Product category:
Special purpose and multi-function tooling, broaching, etc.
News Release from: Horn Cutting Tools | Subject: Broaching tools for CNC lathes
Edited by the Manufacturingtalk Editorial
Team on 22 February 2006
CNC lathes also broach key-way slots
in-process
The integration of broaching tooling in a CNC lathes by a contract manufacturer has reduced lead times, improved quality and increased design flexibility on a variety of components.
Adoption of the Horn 110 and 117 broaching system by Hailsham, UK, contract manufacturer Metaltech has reduced lead times, improved quality and increased design flexibility on a variety of components The Horn tooling allows key-way slot generation to be integrated with other machining operations on CNC lathe, rather than as a separate operation on a specialised manually operated slotting machine
This article was originally published on Manufacturingtalk on 27 Apr 2004 at 8.00am (UK)
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Broaching system for use on turret and platen-type lathes is believed to be the first proprietary system of its type and avoids having to broach keyways and slots on a second operation machine.
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This allows components to be finish machined via an all-CNC route.
Ken Elphick, managing director of Metaltech comments: "Before the Horn tooling became available the only alternative (to slotting) was to commission specialised broaches.
However the smallish batch quantities (20-50 off) required, together with regular component design changes made it difficult to justify investment in the necessary tooling.
Further reading
Dedicated tooling benefits sliding head users
Users of sliding head CNC lathes can benefit from using dedicated internal grooving and boring tool holders and adaptors as well as a side turning and part-off system and polygon mill-turning tools.
Milling inserts get deeper into the groove
Standard three tooth milling cutters include a derivative with a reduced diameter boss, allowing interpolative milling of deeper grooves than hitherto.
Insert manufacturer expands machining capacity
Tooling inserts maker has installed a second CNC insert grinding machine is already operational, to be followed by a third in April 2003, while a new laser engraving machine is also on order.
We would, in any case, still have needed a second operation.
Moreover set-up and operation of the slotting machine is a specialised, skilled process and we only have two people who are proficient in its use; they have other things to do and this inevitably extended delivery lead times." Metaltech celebrates the thirtieth anniversary of its foundation during 2006.
The company bought its first CNC machine in 1979 and has been a regular investor in CNC equipment ever since.
It produces components and sub-assemblies for a variety of industry groups, acting as a first tier supplier to a number of pump manufacturers in the UK and overseas.
The initial focus of the company's broaching ambitions were a range of flywheels machined from EN8 steel.
Overall diameter of the components ranges from 30mm to 100mm; the through key-way slot width varies between 6mm and 10mm and tolerance is +/-0.024mm.
Richard Page, technical supervisor at Metaltech, comments: "The material is quite tough which makes it a fairly difficult job that nevertheless needs doing with precision.
When the job was done on the slotter we were looking at around 8 min/ slot but the operator also had to maintain the HSS cutting bit to ensure that it produced slots to the correct width.
It was not a popular task." Metaltech is a long standing user of Horn grooving tooling so when the broaching system became available the company was among the first to know.
"Mark Turnidge (southern area manager for Horn UK) made us aware of the system and got some standard tooling sent over from Germany for initial trials." Page recalls: "Initially we were a bit sceptical but the system quickly showed itself to be highly effective." Following on from the trials, Metaltech ordered tooling derived from both the Horn SH117 (screw located insert) and Horn SB105 (Super Mini) broaching programs.
These are custom ground to provide the specified slot width.
Page reports that integrating the broaching cycle with the existing machining cycle on modern C-axis equipped machines posed no problems.
"Once we had worked out the trigonometry we were able to use a canned cycle, allowing us to establish the routine by specifying the X point and the depth of cut.
All of our machines have a tool setting probe so initial set-up of the tool is very straightforward.
If we need to replace an insert the dimensional consistency of the Horn inserts and the location repeatability of the holders makes it very quick." In practice, the system has proved to be much faster than manual slotting, at around one minute per slot, and also much more flexible than a conventional broaching or slotting routine.
For instance a temporary need for a slightly wider slot for which the tooling is not to hand can be accommodated through C-axis indexing and 'overlap' broaching.
As a result the Horn system has become the method of choice at Metaltech for generation of key-ways and slots in small to medium volume applications.
Thus far, as well as the flywheels the tooling has been applied to produce slots on a range of aluminium pulleys and hand wheels; other applications are under consideration on an as-needed basis.
Elphick concluded: "The Horn broach tooling has conferred significant advantages in terms of flexibility, productivity, feature accuracy and response to customers orders.
It gives us a competitive edge on new business and has definitely provided a worthwhile addition to our range of capabilities.".
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