In the Groove: Shaped From Solid Steel
The machines at New Hampshire Industries that cut and shape drive pulleys from a thin piece of solid steel in less than 30 seconds are easily the most intriguing and fascinating of all the automated processes.
“Those drive pulleys are probably the neatest process we have because they are split,” company President John Batten said while holding one of the thin discs, called a blank, in his office at NHI’s plant off River Road in Claremont. “The machines will spin in a tool and the tool will actually split (the disc) right in the center. … Once it splits there is another tool that comes and actually forms the pulley. So out of this one piece you’ll get a pulley with a groove cut into it for whatever belt size you need.”
Seeing is believing, but sometimes even that’s not enough.
“When I got hired they put me out on the floor for three weeks, and to see that piece of steel get split in half — I was at that machine all day and was absolutely amazed,” said NHI product engineer Alex Moskalenko.
On the production floor, employee Roy C. Borcuk prepares to place a round blank inside the machine.
He opens a small, windowed door on the machine and lays the blank inside on a post, then shuts the door.
The first tool moves in and splits the steel followed by a second tool that forms the pulley.
“What happens is those little tools have the reverse shape of the groove,” Batten explained.
“We had an MIT professor come through here one time and he stood here for 30 minutes. He comes back and says, ‘That is the coolest thing I have ever seen. I would have never guessed you could do that with steel.’ It is pretty neat.”
A machined hub will be welded into the pulley’s center to allow for a shaft with splines to lock in and turn the pulley. That is different from an idler pulley which has a bearing pressed into the center and is made by welding or riveting two pulley halves together.
“This was my first machine (that I operated), so I have seen it done, but yes, it is a pretty amazing process,” Batten said. “You look at that and say, ‘How can you do that with a piece of steel?’ ”