Subject: Re: [harryproa] Re: Rig questions, again
From: Rob Denney
Date: 1/8/2010, 4:36 AM
To: harryproa@yahoogroups.com.au
Reply-to:
harryproa@yahoogroups.com.au

 

True, which is why windexes, for example, have very small bearings.  However, the bigger it is, the more forgiving it is of alignment and squareness issues, and the less critical the bearing type (plain vs roller) so the less likely it is to jam.  I think.

rob

On Fri, Jan 8, 2010 at 4:54 PM, robert <cateran1949@yahoo.co.uk> wrote:
 

The way I see it. Less load per unit area but greater area giving the same total frictional force and on a larger moment arm therefore greater resistance to turning.



--- In harryproa@yahoogroups.com.au, Rob Denney <harryproa@...> wrote:
>
> 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@...> 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 <harryproa%40yahoogroups.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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