rope diameters from 9.4 to 11 mm, and costs less than competing models.