Changes to the laminate being used to make the controversial Hemo Gorge roundabout sculpture mean more material than expected is needed.
A 12m sculpture is the final piece of the puzzle in completing the Hemo Gorge roundabout.
The sculpture was designed by Stacy Gordine, head of the National Stone and Bone Carving School at Te Puia, and is being 3D printed by Kilwell Fibretube.
Kilwell chief executive Craig Wilson said there had been some changes to the manufacturing laminate the sculpture was being made from.
The scale of this project is an entirely new concept for anyone in New Zealand, let alone the world.
"Our initial proposal was based on estimates which had to be confirmed by Gurit, our composite engineers in Auckland.
"Their report recommended some changes in the laminate which have increased the materials required," Wilson said.
But by refining the production process and securing better pricing on materials, the original price of $500,000 had stayed the same, Wilson said.
"There have also been some delays in starting the project due to getting the files prepared for the 3D printers but again we have identified more efficient ways of laminating and curing the composite laminates which will save us time," he said.
Wilson said the sculpture installation date might move depending on the weather.
"We will need a clear weather window for final assembly."
About 35 per cent of the sculpture has already been 3D printed.
Kilwell Fibretube took on the task of creating the sculpture in late 2017 after the original contractor was unable to create it.
Rotorua Lakes Council's arts and culture manager Stewart Brown said the printing of the sculpture was "well under way and on budget".
"The scale of this project is an entirely new concept for anyone in New Zealand, let alone the world, so it is understandable that a completion date is hard to pinpoint," he said.
"Initially the council estimated the completion date to be late August. However, the current status of the project means installation is more likely to be October, all things going well."
The sculpture is being printed by 10 printers at Kilwell's Rotorua factory and will take almost 16,500 hours to create.
It tells the story of two supernatural deities, Te Pupu (heat) and Te Hoata (fire), and their search for Ngātoroirangi, the great chief and priest of the Te Arawa waka.