Re: Need speed switch for DIY funicular/hillside elevator

[nobody@xxxxxxxxxxxx (Dave Houston)]

If I understand correctly, you want something that will automatically
activate if the spool starts turning too fast.

Could you adapt this idea?

     http://www.msha.gov/S&HINFO/TECHRPT/HOIST/PAPER5.HTM

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


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