Re: Need speed switch for DIY funicular/hillside elevator

["ABLE_1" <royboynospam@xxxxxxxxxxxxx>]

Jeff,

It does get a bit challenging does it not.  Diverting from the simple a bit
you could consider this.

Since you have already made the wireless for control of the unit could you
then incorporate a solenoid on the deadman switch that would override the
foot pedal for a one-time trip.  This could be set up in relay logic that
would respond off a momentary push button at either end.  Once the tram
reached its new position it would trip a limit switch and return all
functions to normal.  It would require that some power on the tram but this
could be accomplished with a battery with some indicator when the battery
gets low.

I can see some problems since this will not be 100% fool proof.  (or idiot
proof as some would say) but you can do some rigorous training of family an
friends since this is not for public use.

Good luck,

Les





<astutesolutions@xxxxxxxxxxxxx> wrote in message
news:1162098544.821564.137120@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
> Les, thanks.  The fixed cable with a spring clamp is something I
> thought of, the only problem is that the deadman switch wouldn't work
> because part of the design is that there is a call button at the top
> and bottom to recall the cart in the event it is at the opposite end.
> It was also suggested that a mechanism such as this could release when
> the cable tension was released, but due to the stiffness of the cable
> and how the cable is already somewhat slack when the cart travels down,
> it makes it hard to set up the trigger, with the exception of if both
> of the "pull" cables broke.
>
> I do think that the fixed cable is about the only way the cart could
> have something to "grab" onto similar to the method you describe.
> Grabbing the rails would be difficult because the sides are circular
> (pipe) and there are angle iron pieces that extend beyond the plum part
> of the pipe leaving less than half of the pipe to grab.
>
> What would be nice is if there was a way to have a pulley mechanism on
> the cart that spun a cog or something such as a pnuematic pump that the
> faster it went it applies more force to say a brake caliper that would
> grab the fixed cable, as suggested by Doug earlier.
>
> Thanks!
> Jeff
>