Re: Need speed switch for DIY funicular/hillside elevator

[Frank Olson <Use_the_email_links@xxxxxxxxxxxxxxxxxxxxxx>]

astutesolutions@xxxxxxxxxxxxx wrote:
> My dad and I built a homemade hill lift (in Europe refered to as
> funiculars) in Eastern Tennessee.  You can see a working demonstration
> and picture of it at:
>
> http://www.funimag.com/photoblog/index.php/20061026/a-do-it-yourself-funicular/
>
> The tram works fine, but I am trying to figure out some kind of simple
> safety mechanism in the event that the spools break loose from the
> gearbox or shaft and start rotating freely.  Since my wife and kids
> ride this thing, I'd like some kind of backup solution in the event of
> major catastrophe.  We are using 2 cables instead of one even though
> one can handle 5 times the max load, and we have a braking motor to
> stop, but both of those would be moot if the spool spins out of
> control.
>
> I am thinking of having some way of measuring the outfeed speed of the
> cable (or spool) and have some emergency brake apply if a limit is
> exceeded.
>
> Any suggestions?  I thought about putting fan blades at end shaft of
> the spool to have air slow it down, but that would be a little
> unsightly.  I'm looking for a simple solution, one preferably without a
> computer since this is outdoors and needs to be functional 100% of the
> time.  I'll take any flames in stride on this point.  I realize that
> this group is about computer automation, but its the only  one similar
> to this kind of project I could find :-)
>
> Thanks in advance.
> Jeff
>


I like Doug's idea of the automatic brake.  I also think you should put
solid sides on it to keep people from "dangling their legs" through the
railing like I observed in one of the movies.  I also think you should
employ some sort of gate, permanently mount the controller and
incorporate a safety switch that would prevent the device from moving
with the gate open.