http://www.engineeringnews.co.za
  SEARCH
Login
R/€ = 14.63Change: -0.07
R/$ = 10.59Change: -0.04
Au 1285.31 $/ozChange: 1.94
Pt 1401.00 $/ozChange: -2.00
 
 
Note: Search is limited to the most recent 250 articles. Set date range to access earlier articles.
Where? With... When?








Start
 
End
 
 
And must exclude these words...
Close Main Search
Close Main Login
My Profile News Alerts Newsletters Logout Close Main Profile
 
Nelson Mandela 1918 - 2013   Agriculture   Automotive   Chemicals   Competition Policy   Construction   Defence   Economy   Electricity   Energy   Environment   ICT   Metals   Mining   Science & Technology   Services   Trade   Transport & Logistics   Water  
What's On Press Office Suppliers Directory Research Jobs Announcements Contact Us
 
 
 
RSS Feed
Article   Comments   Other News   Research   Magazine  
 
 
Oct 19, 2012

A strategic overview of the production turning industry in SA

Back
DURBAN|South Africa|Electronics|Metal Removal Rate|Product Manufacturer
durban|south-africa|electronics|metal-removal-rate|product-manufacturer
© Reuse this

A vast number of industries, including the automotive, appliance, electronics, bathroom fittings and other industries, and products make use of turned components, says machine tools manufacturer FAS Machine Tools CEO Peter Frow.

In a research paper written by Frow, he points out that some of these components are made in-house by the product manufacturer, while others are subcontracted to specialist repetition turning ‘job shops.’ The component type and size vary enormously, as do batch sizes – anything from ten to hundreds of thousands.

“Where batch sizes increase above 100 and particularly above 1 000, the components will typically be made on one or other type of production lathe,” he states.

A production lathe is any lathe where the tool movements are achieved by some automatic means. Thus, once set, they can produce components without any direct operator action, except for loading the raw material.

“In the production turning stakes, it is important to select the best machine for the job.

“The best machine is the one that yields the lowest cost for a particular component and a particular batch size,” says Frow.

Generally speaking, the production turning industry uses two distinct types of production lathes – Cam automatic lathes and computer-numerically controlled (CNC) lathes.

The paper highlights that the design of the cam automatic lathe was pioneered over a hundred years ago and it uses cams for achieving tool movements. The lathes are characterised by fast cycle times and long set-up times.

Further, the paper states that CNC lathes were developed in the seventies, initially as hard-wired numerically controlled machines. They soon incorporated microprocessors, hence the term CNC. These lathes have relatively long cycle times, compared with cam-operated lathes, especially for smaller components, but are far more user-friendly and have relatively short set-up times.

“Within these two broad categories, production lathes can be further broken down into various subtypes (see Figure 1).

“The diagram illustrates that there is usually something of a trade-off between cycle time and set-up time.

“Cycle time is a function of the metal removal rate (MRR) of the different tools, the number of tools that can be made to work simultaneously on the work piece, and the time taken for nonproductive or idle operations, such as the feeding of material and indexing of tools.

“Thus, to optimise the cycle time, one must maximise the MRR, maximise the number of tools working simultaneously and minimise the duration of idle operations,” says Frow.

He points out that the cam-operated multi-spindle lathe (Type A, Figure 1) works on six components in various stages of completion at any one time. Thus, it has as many as 12 tools cutting simultaneously.

“Amazingly, this type of machine was developed in the late nineteenth century and still produces the quickest cycle times of any production lathe.

“However, South Africa has less than 150 of this type of machine in regular operation.

“The greatest number (estimated at 2 500+) of cam automatics in the country, are of the single spindle type (Types B, C, & D),” he says.

Frow notes that these machines can typically have four tools working simultaneously. They make extensive use of the ‘plunge forming’ technique, where tools having a particular shape are advanced into the work piece along an axis perpendicular to the spindle axis.

“By contrast, CNC lathes use single point tools and generate the required shapes with a digitally programmed tool path. Form tools can generally be applied at the same time that end working is taking place. This technique is known as ‘overlapping’.

“In order to select the best machine for a particular application, one should plot the cost-effectiveness curve for each machine being considered. Figure 2 would be a typical set of curves for a component of less than 40 mm in diameter made from bar stock.

“Other things being equal, the batch size represented by X would be the point at which it would be more cost effective to make the component on a cam automatic than a CNC lathe. Batch size Y would be the point at which a multi-spindle would become the better choice,” says Frow.

He points out, however, that other things are not equal: In particular, there is a dwindling pool of tool setters with the skills necessary to set cam automatic lathes. Each job requires a set of job-specific cams. The number of persons capable of designing optimum cams has also shrunk.

“There is thus a tendency to run jobs on CNC lathes despite their longer cycle times where the cost effectiveness curves would suggest otherwise.

“The great majority of CNC lathes in the country are of types J and K, although there are a fair number of type H lathes.

“Viewed at a macro level, the net effect of this is a tendency to drive component prices upward, making South Africa less competitive in a global market,” says Frow.

He notes that imported type E CNC lathes have cycle times comparable with cam automatics, but unfortunately are priced such that one can purchase about three type J machines for the same figure.

Further, he says that, despite fierce competition from the East, South Africa has CNC lathe manufacturers. “Efamatic in Gauteng produces a range of type J machines, while FAS Machine Tools in Durban manufactures a type E multi-slide machine with cycle times that more than match those of equivalent cam automatics.”

