8mm Forum: Picture projected off-centre

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Posted by Will Trenfield (Member # 5321) on July 24, 2018, 05:51 PM:

I recently repaired a faulty projector which didn't seem to have been used for over 25 years. I'm sure it's an early forerunner of the Sankyo Dualux 1000 machines but Standard 8 only. A toothed sprocket wheel leads the film through the gate when the threading lever is pressed down but the film has to be threaded onto the take up spool by hand. It runs fine now and projects a sharp, steady picture but...at times, the film is projected off-centre, with the edge of the film opposite the sprocket holes showing on screen together with a band of light from the lamp. The opposite side of the film frame isn't visible. The pressure plate seems to be making good contact with the film in the gate and I can't think what could cause this. Last night, I watched a compilation of 50' family films spliced together on a 200' reel. The first film projected off-centre but after the first splice the rest of the film projected normally. I ran the same reel on another projector (a Sankyo Dualux 1000) without any problem. Any thoughts, please?

Posted by Nantawat Kittiwarakul (Member # 6050) on July 25, 2018, 08:53 PM:

The film seems to slip-off the gate at the first reel,and somehow slip back to the correct position at the splice?

Posted by Will Trenfield (Member # 5321) on July 26, 2018, 05:13 AM:

Yes, that is what happened the other night. The fault has happened at times with other films.

Posted by Maurice Leakey (Member # 916) on July 26, 2018, 09:24 AM:

I suggest that the threading lever isn't returning the gate to its normal closed position after threading.
Also, perhaps the gate springs need replacing, (or you could pull them out slightly.)

Posted by Barry Fritz (Member # 1865) on July 26, 2018, 12:35 PM:

On the side of the gate channel opposite the claw, ther are usually two pressure guides that press against the side edge of the film. With no film in the gate, check these by gently pressing them outward from the channel. They should move out and the return inward when you release pressure. These may need to be cleaned if they do not move out and back smoothly.

Posted by Will Trenfield (Member # 5321) on July 26, 2018, 06:26 PM:

Thanks for the replies all. The pressure guides at the side of the gate channel moved in and out easily. They and the gate have been cleaned using 100% IPA. When the threading lever is pressed, it pulls the top of the pressure plate away from the film channel but the plate goes back once the lever is released. I found what seem to be adjustment screws for the gate springs and tightened them a little. The auto-threading only takes the film through the gate and after that the film needs to be threaded by hand. I think that the threading lever needs to be released immediately the film emerges from the threading mechanism. No handbook, of course. The film which projected off-centre the other night ran perfectly tonight twice. I think between us we cracked it. Cheers!

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