3D PRINTING: DOING A GREAT JOB

Thank you for the outstanding job Popular Mechanics has done over the year in terms of sharing relevant and interesting information. I refer to your Skills section, May 2016, specifically the section titled “Getting started in… 3D Printing” on Page 87.

In my opinion as a project engineer in the 3D printing industry, you are selling us as South Africans short in terms of commercial 3D printing services available and where we are now with the technology. There are a few 3D printing service centres throughout South Africa. One of these is the Centre for Rapid Prototyping and Manufacturing (CRPM), located at the Central University of Technology, Free State (CUT) in Bloemfontein. The CRPM was established in 1997 as part of a research initiative and grew to become a centre that gives industry support. A laser sintering machine was imported from Germany – the fifth 3D Printing machine in South Africa. CRPM offers various printing technologies (selective laser sintering, stereolithography, direct metal laser sintering and polyjet) in a variety of materials (nylon, aluminium filled nylon, polystyrene, ABS simulation material, titanium and tool steel) for any industry or individual.

In 2012, the first South African 3D-printed implant (printed at CRPM) was successfully implanted in Pretoria. This was a proud moment for all concerned. Since then various implants have been produced and when the first mandible was implanted in the Kimberley Hospital in 2013, it received coverage throughout South African and in the global media.

CRPM has assisted 30 patients, who under the present circumstances, would not have undergone any procedures to restore their dignity and quality of life.

CRPM has been audited and recommended to receive ISO: 13485 (medical device) certification to manufacture custom implants, guides and models in titanium using 3D printing. This will make CRPM the first 3D printing centre in South Africa certified to produce medical devices.

Send your letter to: Howard Place 7450, or e-mail

Please keep it short and to the point. Regrettably, prizes can be awarded only to South African residents.

Remember that your electricity bill specifies the amount of energy used, by stating the amount of kwh units used and then bills accordingly.

If a load demanding 0,5 MVA is connected to an alternator with a capacity of 1 MVA, the load would have consumed 0,5 MVAH after an hour. The capacity of the alternator is still 1 MVA. (Excluding losses and power factor for inductive loads ) To summarise: An alternator will deliver what the load demands at any instance, provided that the load demand does not exceed the rated capacity of the alternator. The power consumed can then be related to time for energy calculation purposes or billing purposes.

Therefore, I maintain that the capacity of any generation plant cannot be time related. Time comes into the picture only when power is being consumed.