The Kimbolton Carrot-Crowning Machine
Current Progress
Almost finished (click to enlarge)
It works! (click to enlarge)
It works well! (click to enlarge)
As a result of the development of a successful machine, Heinz Wattie's, the major processor, has now made it a requirement for all its contracted growers to crown their carrots prior to harvesting. This has lead to the sale of six machines so far, with more to come.
COP Outcome development and evaluation
Problems and future developments
Despite the careful design and construction, extended testing and field-trials have revealed a few problems, which are being worked on.
The rollers are obviously crucial in fixing the cutting height. In certain conditions mud can build-up on the rear roller, causing it to increase in diameter and thus lift the cutting height. A simple scraper blade removes the mud, but causes increased torque and can cause the roller to stall and skid over the carrots, rather than roll over them. A two piece roller, with a gap in the middle, is being tested, to eliminate the problem.
The most serious problem, solved in later machines, was clogging of the lower bearing on each cutter shaft. These have been moved further up the shaft, away from the dirt and now give no trouble.
Regarding future developments, the wide variety of conditions encountered on New Zealand farms, and the individual preferences of farmers, means that a constant stream of suggestions for improvements and new features reaches the manufacturer.
Many of these can be incorporated into the design (at a cost) for individual customers, because the designer is also the builder. It is hoped to develop a “standard" machine, which can be built by sub-contractors at lower cost, which would satisfy the basic requirements of the industry, leaving the designer to concentrate on development, rather than production.
Possible future developments of the “standard" model include:
• Inclusion of height-of-cut markers on each jack – this would allow quicker and more consistent adjustment of the cutting height.
• Replacement of the shaft-and-gearbox drive by a hydraulic motor – this would allow the rotation speed of the blades to be adjusted independently of the forward speed of the tractor.This would be useful to cope with extra strong growth in the carrot tops.It would also make it possible to push the machine in front of the tractor,allowing a carrot harvester to be pulled along behind,thus completing the job in one pass.
• In-cab cutting height adjustment – this would allow the cutting height to be adjusted without stopping the machine,or leaving the cab.It is easiest to do this hydraulically,so this development would probably be implemented at the same time as the previous one.
• The implementation of any or all of these improvements depends on the continued commercial success of the machine, but with Australia just over the pond, this is not unlikely.
