Quarrying & Mining Magazine

Crusher modelling

Peter Fraser is best known for his modified Kumbee Hammermill design, but his perfectly scaled crusher models are works of art.

BACK IN THE 1970s and 1980s Peter and his father Jock were well known industry identities in the Hastings area where they operated a contracting and transport business, John Fraser and Sons Contractors, plus an alluvial quarry at Mere Road at Fernhill, Hastings.
John Fraser and Sons merged its interests in 1972 with HB Transport Holdings, and Peter was assigned the job to design and build Fraser Shingle on the land at Fernhill. He was 36 years of age. The quarry is still operated by Holcim. The ‘Fraser modified design’ is still being used throughout New Zealand, Australia, and South Africa and featured in the March issue of Contractor magazine. There’s a Kumbee still at use in the Winstone Aggregates plant at Fernhill, where Peter’s son works.
Now, in his early 80s, Peter enjoys lengthy times at his beach house playing snooker and making models. Although never trained as an engineer, Peter is capable of drawing very professional plans.
A passionate hobbyist, a few years ago Peter got an inkling to make scale models of quarry plant and equipment that he used at Fraser Shingle. He started building them in 1/10 scale and got the original plan of the Kumbee from Holcim. With his technical drawing skills, he says he had no trouble in drawing new plans in 1/10 scale.
For the main body of the model he used 1/8 Perspex. The breaker plates are all cast in resin after making a mould using RTV rubber.
The liner plates were made from 1/8 Perspex and bolted into place using BA bolts and nuts and washers that are all made to scale.
The rotor disc he turned on his home workshop lathe from various 1/8 Perspex, while the shaft was made from brass complete with threaded locking nut as per the original drawings.
The hammers are made from various thicknesses of plastic strip and the shanks cast from resin.
The base for the models is the same as for the Barmac Rotopactor. He was fortunate to have a copy of the original plans from Tidco. The base was constructed from plastic sheet, the deck from mesh as used by plasterers, the hand rails and ladder from Plastruct plastic, strip and rod.
The conveyor has a vulcanised rubber belt. All the rollers are made from brass tube and are able to rotate. “A very labour-intensive job, believe me,” adds Peter.
The electric motor was made from a piece of one and a half inch plastic pipe with the fins added from plastic strip.
The fan cover is from the bottom end of a pill bottle with mesh from a piece of fly screen.
The bearings were made to scale with brass tube and cast in resin.
Peter’s interest in the model 56 Kue Ken began back in 1965 when his father Jock took a truck to Andrews and Beaven in Christchurch, purchased a portable crushing plant and towed it back to Hastings.
Peter began making his 56 Kue Ken jaw crusher models by photocopying plans from the original Kue Ken Armstrong Whitworth manual on his daughter’s photocopier.
The dimension of the full-size machine is 720mm, with the man-frame made from 1/8 Perspex sheet with the swing and fixed jaw from plastic sheet. The red fly-wheel is made from a piece of 70mm plastic pipe.
The cast lettering on the fixed jaw, proved a challenge Peter says. The letters are made using plastic strip and glued down individually.
“When I got to the ‘S’ in ‘crusher’ I found I couldn’t bend the plastic strip without breaking it.” Peter Fraser was not going to be beaten, “so I took a piece of brass wire, made an ‘S’, then filed it flat on both sides”.
“Just to make sure it stuck, I glued it with super glue.”
Peter Fraser is currently working on a Barmac MK11 Rotopactor model complete with Tidco stand.
A quarter segment of the crushing chamber will be removed so as to see the rotor in position. The 150 electric motor on the model was made from drawings that were supplied be WEG Electric Motors of Matamata.
Peter says his next project is to tackle a 16×8 or 16×12 Hauraki single togged jaw crusher manufactured by A&G Price of Thames. Peter’s father Jock built and operated two of these crushers in the early 1950s and 1960s; one was in a fixed plant and the other portable.
A&G Price is no longer in business and so if there is anyone amongst our readers who may have one in the retirement section of their quarry then Peter would appreciate a photograph so he can measure up and scale his model. Please phone him on 06 877 1013.  

This article was first published in the April-May issue of Q&M.

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