Edited by: Chanel de Bruyn
© Reuse this Comment Guidelines
 
 
 
 
 
 
 
 
Other Machine Tools News
NEW BEGINNINGS Richards Bay is an important geographical area for Dowson & Dobson Industrial, as it is home to numerous metal processing plants, the Richards Bay Coal Terminal, the sugar industry and large pulp and paper plants
Industrial products supplier Dowson & Dobson (D&D) Industrial expects its distribution agreement with industrial products supplier Pneumatic & General Supplies for Richards Bay, in KwaZulu-Natal (KZN) to expand its reach to industries that include the coal,...
INTERFACE OPTIONS The CTX ecoline machine practice-orientated SLIMline user interface is available with Operate 4.5 on Siemens 840D solution line or Heidenhain CNC Pilot 640
A modern computer numerically controlled (CNC) turning machine must be productive, flexible and easy to operate, says local machine tools distributor Retecon MD Hans-Peter Neth. He tells Engineering News that the new monoBlock and CTX ecoline series of machine tools...
SPECIALISED PURPOSE The Titan wall saws are usually used for the specialised demolition of reinforced concrete structures and on walls and floors
Professional sawing and drilling contractors have shown significant interest in the new Titan high-frequency wall saw, which is apparent in the several orders pending final financial clearance by companies, diamond tools and equipment manufacturer and supplier...
More
 
 
Latest News
Updated 11 minutes ago Investment in infrastructure and natural resources will continue to underpin economic activity in sub-Saharan Africa, although capital outflows sparked by tighter global financial conditions pose a risk to growth, the IMF said on Thursday. Inflation looks set to...
As industry prepares for the launch of South Africa’s digital terrestrial migration, the South African Communications Forum (SACF) hosted a workshop to determine the country’s readiness in terms of compliance of set-top boxes [STBs] and access to funding. The...
Higher Education and Training Minister Blade Nzimande
Higher Education and Training Minister Blade Nzimande has outlined plans for the development of a new health and allied sciences university into which the Medical University of Southern Africa (Medunsa) campus of the University of Limpopo, located in Ga-Rankuwa, will...
More
 
 
Recent Research Reports
Steel 2014: A review of South Africa's steel sector (PDF Report)
Creamer Media’s Steel 2014 report provides an overview of the global steel industry and particularly of South Africa’s steel sector over the past year, including details of production and consumption, as well as the country's primary carbon steel and stainless...
Projects in Progress 2014 - First Edition (PDF Report)
This publication contains insight into progress at the delayed Medupi and Kusile coal-fired projects, in Mpumalanga and Limpopo respectively, as well as at the Ingula pumped-storage scheme, which is under construction on the border between the Free State and...
Automotive 2014: A review of South Africa's automotive sector (PDF Report)
The report provides insight into the business environment, the key participants in the sector, local construction demand, geographic diversification, competition within the sector, corporate activity, skills, safety, environmental considerations and the challenges...
Construction 2014: A review of South Africa's construction sector (PDF Report)
Construction data released during 2013 hints at a halt to the decline in the industry during the last few years, with some commentators averring that the industry could be poised for recovery. However, others have urged caution, noting that the prospects for a...
Electricity 2014: A Review of South Africa's Electricity Sector (PDF Report)
This report provides an overview of the state of electricity generation and transmission in South Africa and examines electricity planning, investment in generation capacity, electricity tariffs, the role of independent power producers and demand-focused initiatives,...
Defence 2013: A review of South Africa's defence industry (PDF Report)
Creamer Media’s 2013 Defence Report examines South Africa’s defence industry, with particular focus on the key players in the sector, the innovations that have come out of the defence sector, local and export demand, South Africa’s controversial...
 
 
 
 
 
This Week's Magazine
The Electronic Systems Laboratory (ESL) of the Department of Electrical and Electronic Engineering at Stellenbosch University is strongly reaffirming its position as one of South Africa’s leading centres for satellite technology and expertise. It is currently...
MORE IN SA Phase 2 should see local content on the mainline locomotive increase from 65% to 80% by the end of 2014
The world’s lowest-cost diesel-electric locomotive is not made in China, but in Pretoria, at RRL Grindrod Locomotives’ newly upgraded 30 000 m2 plant. The company’s locomotive pricing is “more competitive than any other original-equipment manufacturer (OEM)...
The South African Defence Review 2012, released to the public at the end of last month (despite the year given in its title) recommends the creation of the post of Chief Defence Scientist. This official would be responsible for the management of defence technology...
AltX-listed engineering technology company Ansys has been awarded an R188-million contract by Transnet to supply integrated dashboard display systems to the freight rail utility’s locomotives. Black-owned and controlled Ansys developed the bespoke integrated system...
South Africa’s sole nuclear power station Koeberg, which is located in the Western Cape, breached a major operations milestone on April 4, which marked the thirtieth anniversary of Unit 1 having been connected to the grid. Eskom, which operates the two-unit plant,...
 
 
 
 
 
 
 
 
 
Alert Close
Embed Code Close
content
Research Reports Close
Research Reports are a product of the
Research Channel Africa. Reports can be bought individually or you can gain full access to all reports as part of a Research Channel Africa subscription.
Find Out More Buy Report
 
 
Close
Engineering News
Completely Re-Engineered
Experience it now. Click here
*website to launch in a few weeks