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[Eric Wong!]

... on a scanner?  There was nothing in the instructions.  There are a few places I can attach it.  Including- on the clamp itself, another "hole" in the bracket" or the bracket tightning knobs.

This mainly is for putting the light on/taking it off incase someone slips off the ladder cause I really don't think the 600 lb clamp will fail.  

The pic is unclear but I currently have it attached to the right bracket "knob".  It may not be the best choice, thus I'm asking here.

[Chad Costanzo]

On that scanner have the safety cable go under the yoke and around the pipe/truss that you are attaching the fixture to.  Yes, clamps do break.   I have seen a clamp fail and thankfully the fixture was saftied and no one got hurt.   ALWAYS use a safety....  

[Eric Wong!]

ah, makes sense.  I wound put the cable through another hole on the yoke next to the center clamp hole rather then under the whole yoke.  Would this be ok?  

I found this picture on wikipedia...

[Brian Ship]

[quote title=Eric Wong! wrote on Sun, 18 February 2007 17:55]ah, makes sense.  I wound put the cable through another hole on the yoke next to the center clamp hole rather then under the whole yoke.  Would this be ok?  

I found this picture on wikipedia...
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That would be a S-4 picture and not very specific to where to mount the safety cable.

Normally on a scanner type fixture with a slotted yoke, one would mount the safety cable thru the holes in the yoke.  This way, should even one yoke bolt break, and it just happens to be the side that the safety cable is on, than there is enough supplemtal force to bend the yoke up enough for the safety to slip around the bends in the yoke, you are covered by way of the holes in the yoke.  Safety cable won't slip thru the holes in the yoke.

If it didn't have holes in it, than the next preferred (given the fixture didn't have a safety cable ring to it) would be to slip the looped end of the safety cable thru the yoke and re-attache the yoke to the fixture.  This way you get a safety cable that's difficult to remove thus always there and more likely to if the yoke fails even on that side, have a safety cable grab the fixture still.


After that, as normal, the safety cable thru the yoke is a choice in it not being normal for first the clamp than the yoke bolts to fail.  But as opposed to it "not being normal" it's preferable as per on the S-4 fixture with it's safety cable ring (not labeled in the photo,) to if at all possible do similar.  This means find a hard point on the body of the fixture to mount some form of ring the safety cable can run thru or hole in the body of the fixture it can go thru type of thing.  Such a safety cable attachment point should not be in a easily shock loaded ripped out place and also be well away from anywhere a potentially longer bolt doing so might touch sensitive electronics or effect optics.  Safetys are much better thru the body if possible.  

Were it not for the shown easily safety cable holes in the yoke, I would possibly attempt a reinforced U-Bolt in the body of the fixture.

[Tony "T" Tissot]

The safety cable makes me feel better when it attaches to the body - protect from either the Yoke or clamp failure. (In an ideal world!)

Martin, as an example, has a set of holes (SCX) that are right in the body of the fixture (at the yoke attachment point).

Of course you can't find the right spot on most instruments. Or the manufacturer did not build them in. I have never been questioned by any inspector - as long as the safeties "looked" like they were in place.

ETC user manuals don't mention safeties.

[Eric Wong!]

I agree I'd like to attach it to the body too, however there's no where to put it short of punching a hole in the body.  Guess I'll stick to the cable thru hole in the yoke method.