[SML] Motor controls in scenery

[Brian Munroe]

Was there an encoder/positional feedback device?  The controller should have shut down when it jammed - either some sort of positional tolerance error, encoder fault, or an over current error. In a properly designed system at least. 

If there was no encoder etc then I would think 2 limit switches in each direction as you described. 

Brian Munroe 

Sent from a rather small device with big fingers

> On Apr 7, 2015, at 4:26 PM, Bill Conner via Stagecraft <stagecraft at theatrical.net> wrote:
> 
> For installed motorized equipment, I've rarely not seen at least two
> limit switches at each end of travel - a normal end of travel and an
> over travel or ultimate limit.
> 
> What do you all do for scenery for a relatively short run production?
> 
> This was a one person platform lift - cable and drum pulling a
> platform up rails.  Single upper limit poorly mounted was not struck,
> nico and thimble jammed in pulley and the wire rope broke and person
> on platform plummeted the 6' or so to bottom.  Stitches, no permanent
> injuries reported.
> 
> Thanks!
> 
> -- 
> Bill Conner Fellow of the ASTC
> 
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