Conventional Fixtures Pan Bolt Discussion

Esoteric

Well-Known Member
It was referred to as a set screw in some old Altman literature so Amarante and David taught us to call it that.

Pan lock bolt is a misnomer since you should never use that bolt to adjust the pan of a unit.


Mod Note: This thread branched off from an original discussion that can be found here
 
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Re: New Lighting Blog Series: Types of Units

Pan lock bolt is a misnomer since you should never use that bolt to adjust the pan of a unit.

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Re: New Lighting Blog Series: Types of Units

Because its what holds the fixture to the C-clamp, although I have seen C-Clamps without the set screw. This would require one to use the yoke bolt to adjust left and right movement. Its also really tough to get them back to how tight they are supposed to be when they are in the air... (could also throw your focus of the unit off as well).
 
Re: New Lighting Blog Series: Types of Units

Because its what holds the fixture to the C-clamp, although I have seen C-Clamps without the set screw. This would require one to use the yoke bolt to adjust left and right movement. Its also really tough to get them back to how tight they are supposed to be when they are in the air... (could also throw your focus of the unit off as well).

Actually the yoke bolt is what holds the fixture to the C-clamp. The pan bolt just keeps it from spinning. There's a great pic in the wiki if you click on the word C-clamp anywhere in this thread.
 
Re: New Lighting Blog Series: Types of Units

Actually the yoke bolt is what holds the fixture to the C-clamp. The pan bolt just keeps it from spinning. There's a great pic in the wiki if you click on the word C-clamp anywhere in this thread.

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So, in theory, unless you have the c-clamp at an angle where the pan bolt kept the unit upright. (if that makes sense to you...sounded better in my head, but I don't know how to re-write it.)

The shaft/spigot shouldn't come out of the clamp with a fixture attached regardless of the pan bolt.
 
Re: New Lighting Blog Series: Types of Units

Okay, I strongly discourage my techs from panning the unit with the set screw. It is too easy to break the head off, it is very easy to pull all the way out and strip it putting it back in, it is easy to create grooves in the shaft which effect focus, sometimes it takes too long to het a wrench on it when you can do a yoke bolt focus with just your hands, eventually the bolt will not tighten fully anymore.

There is a laundry list of reason not use it for focus.
 
Re: New Lighting Blog Series: Types of Units

Yes, if your space has clamps with shafts that DO NOT have a safety lip to prevent it from free-falling when loosened, I strongly suggest getting them replaced.
How about these?
C-clamp studs.jpg
No "safety lip"; the one on the left has a roll pin, the right a pound rivet, do they need to be replaced also?
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I agree, thinking of a set screw as a threaded screw without a head for an adjustable wrench, usually uses an allen key or slot for a screwdriver and can be set into the sleeve of the item it is screwed into. Of course, I could be wrong here.
See this post. If/when you seek a replacement, you'll need to ask for a "cup point square head set screw" for both the pan screw and pipe bolt.

On most of the clamps I see/use, we use either a bale block, ...
WTH is a "bale block"? I've (rarely) heard "bale" used synonymously with "yoke," but never heard bale block. And why does one bail water, yet bale hay?:confused:
 
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Re: New Lighting Blog Series: Types of Units

How about these?
View attachment 5367
No "safety lip"; the one on the left has a roll pin, the right a pound rivet, do they need to be replaced also?

What I meant about a safety lip was a device-such as those two examples to prevent free-fall. So my point is really only about safety not type of safety device. If someone or vibration can loosen a bolt on a hanging fixture or hardware and it comes loose enough to fall out of the clamp, it just seems dangerous to me, that's all. Yes cable safeties are always needed as well, but that doesn't help the electrician on a ladder, who has to hold up the unit weight with one arm while panning.
 
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Re: New Lighting Blog Series: Types of Units

Why would someone try to pan a unit hanging on by its safety cable?
 
Re: New Lighting Blog Series: Types of Units

Okay, I strongly discourage my techs from panning the unit with the set screw. It is too easy to break the head off, it is very easy to pull all the way out and strip it putting it back in, it is easy to create grooves in the shaft which effect focus, sometimes it takes too long to het a wrench on it when you can do a yoke bolt focus with just your hands, eventually the bolt will not tighten fully anymore.

There is a laundry list of reason not use it for focus.
While I do agree there isn't just one way to do this, IMHO that isn't a good laundry list.
If the tech is breaking off the pan bolt(not a screw, I know just a silly technicality, but hey what are words for) they need better training, or the bolt was already previously over-tightened and needed replacement. I feel it shouldn't take even a quarter turn to lock it tight. Yes, too many people whomp on bolts with their wrenches-especially on truss. Again training.
Pulling all the way out? Hmm, I thought, that's never happened to me or anyone working with me; I just counted 10 1/2 FULL 360 degree turns to get the bolt to 'come out' of the clamp. If you have shorter bolts, I'd replace them. Cross threading on reinsertion: bad technician or bad bolt. I just tried but was unable to get it to cross thread. Creating grooves in the shaft? Again someone has improperly over tightened in the past. Loosen the yolk bolt and the pan bolt, spin the shaft to a clean area, re tighten with just the appropriate amount of torque this time. If the whole shaft is chewed up replace it.
While I can appreciate panning a parcan by hand, yes I've done it for my whole career starting on touring rigs while hanging in the truss above the stage, but I always had my wrench out as well. If the yoke bolt isn't just right it will end up way too loose at times anyway, thus needing the wrench. Which, as I do is hanging from my wrist by a safety lanyard anyway, so time is NOT a good reason. This is borderline lazy. There are many many Gaffers & Designers who will tear you a new one for just hand forcing a pan or tilt. They demand you use a wrench, we feel if you hand force it, you are setting it up so it may inadvertently move during the show, or your actions are contributing to the damaging of the gear.
The last part you state: eventually the bolt will not tighten fully anymore.
I don't understand that except, as with all the above, gear MUST be maintained properly, and taken out of service of it needs it. Low or no budget shouldn't be used as an excuse for unsafe practices.
 
