Shutter Catastrophie!

[Jim Cassedy]

The other evening, as soon as I opened the changeover shutter to put reel one of the
feature I was running on screen, a horrible noise came from the shutter housing of my
Century JJ. I immediately shut down the projector, I and could hear ominous scraping
noises as I tried turning it down by hand. I quickly realized this was not something that
I was going to be able to fix in a few minutes, so, at that point, after informing the
audience that there was some sort of "major problem", I wound up running the 35mm
show that night on one projector, stopping for reel changes.

I couldn't troubleshoot that evening, but the next morning, I discovered that the little 'stud'
that's 'peened' into the aluminum changeover dowser plate, had popped off, and it, and the
cable attached to it had somehow gotten sucked into the rotating shutter blades, severely
bending 3 of the edges. Due to other circumstances, I have not been able to attempt any
repair work so far.

I have thoroughly inspected the rest of the JJ mechanism, and aside from the broken
'stud' on the dowser plate, and the bent shutters, I can find no other damage. I inspected
the drive gears of the shutter shaft assembly under magnification, and they appear not to
have been damaged, since at no point did the shutters actually "seize" to a full stop.

My main question is:
> How advisable is it for me to remove the shutters and attempt to bend them back into
shape, until I can source a replacement? ( I know someone with a JJ they've been
cannibalizing, or I might be able to source one from BLS or someplace) By sheer luck, I don't
have any other 35mm shows this week, but I'm going to have to figure out something by the
following week.

BentShutter_1.jpg

BentShutter_2.jpg

BentShutter_3.jpg

(and if you know where I might be able to find a couple of replacement shutters,
I'm all ears! )

[Steve Guttag]

I would say, if you are handy with a hammer, anvil and perhaps some pliers, you should be able to get it back to usable until you source replacement blades. The blades were not that precise to begin with and had very little mass, relatively. It appears that one of the cooling fins got bent too...that may be more tricky to unbend though I believe it is the same part as on all Century bades. If you are running 35mm, for the time being, you also might be able to sub some SA shutter(s) (C1-D-48 or C1-D-49) to hold you over.

Ultimately, they are something that can be fabricated by a competent machine shop. I'd definitely check with BLS as they had to content with all things JJ related.

I recently had to fabricate a pair of Kinoton FP75E shutters and with suitable drawings, they just made them from the material I specified and came out nice.

[Brad Miller]

Beware if you use a Century SA shutter, you will almost certainly have smearing on the left side of the image when running 70mm, so that should be a 35mm only fix.

Also I would pull those 2 shutters off and use the shutter mount closest to the gate and put a single shutter there. Note this has to be a proper shutter, not those pictured above with the silly "V" notch. Your presentation will thank you for it, as you will get much more even illumination.

Also yes I know it was the pin that came loose, but there won't be a second shutter spinning in the opposite direction that could clash with the other if there should ever be an instance where the lamp is on and the lamphouse douser is open with the projector stopped for a moment which bends the shutter slightly.

[Mark Gulbrandsen]

All the older JJ's I've ever worked on had steel blades, including the original Cinerama 70mm JJ's. They don't really warp in the heat as the aluminum blades do, they can withstand quite a bit of light standing still, and when the machine is running, they add flywheel effect to the mechanism, which actually smooths out the projector a bit more. Since that's what they originally used, that's what I would look into getting made. No one projects 70mm with a 2KW lamp, except at home!

[Jim Cassedy]

[edited] Beware if you use a Century SA shutter, you will almost certainly
have smearing on the left side of the image when running 70mm,

I was wondering if I could temporarily use an SA shutter until I repair or get the bent ones
replaced. I too had some conerns about the bent cooling fin, and if I could get things bent
back into place without throwing the shutter shaft out-of-balance.

This is looking in from the lamphouse side, with the glass heat filter removed.
This is how I found it. I've never seen this happen before, and I'm not sure how
it managed to do so much damage. I had run some test loops the night before,
and ran the machines a for a few minutes before threading up, and all was normal



This is the culprit!


It should be attached here. I think it's just 'peened' in place.


For those unfamiliar with these things, it should look like this.



Fortunately, since this was a 'shutter problem' that occurred during the leader run-down
on the first reel, no film damage was done to the print (Brewster McCloud- 1970) since
it was moving normally through the machine. And also no 'film burn' on screen, since
the dowser shutter broke in the closed position, so no light ever got past the film gate.

