Re: Need speed switch for DIY funicular/hillside elevator

[nobody@xxxxxxxxxxxx (Dave Houston)]

Look here also for other general ideas...

     http://en.wikipedia.org/wiki/Dynamometer

One possibility would be a small air compressor that would be driven by the
spool shaft with a discharge to the atmosphere through a fixed orifice. At
slow speed there would be little resistance but as the speed increases the
resistance increases, slowing the spool. You want to be sure that everything
is sized to be safe - you don't want the compressor or any associated pipes
to burst. You might even let the discharge drive a whistle to warm anyone
nearby.

astutesolutions@xxxxxxxxxxxxx wrote:

>
>Dave Houston wrote:
>> 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:
>>
>
>Dave, yes, that is helpful.  It demonstrates many techniques I can use.
> Althoug I'm still limited as to how to build a similar system myself,
>it should give me some more terms to google to see if there is an off
>the shelf solution I may be able to adapt.
>
>I especially liked the rope brake discussions.  Although their solution
>used compressed air, I could use some kind of spring powered mechanism
>(on cart) to clamp down on a fixed cable that runs from top to bottom.
>I'm still at a loss though as to how to easily trigger it on the speed,
>although obviously a simple solution may be out of my reach.
>
>Thanks for the link!
>Jeff


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