About 6 years ago, Empire Comfort Systems, Inc., (Belleville, IL, U.S.) realized it had a problem. It had been using a 300-ton conventional press as a backup for its larger presses for about 10 years. But, over time, more and more jobs were run on this press, until it became overloaded.
“What we needed was another press to complement and back up this press,” says Sean Kennedy, production manager. “We were looking for something that was the same tonnage and bed size and would handle the same tooling and dies.” Among the pieces it produced on the press were inner and outer casings and heater and burner parts. The company manufactures space heaters, fireplace products, and outdoor products including grills.
The appliance manufacturer then explored all of its options, talking with equipment suppliers. It was then it discovered the NST straight-side tie rod frame press from Aida-America Corporation (Dayton, OH, U.S.). The press design features eccentric gearing and a high-energy drive for work being done higher in the press stroke. A rigid tie rod frame reduces deflection under load, and hydraulic overload protection is included.
In addition to such standard features, Aida proposed an additional feature—a lube-less roller guide technology. “While this technology is not new, it is normally only used on high-speed presses,” reports Denny Boerger, Aida’s product manager. “What we were proposing was, for the first time, to take precision zero clearance slide guiding system technology from high-speed presses and place it on a conventional press.”
There are two primary advantages to doing this. Most obviously, the lube-less aspect precluded having press lubricant drip or splash onto a metal strip going into the press. This can be a problem with pre-painted or brushed steels or aluminum. If lube drops are pressed into the part, they can join with or destroy the finish, resulting in scrap. This was not an option for Empire Comfort, which was producing brushed stainless parts for its grills.
The other main advantage is addressing lateral slide movement resulting from off-center loads. If a press is running multiple stage dies, not all stations will require the same load or work at the same position in the stroke. The slide tends to cock in the direction of the highest load and move laterally toward this load. With a pre-loaded roller guide, lateral movement is reduced or eliminated. “If the dies don’t move as much laterally, they aren’t going to wear out as rapidly, and there will be less maintenance,” points out Mr. Boerger.
“Aida offered us a good deal to be the first company to buy a press with this feature, and we agreed,” says Jim Klass, Empire Comfort’s lead concept product manager, who was involved in the press selection. “We especially liked the lube-less aspect, since presses get messy with lubricant. After about 3 1/2 years, the new press continues to work great.”
According to Mr. Boerger, many conventional press purchasers are not familiar with roller guide technology, unless they have worked with high-speed presses. “The challenge has been to overcome any anxiety by familiarizing people with the benefits,” he explains. “We’ve done that with test data on the technology’s resistance to lateral movement, and by establishing a track record, first at Empire Comfort and later at other companies. Today roller guide technology is included as a standard feature in all of our NST presses.”