Film-Tech Forum ARCHIVE: Kinoton FP30D Changeover shutter problem

This is topic Kinoton FP30D Changeover shutter problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Matt Frankish (Member # 2131) on 01-12-2004, 07:02 AM:

Hello all - new to the forum.

We have here (David Lean Cinema, Croydon, UK) two Kinoton FP30D projectors which we use with a change-over midfilm. The Blackout shutter in one of them (but only one) is very slow to operate at the ned of a film (or at a changeover point, but we now do the changeovers the other way round to avoid this problem)We don't, however, get this problem at the end of the ads, so I'm guessing the problem is to do with heat - the projector gets much hotter during an hour film than 15mins of ads.

Any ideas what may be causing this? The shutter itself has been replaced. Let me know if you need any more details to help: here's a quick rundown.

Kiniton FP30D projector
1600w Xenon in 2k Lamphouse
Cinemechannica 2k rectifier
Operated by a wired remote box.
Each runs every day for approx 4 hours (ie: 8 hours of screen time a dsay spread across 2 projectors)
The other projector which is nominally identical doesn't have the problem.

Thanks in advance

matt

Posted by John Wilson (Member # 269) on 01-12-2004, 07:39 AM:

Hi Matt

Remove the shutter cover and take a look at the rubber stopper on the end of the c/o shutter mechanism. You will find (I believe) that the heat has made a flat spot on the rubber stopper. If you use an allen key to undo it slightly and turn it to a round, undamaged spot your problem will be solved.

It heats up and goes sticky during a feature, but the heat from just ads and trailers isn't enough to make it stick.

A good extractor and a nice cool booth will slow this down.

Hope this helps you out.

John

Posted by Michael Schaffer (Member # 1204) on 01-12-2004, 07:47 AM:

I also sometimes had problems with the dousers not operating quickly when overheated. Do you have the heat filter installed? That is the plate of coated glass in the front of the lamphouse. The coating has to face the xenon lamp. Do you have the front gate (the black shield with the octogonal cutout) installed?

Posted by Stephen Furley (Member # 1277) on 01-12-2004, 08:06 AM:

Matt, you've had that problem for quite a while, haven't you, it was like it when I last ran those machines, some months ago now, but as far as I remember, it was ok the previous time I was there, a year or so before that. If I remember correctly, it's the right hand machine, and opening is ok, it's just closing that's slow, is this correct?

Did it suddenly happen, or did it gradually get worse? Kinoton changeovers do seem to be rather sluggish generally in my experience, but that one was certainly worse than usual.

Steve Wilsher warned me about it, but I tend to run adverts and trailers on the right, and start the feature on the left anyway, but it still seemed slow to me, when closing after the adverts.

I wouldn't have thought it would be a great deal hotter after an hour than after 15 minutes. Is the 1600 Watt figure correct, I thought you were on 1k lamps, or am I thinking of somewhere else? Either way there's not a great deal of heat there. How is it when the machine is completely cold? It's not a remote box problem, it's just the same from the buttons on the column.

I've run plenty of Kinotons, but I haven't looked inside one for years, and I think the ones I have seen inside were all early 20s, they may have changed the design since then. Are they solenoid opened and spring closed?

[ 01-12-2004, 11:49 AM: Message edited by: Stephen Furley ]

Posted by Steve Guttag (Member # 268) on 01-12-2004, 08:56 PM:

Since you say they are FP-30Ds, I would presume you have the modern change over douser (spring return). The older ones that had a sea-saw type are junk and should be replaced if at all possible.

Kinoton, has had various circuits for controlling the current changeover douser. The earlier style circuit had an elaborate scheme to use a capacitor to prevent the back-emf spike from harming the changeover relay...if that is the case in your machine (this circuit is on a plug in PCB....then you should nix it...it isn't necessary. The same goes for the open circuit. All it really needs is the relay to open/close the douser.

The close speed can be modfied by how much spring tension is on on the douser arm. There should be an air-pot to cushion the closing force and it can be adjusted such that the douser closes with a dead stop (no bouncing).

The only time I've had poor performace with this douser is actually on opening if it is heated up too much (i.e. run a 3K lamp on it for a minute or so).

Steve

Posted by Chris Byrne (Member # 1563) on 01-13-2004, 04:54 AM:

Check that your switches aren't sticking or faulty. [Wink]

Posted by John Wilson (Member # 269) on 01-14-2004, 06:42 AM:

Hi Matt

Have you checked the rubber stopper like I suggested? I'd be interested to know how you got on with your problem.

John

Posted by Matt Frankish (Member # 2131) on 01-14-2004, 03:58 PM:

Thanks folks,

I can't say i was expecting someone who's actually ran the projector in question to pop up! I don't think we've ever actually met, Stephen - you've probably only ever seen Steve Wilsher. Yes, it is the same problem that we've had for a while although it's become much worse recently. At the end of the film we've been getting a fair bit of leader on the curtains!

I'm told by Steve that they are 1.6ks but we underrun them. It definately a 2k Lamphouse.

Apologies for the lateness in replying - I've been waiting to see whether the fix was permanent or temporary, but it seems to be permanent. I also keep getting stung by your "Bookmarking Not Allowed" function which seems to disagree with my use of the back button. I can't find any settings for HTTP_Referer anywhere, so if anyone has an idea what I'm doing wrong, drop me an e-mail. matt_frankish@croydon.gov.uk. I'm running Mac OSX.2.8 and Safari 1.0.1

Anyway, back on-topic:

We took the gate cover off and had a poke about inside. The stopper is actually made of brass or a similar metal and didn't seem damaged in any way. So, we opened the other one (that works fine) and did a compare and contrast. After a bit of back and forth-ing it seems that the spring that closes the shutter was fitted slightly differently on the two mechanisms. We put a lot more tension on the dodgy one and it seems to have done the trick! There is some bounce, but it isn't visible onscreen.

So thank you all. It seems our problem is dealt with.

Posted by Daryl C. W. O'Shea (Member # 1303) on 01-14-2004, 04:24 PM:

Safari is evil. Its javascipt engine is flawed.

Solution: Don't use the back button.

Posted by Steve Guttag (Member # 268) on 01-14-2004, 06:56 PM:

Now since I got the spring part right...trust me you can eliminate the bounce too!

There is a damper to stop the douser from bouncing. To get it adjusted I recommend removing the douser from the projector. The plunger on the damper should hit the stop block squarely. Then adjusting the damper itself (screwing it in and out) you can get it to stop the douser with a nice "thud." However, when adjusting it it...you want to let the spring do the closing and to hold the assembly exactly as it is held in the projector...there will be a sweet spot where it will work like it is supposed to and not really drift.

Steve