Growth through automated grinding

The transition to being a member of a global group has seen Apex Cutting Tools expand its reach into the aerospace market, but with automotive tier one suppliers, as well as GM and Chrysler nearby, the automotive industry remains a core focus. The growth of the company located near Niagara Falls now sees it undertake the processing of over 1000 re-grinds a week for a single customer. With an output of more than 10,000 carbide and PCD tools a month, the company also manufactures hundreds of steel tool bodies with indexable inserts in the same timeframe.

Apex Cutting Tools produces more than 2000 new PCD and solid carbide tools each month, with more than 8000 tools on a repeat cycle of re-grind, re-coat and re-supply to clients. This total output has more than doubled in the past 10 years. Notably, each and every tool is a special, which makes production at Apex Cutting Tools far removed from the volume production market. The company operates two shifts, and if machines can be loaded with a batch of tools for overnight production at the end of the second shift, they will be. This strategy sees machines like the Vollmer Vgrind 160 running up to 24 hours a day.
CNC Grinding Department supervisor at Apex Cutting Tools, Stephan Rodrigue, says: “The breakdown of our production is relatively equal between PCD and indexable tools, with solid carbide being the majority of production. Our volumes are generally in the range of 5 to 50 tools, with some runs occasionally reaching a few hundred. We have one customer that comes in on a Friday with a 1000 tools that have to be re-ground by the following Monday.”
The company has a series of manually loaded CNC tool grinders, which are now reaching the end of their service life, something likely to be expedited by poor machine support and the arrival of automated machines like the Vollmer Vgrind 160.
Referring to the acquisition of the Vollmer Vgrind 160 just over two years ago, Rodrigue says: “The company invested heavily in DMG Mori and Mazak machine tools for producing tool bodies, Zoller Genius tool measuring machines and a range of CNC tool and cutter grinders. We were invited to look at the Vollmer Vgrind 160 machine but, as it was going to be our first Vollmer, we were somewhat apprehensive. Our opinion changed as soon as we looked closer. Now it’s here we’re thoroughly impressed and already looking at a Vollmer erosion machine.”

One of the key features that drew Apex Cutting Tools to the Vollmer Vgrind 160 was the CNC control platform, as Rodrigue explains: “The Vollmer has the Numroto Plus CNC software platform, which is a different control system to our older tool grinding machines. Numroto is now on most of our new machine acquisitions and the Numroto Plus platform is a must for us going forward. This is because it allows any program to be swapped between any of our new machines, regardless of brand.”
The thousands of solid carbide tools are produced or re-ground on four automated CNC grinding machines and three ageing manually loaded machines.
“As we produce tools with shank diameters from 3 up to 20 mm in 1 mm increments on the Vollmer, they were kind enough to give us the drawings to produce our own collection of auto-load pallets in our own machine shop,” says Rodrigue. “As standard, the HP160 pallet magazine can hold 272 tools with 3 mm shanks, while for larger tools with 20 mm shanks, we can hold 54 tools. We also have a special collet in the spindle for doing tool shanks up to 25 mm and the machine has a steady rest to support the production of drills over 200 mm long. The HP160 with its two-pallet system works fantastically well, and the tool capacity gives us long periods of automated production.”
Of critical importance to the prolonged periods of unmanned running is the auto-change six-wheel pack that is stored at the rear of the machine. Automatically, the wheels are measured in-cycle with a probe, dressed and/or changed depending upon the geometry of each tool. So, regardless of whether the HP160 is loaded with carbide blanks or tools for re-grinding, the Vgrind will undertake complete fluting, geometry generation or re-grinding to the exact program specifications.
Comparing tool production cycle times to alternate machines in operation at Apex Cutting Tools, Rodrigue says: “This is a tough question as all our machines have different capacities and power levels, but in most cases the Vollmer gives us cycle time gains over our other machines. This is largely due to the vertically aligned spindle configuration on the Vgrind. For example, we will rough grind the flutes on the lower spindle and then do the finishing cycle on the top spindle, which instantly removes the constant wheel changes that are common on our other machines.
“The finishing wheel will undertake micron precision grinding with outstanding surface finishes whereas the rough grinding can really rip the material off,” he continues. “We are doing a 24 mm diameter tool at present with a 12 mm core diameter and the Vgrind will grind the flutes in a single pass. Compared with most of our other machines, this stock removal is well above their rates. The Vgrind is at least 30% faster at roughing than some of our older machines. This is impressive considering the machine has belt driven spindles as opposed to the direct drive spindles on newer Vollmer machines.”

