November 2007 Edition
FROM THE SHOP FLOOR
The Hybrid Machine Future Fast Approaches
Demonstrations of hybrid machines at the EMO technology show convince Dave that the future is now
Dave Sterling, Application Engineer Ansco Machine Co.
There are two kinds of machine tools: mills that rotate a tool against a work-piece, and lathes that spin a work-piece against a tool. These two standards stayed the same over the years, each evolving into today's machine tools. Eventually computers and drive motors replaced dials and handles and CNC took over, but you know all of this. The next chapter in machine tools is being written right now, as the line between lathes and mills blurs, creating a new class of hybrid machines.
It's a simple concept. If a piece is being held, why move it to another machine to add a new feature? In the past, there was little choice but to move a piece to a machine with the specific capability to drill a hole, turn a boss, or mill a flat. But, technology and ingenuity make it possible to minimize handling, and in some cases, finish a piece in one machine, despite the design features.
A Novel Idea Becomes Reality
The idea of completing all operations with one machine was more of a novelty than a reality. Technology available wasn't suitable for handling anything but the most basic features. Lathes could be equipped with drills or mills, but they had only X and Z axes, and only could make certain features. These tools also suffered from being bulky and underpowered. A job with a large number of tools was a problem.
The all-in-one hybrid machines, demonstrated at EMO, have come into their own
A group from our shop attended the EMO tool show in Germany in September, and from the evidence it looks like the technology has come of age. Nearly every machine tool company displayed hybrid machine tools. Some resemble lathes, some look more like mills, but once we opened the machine doors, we saw a whole new breed.
The lathe-based hybrids have the typical lathe headstock, and slanted bed. Some have a conventional lathe turret – or turrets – but a closer look reveals most have a perpendicular slide, providing the machine with a Y-axis. This allows for off-center cross-holes, or machining off-center squares on any face of a work-piece.
Other machines have a fully-articulating B-axis riding on the cross slide, giving the machines not only a full fifth axis, but also the capability to change tools with an automatic tool changer. These machines are not only high tech, they are high powered, achieving the same depths of cut as traditional machines.
Hybrid machines, based on milling frames, appeared to be typical machining centers until we saw them move.
At one booth, a German builder showcased a machine with 3.4m turning tables. This machine could both turn as a vertical boring mill, and also perform full five-axis machining, including all the functionality of a horizontal machining center and a vertical machining center.
Fast Mover
Added to these capabilities was a pallet changer for setups outside of the machine. In short, there wasn't anything that this machine couldn't do. On top of all of that, it was fast!
All of these machines look great at a trade show booth, but what can they do once on the shop floor? This is where problems occur.
The first problem with these machines is their complexity and multiple axes. Conventional programming and setup methods may not keep up with them.
The other challenge of hybrid machines is with personnel. While many machinists have run both lathes and mills, most choose a specialty and perfect their craft in that machine area. If the machine is both a lathe and a mill who can run it? For even with a cross-trained machinist, the intimidation factor must be considered. The first time the Start button is pushed can be nerve-wracking.
At my shop we are just scratching the surface of hybrid machines. The technology is maturing. Five years ago hybrids were a novelty, today they promise a competitive edge, tomorrow they will be a necessity.
Dave is responsible for programming, tool selection, and fixture design for Ansco Machine's 20 CNC machines in Peninsula, OH. He's been working in a machine shop since age 12, starting by drilling holes on a turret lathe and making simple parts on a Bridgeport.
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