Management later told me that nobody complained or asked for their money back due
to me having to run the show on one machine. I had a stopwatch running next to the
working projector, and the longest reel change took me 2m30sec, with most of them
taking appx 2:10. The crowd turned around and gave an extended applause at the end
of the movie, and many of them gave me a 'thumbs-up' as they left the auditorium.
(- - at least, I think it was their thumbs they were holding up...)

[Ryan Gallagher]

Sorry to hear about your crash!

We have an odd-ball single bow-tie shutter that doesn't match any of our units, like new spare, 70mm sized, though I believe it is an aluminum one and not a classic steel one. No cooling fins installed.

PS your second round of pictures is not loading for me.

My spare is the first image in the No. 10 reply in this thread:
https://www.film-tech.com/vbb/forum/...2885#post42885

I could maybe persuade our folks to donate it to a good cause, but you'd need a partner for it. I'm unsure if it was intended as an inner or an outer shutter. I agree with Brad that single classic shutter is probably the way to go these days unless you are a drive in needing the extra brightness.

Can confirm a SA Shutter might be a decent stop gap, but it won't be wide enough for 2:20 70mm prints. Though everything else should be fine. (I know cause I inherited one JJ out of two that was perhaps an SA in it's former life, with the wrong shutter for 70mm still installed). Either they'd been living with the left-edge ghosting or they focused the lamp to avoid it, killing brightness and field.

Please don't buy the last single 70mm shutters available from BLS. ;-) We'll need one by July at least as well. Ideally cause the opening angle is different than the two I have on my dual-unit, but in a pinch the two I have might work, just less room for shutter to be mis-timed.

[James Biggins]

As above. Second round of pictures not loading. "Invalid File Specified".

[Jim Cassedy]

I'm not sure what happened to those photos. Two computers here show the pictures,
but one doesn't- - which is odd. But anyway I'll try again & hopefully these will work:

This is looking in from the lamphouse, with the heat filter removed.
This is how I found it when I first started investigating to see what happened


This was the culprit!



It should be attached here. I think it's just "peened" in place.


It's supposed to look like this:

[Tony Bandiera Jr]

Jim, photos still not working. Maybe email Brad and let him know...

[Mark Gulbrandsen]

Ryan,

These are obviously the steel blades. It's about impossible to tell if they are actual Century, or are replacements made by Wolk. Either are very good. Aluminum blades don't rust.

[Mark Gulbrandsen]

Jim, photos still not working. Maybe email Brad and let him know...

Tony... Either Brad fixed it, or It's something on Ryan's end, my post worked fine.

[Vern Dias]

No, it's still not working.....

This is the link for the first photo: https://www.film-tech.com/vbb/fileda...iledataid=5195

and this is the message I get trying to open it in another browser window: Invalid File Specified

Using Firefox. Just tested, same response in chrome as well.

[Ryan Gallagher]

Ryan,

These are obviously the steel blades. It's about impossible to tell if they are actual Century, or are replacements made by Wolk. Either are very good. Aluminum blades don't rust.

Those were the ones on the unit, I was referring to our loose spare (different photo). Annodized black and very light weight. (Also lacking the riveted on cooling fins).

Perhaps I used the terminology "bow-tie" referring to the wrong ones and you looked at the other photo. Bow-tie is classic and V-Notch is the dual shutters like Jim's?? (Like my spare floater).

[Mark Gulbrandsen]

Yes, I saw that one. It doesn't appear to be quite wide enough to work on its own. Compare it to the length of the steel blades. You would need a second blade, and it may be out of a Centruy DAW 35mm machine. While JJ's can work single or double, they were originally designed to work double for faster light cutoff and a little bit higher light efficiency.

[Ryan Gallagher]

Yes, I saw that one. It's not quite wide enough to work on its own. You would need a second blade. While JJ'scan work single or double, they were originally designed to work double for faster light cutoff and a little bit higher efficiency.

Haha yeah. My original questions were answered in my thread, I was considering offering my spare loose V-Notch to Jim, but he would need a partner for it. (If he was trying to replace his two V-Notch shutters). I can confirm it is the diameter that matches my installed 70mm shutters though, not the smaller 35mm/SA type shutter diameter.

But it sounds like the consensus would be to avoid aluminum shutters in the larger houses with >2K+ lamps. So not much use to him either I expect.

But if Jim's are aluminum now, my spare seems to match his outer shutter (that lacks the cooling fins).

PS still no Jim photos loading on my end other than the OP in chrome. I tried firefox but then promptly got my account locked for 15 min after failing to remember my password. lol