Re: Need speed switch for DIY funicular/hillside elevator

["Robert L Bass" <robertbass1@xxxxxxxxxxx>]

Going back to Doug's suggestion, you could install a pivoting arm with a pulley on the end to take up slack in the cable on the
uphill side of the tram.  The arm would need a hydraulic or spring-loaded strut to draw it up toward the tram.  Slack feeding out
beneath the tram goes up over the pulley.

The arm mechanically holds open a brake as long as it is stretched down, where it will always remain if there is tension on the
cable.  If the cable breaks the arm swings up, activating the brake.  The can either be on a third cable or on the wheels.  A cable
brake should be easier to implement than wheel brakes, but the end result is the same.

The advantage to Doug's idea (as I perceive it) is that it is simple, requires no electronics and should be easy to maintain.  Trial
and error should quickly yield the amount of tension required to operate the arm and the brake.

Note about safety factors.  When "flying" live actors or moving loads above a stage, I would select equipment rated to hold 10 times
the static weight of the load.  This would allow me enough margin of safety to stop a load even as it gained momentum before
reaching the end of the safety cable.  On a slope the load doesn't gain momentum as quickly as on a deadfall.  However, depending on
how quickly your safety system detects a failure and engages and the slope of the rails, the tram could accelerate, perhaps to the
point of failure of the emergency braking system.  Not knowing the weight of the tram, number of people who will be riding at one
time, slope of the hill, etc., I can't say how strong is strong enough.  It sounds as though you've given this careful
consideration, but double-checking your calculations is never a bad idea.

--

Regards,
Robert L Bass

=============================>
Bass Home Electronics
941-866-1100
4883 Fallcrest Circle
Sarasota · Florida · 34233
http://www.bassburglaralarms.com
=============================>

--

Regards,
Robert L Bass

=============================>
Bass Home Electronics
941-866-1100
4883 Fallcrest Circle
Sarasota · Florida · 34233
http://www.bassburglaralarms.com
=============================>