Re: Need speed switch for DIY funicular/hillside elevator

["ABLE_1" <royboynospam@xxxxxxxxxxxxx>]

Hello,

Don't know if this has been suggested but here goes.

In your desire to keep this a simple system to control a loss of cable or
drum think about this.

Since it appears that your tram is straight on an incline you could affix a
single cable between the rails from end to end.  This would be under your
tram.  On the tram bottom have it pass thru a spring loaded clamp apparatus
that would have a pivot lever with a protrusion thru the floor.  This
protrusion would have a foot pedal mounted on top.  The operation would be
that a passenger would just stand on the pedal which would release the clamp
on the cable thus allowing the tram to move.  If a disaster should happen it
would a matter of lifting your foot and the clamp would stop the tram.

Also your drive motor would or should have either a slip clutch or a
overload trip to protect the rest of the system.  With all in place you
could use it to help stop and hold at the other positions you have
indicated.

In some applications it is called a Dead Mans Stick or Switch.  Such as on a
train or trolley.

It may not work exactly as described above but it may start the seeds to
grow.

Good luck and great job.

Les



<astutesolutions@xxxxxxxxxxxxx> wrote in message
news:1162061065.466027.213040@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> 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
>