Case Study: Diecaster Gets PM Advantage

Sept. 12, 2005
with wire-mesh belt machines

Ryobi Die Casting supplies aluminum components to automakers and automotive suppliers from its QS9000-certified facilities in Shelbyville, IN.

The manufacturer was challenged to find machines for deflashing large aluminum diecastings, such as transmission housings and casings, and related castings, in order to create a uniform finish — and to operate in compliance with its own stringent maintenance requirements. It’s a demanding task in tough operating conditions for the cleaning machines, and while the choice of equipment is critical, Ryobi’s intensive preventative-maintenance program has extended the service life of its systems.

“Maintenance is absolutely the key in making these machines run longer,” explains maintenance supervisor Dave Bentley. “We don’t have to get rid of them or quit using them; we just maintain them and keep them running.”

Several years ago, dissatisfied with its existing cleaning equipment, Ryobi accepted a proposal from Wheelabrator Group for a line of wire-mesh belt machines line. Wheelabrator’s Autoblast units are offered as four-, six-, and eight-wheel models, in widths up to 60 in. Electronic variable-speed conveyor controls maximize finish and production flexibility.

Standard features include easy-to-maintain blast wheels with TargetLok control cages and V-Lok blade features. Wheelabrator’s engineers and designers provide simple modifications and customizations for customer requirements.

Since the late 1980s, Ryobi has ordered 10 Wheelabrator wire-mesh belt machines, and the two newest have been installed recently at Shelbyville. The machines, all Autoblast, are customized 36 in-wide units, set up for use in individual work cells. The machines are robotically-loaded and unloaded, and handle one housing/casting every 14 to 20 seconds. Preventative maintenance was a must since the machines must operate on average two shifts per day, five days per week.

In accordance to Ryobi’s preventative-maintenance program, one line is taken down each week to perform any necessary repairs. “We have experienced significant reduction in downtime with our machines due to preventative maintenance,” says Bentley. “When we first started the program, our average downtime for our shot-blast equipment was 8-12%. Now, two years into the program, our average down time is 4%. It is hard to figure the cost of downtime as a production expense, but our general savings as a result of preventative maintenance is pretty tremendous.”

Wheelabrator and Ryobi engineers worked together to customize the machines, to meet the diecasters’ specific needs. For example, nylon elevator buckets make replacement and service simpler. Also, the blast wheels were also developed for easy replacement or maintenance.

“Nylon elevator buckets are very important to us because we don’t have overhead cranes,” says Rick Croslow, maintenance manager with Ryobi. “This takes a six-man job down to a two-man job. It took so much longer before because the work area is tight and a portable crane is difficult to get into the area.”

Another customization was the addition of a larger platform on top of the machine to provide better access around the elevator. “It had really become a safety issue for us,” says Chris Field, finish processing engineer. “It was difficult and dangerous to perform maintenance while hanging over a guard rail. We suggested a larger platform, and Wheelabrator has accommodated us on the new machines.”