Product category:
Pick-up spindle turning, multi-tasking, turning and machining centres
News Release from: Mike Page - editor's feature articles | Subject: Pick-up spindle VTLs
Edited by the Manufacturingtalk Editorial
Team on 17 August 2007
Pick-up spindle VTL - a true machining
centre?
Some while ago a production engineer said that the pick-up spindle vertical turning lathe can be the true machining centre, yet some countries don't make enough use of them, writes Mike Page.
Three years ago I visited a German 'Tier 1' automotive parts manufacturing shop that used mostly only two types of machine tool One was a very fast-acting vertical machining centre (VMC) with a variety of work-feeding systems
The other was the pick-up spindle vertical turning lathe (P/UVTL).
There were one or two grinding machines and a battery of automatic deburring and parts washing machines present too.
Some of the P/UVTLs were linked in two's and three's and some were linked up with a VMC.
Some were 'stand alone'.
Most of the parts flowing through the plant were transmission components and other castings and forgings, like stub axles, axles, water pump bodies and the like.
The VMCs were doing a variety of prismatic work that could not be picked up by the P/UVTLs.
Is it that a P/UVTL is too 'different' or 'off-beat' the reasons why some machine shops apparently do not use them? They have been around now for, what, 15 years or more, and the German-speaking countries seem to make the most use of them.
If you are not familiar with P/UVTLs, they were, in original concept, a lathe put on its 'end'.
Except that the 'moving headstock' is able also to traverse sideways and pick up any component that has a spigot or stub to grab with a chuck.
* Lower volumes automation - the concept brought 'immediate automation' to lower volume parts machining without the expense of traditionally adding on a multi-axes robotic gantry to load/unload parts to a normal horizontal production lathe's chuck.
The P/UVTL also avoided the lengthy downtimes associated with changing over the gantry robots.
Note that the 'ousting' of gantry robots is not necessarily the aim of P/UVTL style automation.
It is more a fact that the P/UVTL brings automation to low volume machining.
After all, all is needed is a conveyor (conventional or pocket, or pallet type) to bring the parts to the P/UVTL and remove the finished machined jobs.
You can have an accurate conveyor or a sensing system to position the jobs in the right place for the P/UVTL to pick them up.
Once in the P/UVTL a variety of machining tasks - depending on machine complexity - can be cycled.
EMAG in Germany, for example, began with turning and added on drilling, milling, grinding, hobbing and even laser welding over the years.
Initially, the standard P/UVTL consisted of a type of 'L' frame, the column holding the moving headstock and a traversing carriage with a tool turret doing the work.
Chips and swarf fell easily to the base of the machine for removal.
Adding 'live' powered tooling to the turret followed, with more turrets (usually two) added as an option - depending how complex the additional milling, drilling, tapping, slotting and other operations were to be.
A heavy-duty milling spindle could be added too.
In some case gear hobbing and shaping are possible on a P/UVTL.
As said before, grinding, hard turning and laser machining have been added, for example, machining/assembling clutch components.
It also goes without saying, that these P/UVTLs can be linked up into cells with, say machining centres or drill/tap centres - depending how the user wants to break up the machining cycles sequences to achieve a specific throughput.
If the potential user can say that really two P/UVTLs in harness would do all the work, then some builders will offer a twin-headstock machine.
One builder will also offer a P/UVTL that will pick up shaft components and centre them.
The forthcoming EMO 2007 exhibition in Germany (September 17-22) is the event to walk around and see what EMAG, Yamazaki Mazak, Hyundai-Kia and Index-Werke and others have to offer.
P/UVTLs from these companies can be found in Manufacturingtalk under the category 'CNC tuning centres, mill/turning centres, horizontal and vertical.
The P/UVTL can be a candidate for a true 'machining centre' in that it can carry out turning, milling, drilling, tapping, reaming, threading/tapping, hobbing - even limited broaching - and, maybe welding, depending upon the job.
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