Optimized machining: FROM PRACTICE TO PRACTICE - SLOTWORX® "L"

Optimizing of machining a component from Cu-HCP (CW021A) (best selected copper min.99.5% purity), with a tensile strength of approx. 300 N/mm² only, but a breaking elongation of over 40%.The metal removal volume for this component was 55%, for a quantity of 48 pieces. Previously,this component with unmachined dimensions of 258 mm long, 123 mm wide and 211 mm high was machined with a Square Shoulder Face- and Slot Milling Cutter with inserts having 0.8 mm corner radius. But with this tool, maximum cutting depth of ap = 3 mm could be realized, otherwise the component started vibrating under the enormous cutting pressure. This was a very negative influence to the roughing operation. Although the customer had rated the tool life of the inserts as satisfying, this was not our valuation at all. The no. of components was increasing constantly , and regarding production capacity, a decision had to be made.A solution for better machining possibilities was found by our applications engineers immediately. The new milling cutter body from our Slotworx®-L range 5 52 368 (52 mm diam., r = 1) should be suitable outstandingly for this application, and it was selected together with our new indexable inserts 05 68 896, specially developed for cutting corrosion- acid- and heat-resistant materials, having sharp, but slightly radiused cutting edges and our special coating with lubrication additives. This special coating avoids chip-built-up of this best selected copper and cares together with a sufficient coolant supply for optimum chip removal.

machine: OKUMA
material: Cu-HCP
machine control: manual

This component has been produced countourparallel in z-constant cycle in climb milling as well as conventional milling. Regarding machining time, the feed rate and thus the chip volume has been increased by 4 times. This results in a reduction of the previous machining time from approx. 30 minutes to slightly more than 6 minutes. Through the special design of the minor cutting edge of these Slotworx®-L inserts we could achieve very good surface smoothness and minor waviness in the vertical parts of the component, even in cutting depth ap of 5 mm.

EXAMPLE FROM PRACTICE:
component: slot
material: Cu-HCP, CW021A
arbor: 50 22 710
(22 mm diam., SK 50)
cutter body: 5 52 368
(52 mm diam., r = 1)
insert: 05 48 896, M40
coating: PVST
overhang: 103 mm
vc (speed): 571 m/min
vf (feed rate): 4.000 mm/min
S (revolutions): 3.500 1/min
fz (feed per tooth): 0,229 mm
ap (depth of cut): 5 mm
ae (width of cut): 32 mm
chip volume 640 cm3/min = 39 cu. in./min
machining time 06:07 min

RESULT:
Machining time of this component has been reduced from 5 to 1.5 hours. This results – for 48 components and a calculated machine hour rate of 50€/hour – in savings of approx. more than 8000 €.Plus an increased machine availablility of 168 hours, which represents working hours of a complete month anyhow. This time saving can be used for other projects.

Further informationen:

Pokolm
Frästechnik GmbH & Co.KG
Frau Tatjana Peters
Adam-Opel-Str. 5
D-33428 Harsewinkel
Telefon: +49 5247 9361-0
Telefax: +49 5247 9361-97
E-Mail:tatjana.peters@pokolm.de
www.pokolm.de

The company Pokolm Frästechnik GmbH & Co.KG has its market place since 14 years and belongs to the leading manufacturers of special tooling for mould- and die-making worldwide. The company’s floor space is more than 2500 m² (approx. 25000 sq.ft.) and it has approx. 64 employees. All operation cycles –turning, milling and grinding- are taking place on ultra-modern machinery in air-conditioned production facilities for best possible precision.

Pokolm is dealing worldwide. Domestic sales is realized by well educated applications engineers, having extended knowledge in milling, machining- and control-systems as well as CAD/CAM programming. Pokolm are marketing their products in 39 countries via sales representatives, beginning in Eastern-Europe, direction Western-Asia up to China and Japan, down to Australia. And in the western hemisphere starting in the European Community, Great Britain, USA, Canada and South America. Substantial customers all over the world are supplied with Pokolm-premium-products.

This release was published on openPR.