On Thu, 12 Nov 2009 00:04:04 +0000, geoff wrote:

To clarify, the shaft is D-shaped all the way along hence manual filing
could be problematic...?

But why ?

Surely the flat is only required at each end

Hi Geoff,

The 'flapper' has a D-channel all the way through it and whilst you could
just poke the shaft in by only a small amount this would work fine when
free-running. However, when food starts getting caught between the rubber
flapper blades and the container walls the torque required to turn it
increases significantly. At this point the plastic centre of the flapper
really needs a good grip on the shaft hence the more that's in there the
less the likelihood of something rounding off at this interface.

Mathew