Despite the Vollmer Vgrind 160 being significantly faster than alternate machines, Rodrigue says it is difficult to draw parallels between the various grinding centres at Apex Cutting Tools.
“We have manually loaded grinding machines, machines dedicated to small tools and others dedicated to hob grinding, so like-for-like comparisons are difficult. What we have noted is the kinematic advantages of the vertically aligned twin spindles that pivot around the C axis. Firstly, having two wheels in the work envelope reduces wheel changes to improve processing speed. Secondly, the extremely robust grinding wheel column maximises rigidity and vibration damping. It is this rigidity that contributes to massively reducing flute roughing times. The closest comparative machine would be a very high-end machine that cost hundreds of thousands of dollars more than the Vgrind.
“An extra rail at the top of the C axis gives the axis support from the top and bottom and the whole thing can swing around and grind from two positions,” he adds. “The solidity of that whole system and the spindles Vollmer uses, that’s just the biggest factor. There is no comparing that. Some of our machines have a suspended spindle, so you lose precision, surface finish and the rigidity depends fully on the spindle. Here, you have a massive structure that comes in and really takes out the material.”
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DMG Mori open house

At DMG Mori’s traditional open house to be held in Pfronten, Germany from 11 to 15 February 2020, areas of focus will include end-to-end connectivity as the standard for all machines, updating existing versions of the CELOS machine interface, the new customer portal ‘my DMG Mori’, and the co-operation with US software provider TULIP as an entry into digitalisation.

Among more than 40 machines on show there will be three world premieres: the DMC 65 H monoBLOCK universal, horizontal-spindle machining centre, the modular PH Cell automated pallet handling system and the LaserTec 400 Shape for laser texturing.
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Laser provides enhanced cuts

The Ventis-3015AJ from Amada is the first fibre laser cutting machine to feature the company’s LBC (Locus Beam Control) technology, which improves both processing quality and productivity in stainless steel and aluminium. The machine also features a newly developed, high-brightness fibre-laser oscillator with single diode module (4 kW).

On conventional fibre laser cutting machines, energy density reduces as material thickness increases, leading to a lack of efficiency and the need for de-focusing the beam. Conversely, the use of LBC Technology, which is said to be a world first for the laser-cutting market, offers flexible beam pattern control matched to each application, while retaining high-efficiency cutting and high energy density. De-focusing is therefore no longer required. In short, LBC Technology can freely manipulate the laser beam to create an infinite number of locus patterns that are advantageous to cutting performance.
For manufacturers of conventional fibre-laser systems, the only way to negate the loss of energy density is to increase the power output of the laser oscillator, but this comes at a cost, both in terms of purchase price and greater electricity consumption. In contrast, the new Ventis, with its specially developed, 4 kW single diode module oscillator and LBC technology can reduce electricity bills by 30%, says Amada.
LBC technology can operate in three primary modes: productivity mode, quality mode and kerf-control mode. The most notable gains from integrated LBC technology are available on stainless steel up to 20 mm thick, and aluminium up to 18 mm. Ventis can also be used for processing many other materials, including mild steel (up to 25 mm), brass
(10 mm) and copper (8 mm).
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Quaser acquires Winbro Group

Winbro Group Technologies Ltd has been acquired by Taiwan headquartered Quaser Machine Tools (QMT).

QMT, a publicly traded company, is a manufacturer of multi-axis machine-tool technology with locations in Taiwan, USA and Europe. The Winbro Group provides manufacturing solutions to the aerospace and industrial gas turbine industries, based upon its core laser and high-speed EDM cooling hole machining technologies, as well as viper grinding and ECM machining processes. Winbro provides turnkey machining systems, services and manufactured components from its UK and USA sites.
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Machining and AM in a single platform

A new five-axis machining centre with integrated laser-deposition welding capability for accurate, reliable, cost-effective, complete production of complex components in one hit has been introduced by DMG Mori. The LaserTec 125 3D hybrid is intended for the manufacture, maintenance and repair of workpieces up to 1250 mm in diameter by 745 mm high, and weighing up to 2000 kg.

Based on DMG Mori’s rigid MonoBlock platform, the LaserTec 125 3D hybrid offers automatic changeover between laser-deposition welding and simultaneous five-axis milling in a single set-up, reducing processing times by up to 80%. Such savings are helped by eliminating the need for heat treatment as a separate process step due to the machine’s ability to deposit material with a hardness of up to 63 HRc.
The alternate use of laser-deposition welding and simultaneous five-axis milling is beneficial for improving production processes or enabling new component geometries, an example being the manufacture of closed impellers. Another strength of these hybrid machines is the production and repair of hot and cold forming, and forging dies.
DMG Mori’s LaserTec 125 3D hybrid can also produce lightweight structures that reduce the weight of parts by up to 90%. A selling point of laser-deposition welding is the possibility it offers to change between two materials quickly under CNC. So, for instance, hard surfacing to reduce wear can be carried out in one area and corrosion-resistant welding for environmental protection may be performed in another. Alternatively, the cooling characteristics of a part can be significantly increased. As an illustration, a die-casting mould can be produced by starting with a bronze core that dissipates heat effectively, and welding on to it an outer skin of tool steel.
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