Re: Need speed switch for DIY funicular/hillside elevator

[astutesolutions@xxxxxxxxxxxxx]

Thanks for all the good ideas guys, sorry I haven't responded to all of
them yet.

Les, yes, I tried to check, even looked at some of the others that sold
kits for hillside lifts and they only wanted to sell the whole package,
not their speed regulators.

Bill has a good point about shutting the system down if the "mousetrap"
is triggered.  This is very possible because there is an emergency
cutoff switch near the spool (not shown, recently added) and if that
circuit is opened, the whole system shuts down.  A jumper in series
with the switch could shut it down if pulled.

Someone on another board made an interesting suggestion.  He mentioned
a go cart clutch.  When I looked into it, the go cart clutch (GCC)
activates when the rotational speed gets up using a centrifugal setup.

See:  http://www.gokartsupply.com/clutches.htm

So here's what I'm thinking.  On the end of the spool, have a large
sprocket that drives a chain to a smaller sprocket.  The smaller
sprocket is hooked up to a go cart transmission (centrifugal clutch)
that is underneath the drum units.  The gearing would mulitply the
spin.  At high speed rotation, the clutch engages and the wheel turns
and yanks the mousetrap and pulls out a jumper that opens the emergency
stop button (motor shutoff).  Then it would take a manual reset to
unlock, but if its spinning freely something major is wrong such as a
broken coupling or a broken shaft inside the gearbox.

ABLE_1 wrote:
> This has all be a fun exercise of the grey matter.  Which needs exercised to
> maintain some functionality in life.  Well then it hit me.  Why re-invent
> the wheel.  Since these funiculars have been in operation all over the world
> for quite some time, I thought that it would be good to look at what the big
> guys are doing.  My hope is that Jeff has already looked into this at some
> point in time.  It might prove beneficial if some of the companies were
> contacted to get some input of what safety system they use on their
> equipment.
>
> This link is for a number of manufactures
> http://www.funimag.com/Funimag-Manufacturers.htm
>
> And this one talks about there safety features
> http://www.accumar.com/safety.html
>
> Again Good Luck,
>
> 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
> >