Film-Tech Forum ARCHIVE: Clamping a Harry Potter print on an IMAX QTRU

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Posted by Brian Michael Weidemann (Member # 2243) on 11-16-2005, 07:57 PM:

I finished assembling the IMAX DMR print of HP4 today and it is over 153 minutes of footage (46 reels) on the 72-inch "150 minute" platter, the largest print I've personally ever worked with. Of course, there's plenty of room on the platter to hold the film. But clamping it, and safely, is the issue when the radius of the film is only an inch-and-a-half shorter than the platter.

The standard clamps have two pegs each, but the film covers all but the last hole in the platter, so the clamp ends up having to butt out. They clear the bolts protruding from the mast no problem, but they DO hit the first roller on the tension arm; which, since the clamps are on the feed platter, is in its full back position, millimeters away from the platter edge.

So, is there a way to safely clamp this thing? I could probably makeshift something to hold the tension arms just far enough away. Or, what I'll probably do, is get out the old makeshift clamps I used to use which I nut/bolt by hand, every show, to the platter. They're a hassle, but they don't butt out.

Any other suggestions?

I'm screening this in about six hours. [Smile]

Posted by Bob Brown (Member # 1205) on 11-16-2005, 08:11 PM:

Brian,
NO..... there is NO way that I know of that would allow you to safely use the standard clamps with a print that close to the edge of the platter. What I have done in the past with the standard clamps, is to remove the adjustment slider, and with my Dremmel tool, open the slot just a little bit, this allowed the bolts from the small screw in clamps to fit into the slot, and using a washer I then could use the standard clamps, when there was not enough room to allow for the pins. Good luck,, just wait, IMAX will now come out with a 160 or 170 min platter.... [Eek!]

Posted by Robert Stawiarski (Member # 1842) on 11-17-2005, 01:56 AM:

Do you have the screw-in clamps? They are smaller and use a 5/16" Allen screw. I have Harry Potter with trailers for The Polar Express and Deep Sea attached to it, and still have plenty of room with 8 of the screw-in clamps and a Velcro collar. Get a cordless drill with the proper bit and it will not take too much time between shows -- just make sure to reduce the torque on the drill.

IMAX also issued 'posts', basically, they are long 5/16" Allen screws with a plastic coating. They take up less space than the screw-in clamps, but I have not used them yet.

Posted by Dick Vaughan (Member # 540) on 11-17-2005, 03:34 AM:

Brian

the screw in clamps came as part of the upgrade kit when the QTRU has the longer arms fitted to accomodate the 150 min 72" platters.These should be there along with the velcro belly bands.

I will e-mail you direct with the pdf file regarding use of the clamps .

Have a word with your SPP tech (Dave?)who should be able to sort you out

Posted by Brian Michael Weidemann (Member # 2243) on 11-17-2005, 08:10 AM:

Thanks! I did, however, manage to unearth the box containing the screw-in clamps earlier tonight when I remembered setting them aside long ago. It was on a whim that I thought they might help, but it turns out they were designed with my problem in mind. So now I feel foolish. [Embarrassed]

My makeshift nut/bolt clamps worked for our screening, but I noticed they would not work again ... the clearance on the underside of the platter, where the bold heads stuck out, was just too close. Each deck has slight differences.

Anyway, I set aside a 5/16 Allen and we're all set and good to go!