FEATURE ON GRINDING & HONING

Honing capability added to machining centres

Engis UK, offers customers a tooling solution which effectively replaces the expensive and skilled “black art” of honing, putting the process firmly into the range of repeatable and cost-effective machining centre tasks on standard vertical and horizontal CNC equipment.

The tooling’s design overcomes issues caused by lack of height within many machining centres, and removes the need for floating toolholders and adaptors (enabling the bore finishing tools to be held directly in the machining centre toolholders), while still providing the required high-accuracy geometry demanded of bore-finishing operations, e.g. roundness to within 1 µm and surface finish to 0.2 Ra.
Using Engis’ flexible tooling system, the first tool passes through the bore with a single in-and-out stroke, and its place is then taken by the pre-set, single-pass tool. The number of tools used in any given application will vary depending on the amount of stock to be removed, the surface finish, the geometry and the material being machined.
Each of the new Engis pre-set, single-pass bore-finishing tools is coated in a single layer of diamond, which is permanently plated on to the tool, creating faster cutting/stock removal rates and ensuring that tool sizes can be held for long periods without adjustment.
For further information www.engis.com

Vibratory bowls take over from hand finishing

Galvanometers for laser-beam steering and scanning in surgical, analytical and other applications include a precision-machined housing in which the stator moves. At the Poole factory of Westwind Air Bearings, which manufactures galvanometer components for its US parent group, Novanta, these coil housings are CNC-turned from mild-steel bar to within grinding tolerances.

Dimensional accuracy is down to 5 µm, while surface roughness of the bore and outside diameter are Ra 0.4 and 0.8 µm respectively. It is curious then that such precise components are subsequently rumbled in batches of up to 400 in a pair of vibratory bowls supplied by PDJ Vibro.
Nevertheless, by developing a viable production route that incorporates vibratory finishing, Westwind has been able to save a lot of time and money in comparison with manual finishing. In addition, the uniformity of finish is better using the automated procedure as each component is processed consistently rather than being subjected to the inconsistencies of hand deburring. In total there are 12 part numbers, two-thirds of which are required in relatively high volumes of 3000 per week.
John Bradley, senior manufacturing engineer, says: “Fine fettling of the housing by hand, together with washing cycles before and after finishing, took three people five hours, i.e. 15 operator-hours, to complete a batch of 100 housings.”
Today, it is normally team leader Martin Graham who processes the components in the PDJ Vibro vibratory bowls in a two-hour cycle, without the need to wash the parts at all. They go straight to plating after a quick air blast to remove any media resting in the bore. Overall there is a 7.5-fold saving in labour cost compared with hand processing, and a 60% reduction in finishing lead-time.
For further information www.vibratoryfinishing.co.uk

J&S Suprema grinder fits the bill at Bowmill

At its new Tewkesbury manufacturing plant dedicated to the production of Airbus landing gear kits, Bowmill Engineering has installed a Jones & Shipman Suprema Easy cylindrical grinder as part of its multi-million pound machine tool investment programme that includes eight new machining centres and high levels of automation throughout. The factory in Tewkesbury replicates a similar bespoke facility at Bowmill’s headquarters in Poole.

Nick Epps is the managing director of Bowmill and when it came to specifying the grinding machine, he admits a particular affinity with Jones & Shipman: “I’m a time-served toolmaker by trade and a good deal of my apprenticeship was undertaken using J&S manual machines. Here at Bowmill we operate three J&S machines in Poole, while a sister company – Taymar Precision Grinding – also operates a number of J&S machines.
“The Jones & Shipman Suprema Easy is a multi-purpose machine that is known as an ‘all-rounder’ being equally adept at processing high-volume production grinding work or fulfilling high-precision, small batch quantities and one-off work as encountered in environments such as ours,” he continues.
Bowmill has identified nine critical Class 1 kit components that require grinding tolerance finishes – retaining pins, uplock pins and spacers. Some are chrome-plated – a grinding challenge in itself – but all grinding programmes are stored in the memory of the machine’s Easy graphical software which offers a real advantage with its speed of set-up for dressing and grinding cycles utilising touchscreen technology.
Bowmill’s machine has a 650 mm grinding capacity between centres, although longer 1000 and 1500 mm capacities are available.
For further information www.jonesshipman.com

Faster surface finishes with stream technology

A new generation of stream-finishing machines built by OTEC Präzisionsfinish is now available in the UK from Fintek. The SF1-Automation with chain loader is typical of the range. The ability to load and unload without stopping ensures the best return on capital investment.

In stream finishing, components are clamped in a holder and lowered into a rotating container filled with grinding or polishing media. The finishing effect is generated by the media flowing around the parts, as well as independent rotation of the components. The process offers very short finishing times.
Smoothing, polishing, edge rounding, deburring and removing coating droplets are all tasks at which the OTEC SF1 is said to excel. A combination of these is usually performed in a single operation, producing surface finish values as low as Ra 0.01 µm.
The SF1-Automation chain loader has 64 positions which can change in diameter according to the workpiece or tool to be processed. Parts ranging from 3 to 32 mm in diameter can be finished in a single batch.
Cycle times depend on the complexity of geometry and standard of finish required, but typically range from 30 to 300 seconds. The SF1 is suitable for both dry and wet finishing.
OTEC stream finishing units are available in different drum sizes and with different media/compounds. Fintek is able to supply all supporting services, including installation, training and support.
For further information www.fintek.co.uk

Software and robots from Anca

Visitors to the stand of Anca at EMO (Hanover, Germany) this week will find out how the company’s latest software product launch, Management Suite, aids customers keen on adopting Industry 4.0 strategies (Hall 6, Stand K59). Also in action on the stand will be company’s first Dual Robot technology.

Anca’s Management Suite provides customers with the technology to monitor the performance of their machines no matter where they are in the world. The software also enables companies to run smart factories by providing live production information that enables staff to make data-based decisions about operational improvements.
CNC grinders from Anca now have the capacity to integrate several manufacturing operations into a single production line using the company’s first multi-robot production cell solution. Using a single robot, TXcell can automatically load both the grinding wheel packs and the workpiece. However, with the addition of a second robot in the TXcell, the solution can also complete secondary operations unmanned.
A further innovation in the EMO spotlight will be the new TX Linear, which will be on show for the first time in Europe. Among the stand-out features are Anca’s LinX linear motors on the X, Y and Z axes, an updated Anca AM5X CNC and servo drive system, and a new user-friendly front panel with touch-screen and ergonomic tilt adjustment to suit different operator heights.
For further information www.anca.com