[SML] Solenoids

[Chad Croteau]

HI Matt,

Everything Jon said I agree with wholeheartedly, and will add that you need
to not only consider the "clunk" at the end of the solenoid's travel, but
the possibility that it will give off a buzz or hum at the end of it's
travel.  Sometimes it's small, but I've used larger solenoids where it
sounded like a hockey arena buzzer.

I think Jon's idea of pneumatic cylinders is sage advice, as was the idea
presented by Nigel W. about using car door locking mechanisms.  My idea to
throw in the ring would be the door-holder electromagnets used in so many
buildings nowadays.  Quiet, strong and release the second power is cut to
the unit.

Hope this helps,


Chad


-----Original Message-----
From: Stagecraft [mailto:stagecraft-bounces at theatrical.net] On Behalf Of Jon
Lagerquist via Stagecraft

Matt,

My first advice is to not have the load on the actual solenoid shaft but to
connect a piece that can be support to take the side load....you can isolate
the solenoid into a sound enclosure.

Cable also provides the option to route the pull around things and back on
itself when doing drops with multiple points. And it allows you to stack
multiple control lines quite closely.

Given the option I prefer to use an air cylinder as my source of power, they
can develop a fair amount of force and getting a 3" stroke is easy. 
And they can be very quite.

However it is controlled it is possible to have operators tap the switch and
release it faster than the unit can activate. I have used various relays to
ensure an appropriate activation time. But the best is to teach the operator
to "push the button all the way down and hold it."