Larger diameter is less prone to jamming with plain bearings and with properly aligned roller and bearings as there is less load per unit of area. Difficulty with the casettes is aligning them correctly. It is actually not that difficult (most machine shops can do it), but it is hellish expensive in marine materials so most are done less than perfectly. The cassettes can be a lot cheaper if they are made large enough, or the loads are small enough, to use balls as these are less prone to misalignment problems.
rob
On Wed, Jan 6, 2010 at 7:44 PM, robert <cateran1949@yahoo.co.uk > wrote:
I was under the impression that larger diameter bearings are more prone to jambing. I though that was the problem with cassette rudders
--- In harryproa@yahoogroups.com.au , Rob Denney <harryproa@...> wrote:
>
> > >Not sure what you mean but if it reduces those loads and >controls shape
> > it makes it interesting
> >
> A model is on the list of things to do.
>
> > > This appears to require either a large diameter lower bearing >or a bent
> > section. Both of which can make life difficult with the >engineering. not
> > sure how it would scale up
> >
> > Bent section. Actually an overwide sleeve so that it can be adjusted.
> Scaling it up is mostly a function of a lot of carbon. Better big boat
> solution is offsetting the mast in oversize bearings. Would have done this
> on Sol2 if the deck had been wide enough.
>
> rob
>
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