Re: New Lighting Blog Series: Types of Units

Why would someone try to pan a unit hanging on by its safety cable?

I believe Gern was specifically referring to panning a unit lacking a safety lip, pin or rivet using the set or pan screw- which is indeed the proper way to pan a unit. Not always the most convenient.... It is still often more easily done, though, (especially with well maintained C-Clamps) as the motion by which it is locking occurs should only require one hand exerting force; locking the pan on a unit via the yoke bolt will usually result in torquing the unit clockwise with the bolt. Also, unless the unit is side hung, this means that one is working with gravity to place and hold the tool being used and to move the screw. The usually results in overall higher probability that all adjustments are properly locked against unintended refocusing by occurrences such as being hit with scenery or by carpenters or being shaken on their position.
 
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Re: New Lighting Blog Series: Types of Units

We've wandered so far off the original topic.:( I thought moderators were supposed to prevent that?:rolleyes: Some days, it's like herding cats (or wrangling stagehands).
 
Re: New Lighting Blog Series: Types of Units

While I do agree there isn't just one way to do this, IMHO that isn't a good laundry list.
If the tech is breaking off the pan bolt(not a screw, I know just a silly technicality, but hey what are words for) they need better training, or the bolt was already previously over-tightened and needed replacement. I feel it shouldn't take even a quarter turn to lock it tight. Yes, too many people whomp on bolts with their wrenches-especially on truss. Again training.
Pulling all the way out? Hmm, I thought, that's never happened to me or anyone working with me; I just counted 10 1/2 FULL 360 degree turns to get the bolt to 'come out' of the clamp. If you have shorter bolts, I'd replace them. Cross threading on reinsertion: bad technician or bad bolt. I just tried but was unable to get it to cross thread. Creating grooves in the shaft? Again someone has improperly over tightened in the past. Loosen the yolk bolt and the pan bolt, spin the shaft to a clean area, re tighten with just the appropriate amount of torque this time. If the whole shaft is chewed up replace it.
While I can appreciate panning a parcan by hand, yes I've done it for my whole career starting on touring rigs while hanging in the truss above the stage, but I always had my wrench out as well. If the yoke bolt isn't just right it will end up way too loose at times anyway, thus needing the wrench. Which, as I do is hanging from my wrist by a safety lanyard anyway, so time is NOT a good reason. This is borderline lazy. There are many many Gaffers & Designers who will tear you a new one for just hand forcing a pan or tilt. They demand you use a wrench, we feel if you hand force it, you are setting it up so it may inadvertently move during the show, or your actions are contributing to the damaging of the gear.
The last part you state: eventually the bolt will not tighten fully anymore.
I don't understand that except, as with all the above, gear MUST be maintained properly, and taken out of service of it needs it. Low or no budget shouldn't be used as an excuse for unsafe practices.

The difference between tight and broken on the set bolt can be as little as less than 1/4 turn. I assure you I am a very well trained electrician and I have broken at last a dozen in my career.

The last part is funny because I yell at people all the time for loosening the set screw to focus.

Add another reason because it causes the unit to rock creating an improper and difficult focus.
 
Re: New Lighting Blog Series: Types of Units

The difference between tight and broken on the set bolt can be as little as less than 1/4 turn. I assure you I am a very well trained electrician and I have broken at last a dozen in my career.

The last part is funny because I yell at people all the time for loosening the set screw to focus.

Add another reason because it causes the unit to rock creating an improper and difficult focus.

Yep, multiple ways to do things, that is for sure!
Once upon a time I set a 407(Mole 1K fresnel) on a stand up around 7' from the floor. As I was trained, I did a strain relief loop in the cable then hooked it to the fixture using the built in cable rope. During focus Bo... Dicki.... went to the unit, wanted to tilt it up, and just pulled the power cord down. It didn't tilt up. When he look at the head and saw the cable wasn't just hanging free, he exploded screaming "Somebody doesn't know what the #@*! they are doing!" He was right of course: I didn't know that what I was doing was making it impossible for him to just yank on a power cord to change his focus...
See http://www.controlbooth.com/forums/lighting-electrics/19893-lighting-designers-vs-board-ops.html
Of course:
1 He is the designer.
2 He is respected by far for people than I am.
3 He makes way, way, way... more money than I do.
4 I will always still put a loop on a fixture when on a stand. More than one if it gets hung on a pipe, so as to be moved quicker.
 
Re: New Lighting Blog Series: Types of Units

We've wandered so far off the original topic.:( I thought moderators were supposed to prevent that?:rolleyes: Some days, it's like herding cats (or wrangling stagehands).

Fixed because I heart you.
 

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