Film-Tech Forum ARCHIVE: Failsafe Shutdown

This is topic Failsafe Shutdown in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Barry Floyd (Member # 385) on 01-10-2006, 10:40 AM:

I'm looking for a way to add a tensioning failsafe to both my booths. Currently I have NO type of automation whatsoever. Each night I turn everything on manually - one switch at a time.

In Booth 1, I have a Strong AP3 platter, a Simplex XL projector and sound head, and a Xenex II 4kw lamphouse.

In Booth 2, I have the same Strong AP3 platter, a Brenkert BX-60 projector,RCA 9030 sound head, and a Christie 4kw lamphouse.

I want to be able to have the whole system shut itself off in case of a brainwrap or something similar, but don't need alot of fancy bells and whistles.

Any ideas? This is all at a twin screen drive-in, if that makes any difference.

Posted by Brad Miller (Member # 2) on 01-10-2006, 10:53 AM:

You could either build a homemade tension failsafe or buy one already fabricated. Neumade makes an excellent one for this purpose. Since you don't have ANY form of automation, you will have to build yourself something out of relays to control the projector, lamp and platter power. (On the lamp, just wire it into one of the safety door closures, not the actual AC power.)

Honestly I think it would be cheaper to get a low end used automation and go from there.

Posted by Peter Mork (Member # 1336) on 01-10-2006, 11:07 AM:

I had the same need, and built a couple of tension failsafes out of junk we had lying around. I mounted a film roller on a pivoted arm, with a spring providing holdback tension - if there was a brainwrap, the tension on the film would build up and the arm would move and trip a switch wired to the automation. I'll try to put up a picture later in the week.

It works beautifully for a situation where the film is wrapping and tension increases gradually. Unfortunately if there's a jam at the brain it won't stop the system fast enough to keep the projector from doing some damage as it coasts to a stop.

I'll leave it to someone else to advise you how something like this could rigged to stop a non-automated system.

Posted by Dominic Espinosa (Member # 2122) on 01-10-2006, 01:12 PM:

Personally I'd pick up a used TA10/FM35.
I imagine all you really would automate is sound format right?
A little automation never hurt anyone.

Posted by Scott Norwood (Member # 30) on 01-10-2006, 01:24 PM:

Why not just connect the film failsafe to the lamp failsafe? Since you have a drive-in, the chorus of car horns will make an adequate substitute for for an alarm buzzer. [Smile]

Posted by Louis Bornwasser (Member # 3063) on 01-10-2006, 04:13 PM:

This is part of Installation. Whoever performed your installation should have at least left you with a way to cut off lamp & motor when the platter rollers drop. (Cost of one switch and 1 relay) Some wire up a bell to sound when the arm drops. (Add the cost of a bell and a switch to shut it down.)

Had this happened, you could easily add a tension switch to open when too much tension occured.

This is standard stuff; routine in every way. Suggest you talk to the guy who accepted your money. I would never leave anyone this way,. Louis

Posted by Peter Mork (Member # 1336) on 01-14-2006, 02:03 AM:

Here's my tension switch, mounted on a Speco. The spring's from a screen stretcher.

Posted by Chris Erwin (Member # 176) on 01-15-2006, 10:38 AM:

We use a Eprad Co-Operator with the "manual overide" option (wire a hot feed to the motor switch in case the relays crap and you're screwed)

Thing is as simple as your mama's washing machine. [Smile]

Horse traded for it and it does all we need to do. Monitors two fails. I've got a microswitch rigged in the head so if I lose the top loop, off she goes. Looks like someone missed a changeover. The other is in the soundhead.

Have Louis make you something and don't lose sleep over it again. [Wink]