SourceFourPAR: melting lens tabs

[bshock84]

I just recently did a show and when I was pulling the gel out in the shop I saw a couple of my s4 pars had melted the tabs that hold the lens inside the fixture. They were melted to the glass, and when I pulled the gel frame the lens fell out.

Has anyone ever seen this? I wouldn't think it would get hot enough inside the lamp to melt the actual fixture, doesn't seem quite right.

They are the 750 watt versions.

Any ideas?

 

[Footer]

Yes, I have seen this. One of two things happened. First, someone put a 750w lamp in a 575 fixture. The second... and more probable... someone did not properly seat the lens in the fixture causing it to melt.

 

[MPowers]

The ETC S4 PAR MCM is rated only for 575 watts. The S4 PAR EA is rated up to 750w. However both use the same HPL lamp, so the MCM model can be over lamped. Is this possibly the issue?

 

[bshock84]

They are all EA models.

How can the lens not be seated right? Isn't there really only one way for them to go in there?

 

[Footer]

They are all EA models.

How can the lens not be seated right? Isn't there really only one way for them to go in there?

Yes, there is only one way. However, it is possible if you force it to have the lens press on the holding tabs instead of sitting on them.

 

[icewolf08]

They are all EA models.

How can the lens not be seated right? Isn't there really only one way for them to go in there?

It is also possible to put the lens in backwards (convex side out), though I don't know if this would cause the melting.

 

[derekleffew]

I once had a tour (of a famous star with a reputable lighting company) take umbrage and insist I was wrong when I told them their S4PAR lenses were in backwards (curve out).

bshock84, ask your favorite ETC dealer for Part#7061A4012 Lens Rotating Ring, Black. Surprisingly reasonably priced, and not terribly difficult to change.

 

[gafftapegreenia]

I once had a tour (of a famous star with a reputable lighting company) take umbrage and insist I was wrong when I told them their S4PAR lenses were in backwards (curve out).

Ya should have asked one of them to change a lens.

 

[bshock84]

I once had a tour (of a famous star with a reputable lighting company) take umbrage and insist I was wrong when I told them their S4PAR lenses were in backwards (curve out).

bshock84, ask your favorite ETC dealer for Part#7061A4012 Lens Rotating Ring, Black. Surprisingly reasonably priced, and not terribly difficult to change.

sweet, I will have to order a couple of these, I was wondering if I would be able to just change that out or not. I am pretty sure they were in right, it's not my first time using them by far, but I will keep an eye out from now on.

As far as putting them in backwards, that's just odd.

-- Ben

 

[Les]

As far as putting them in backwards, that's just odd.

-- Ben

Probably not as odd as you might think. I can see how someone might get confused, especially if one has never worked with or seen a S4 Par up close, and knowing that a par lamp is always convex side out. I think the concave look is a little odd but I can't say I've ever put one in backwards. With products out like the ADJ Opti-Par, which are designed with the convex side out like a normal par lamp, the confusion is compounded. I've never heard of a backwards lens melting the lens ring, but I have been told that it makes removing the lens a real pain (usually involving a flat-head screw driver and resulting in a chipped lens).

I believe it is possible to get the lens seated correctly, but not completely. This may go along the lines of what Footer mentioned. Perhaps some of the clips were snapped in place while others weren't, causing the lens to sit at a slight angle, thus bringing the plastic clips before the lens and exposed to more heat.

 

[GageStryker]

I can't say I've ever had them melted off... I'm thinking either bad lens alignment, like noted before, which, although difficult to do, is possible (make it idiot proof and someone will invent a bigger idiot). The other option is that there was something hot (like a moving head fixture) hung too close to it, but I think in that case you'd see other damage on the front of the fixture.

Maybe someone had a hard time getting the lens out and used a tool to try and pry it past the clips and pulled them halfway off and they melted the rest of the way?

 

[zailabouni]

I recently replaced 16 lense retainer rings out of 24 total source four pars (750). This was over 10 years of use. Talked to my etc rep and he said he hadn't heard of it. We only run 575s in our fixtures rated for 750, which made it even stranger. This facility has a lot of different amatuers operating the equipment and my best guess from the box full of extremely dark and burned through/melted gels is that people were running the dark gels for long periods of time. Dark gels, poor ventilation, and leaving dark gels on for too long can create a lot of heat.

Good news is, they are cheap and easy to replace, and important that you do. The lenses can fall out, especialy if the fixture is hung with the gel frame clip down and no gel frame in place. Plus a loose lense can create a strange throw. One note, make sure you take the time to clean the reflector (melting plastic makes a dark smoke that will coat the refletor) while you are changing the rings, and make sure to put the reflector back in the same orientation, it is possible to put the flector in upside down, the fixture will go back together but you will get light spilling out the seam of the housing. Hope this helped

The strange problem I ran into, the new rings and new or old clips did not lock in place in the ring. I had to cut a little bit off the little wedge thing that locks the clip in place and it seemed to work just fine.

 

[BillConnerFASTC]

Back around 2002 or 2003 I had 48 S4Pars installed in Orchestar Hall in Detroit, and lenses began falling. The explanation from ETC was a defective batch of plastic castings, and of course replaced them.

If I'm repeating, I apologize, but I belive the performance of the S4PAR with lense in or out is same, but it is simply easier to remove lense if concave and that is reason for that being the "right" way.