Why a Nichols concave will transform
your combine's performance

A combine's output is limited by its ability to separate threshed grain from the straw as the crop passes over the straw walkers or rotary separator. The more the straw is damaged in passing through the drum, the softer it becomes and it lies more heavily on the straw walkers, forming a mat through which thrashed grain cannot pass easily.
The Nichols concave, designed in Australia but now made in Somerset, dramatically reduces straw damage in
the threshing area so that the mat of straw on the walkers is less dense and fluffier allowing grain to pass through more easily. This has several benefits:

• the harvesting capacity of the combine can be increased by 10% or more

• the improved straw quality is better for
bailing

• less straw damage allows for a huge
reduction in the returns, as much as
75% in some cases

• because the grain is subjected to a
longer more gentle thresh, no de-
awning plates are required (fitting
these only restricts output)

• because the straw is not hammer
milled in the drum, the power
requirement is greatly reduced,
resulting in better fuel consumption,
less wear and tear, and more
available power for other combine
activities such as straw chopping,
auger unloading etc.

This output and quality is achieved by
manufacturing a concave which is much stronger than the original production
equipment. The Nichols concave is at
least 10 times stronger and weighs
approximately 70% more. The front bar of the Nichols is manufactured from
armour plated steel, the remaining bars from structural grade steel and the
wires from spring steel.
Most standard concaves will flex and bend up to 15 mm under load making it impossible to maintain consistent
threshing action, and resulting in the
'woof woof' noise when overloading
occurs. Consequently many standard
concaves are permanently bowed or
broken, producing cracked grain and
damaged straw. The Nichols concave's strength and rigidity produces an even
thresh across the full width of the drum, improving grain and straw quality.
The constant parallel gap between the concave and drum reduces the risk of damage to those components from
stones etc, because if a stone gets in it will pass straight through.