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Topic: Help Wanted with film path on Cirse Sound
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Allen Nunneley
Junior
Posts: 8
From: Mullion Cove, Cornwall, UK
Registered: Feb 2016
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posted June 25, 2016 08:49 AM
Thank you gentlemen and for the link to the image.
One final problem to solve is motor speed.
The Cirse has two motors, one drives the gate and pulleys at 16 or 24 fps via a stepped pulley.
The other drives the film close to the magnetic head using a pinch wheel, ( as most reel to reel tape recorders ) at 16 to 24 fps with a variable control.
This variable control moves a spindle against a rubber wheel about 4 inches in diameter, moving either near to its spindle or towards the outer edge, like a pick up and its turntable.
The test film has no pictures but has music on its magnetic track.
Running the projector at 16 fps via the stepped pulley and adjusting the variable pinch wheel drive to the same speed by keeping the loop the same size it sounds fine, there is a female voice on one part which sounds about right.
Switching the stepped pulley to 24 fps and adjusting the variable pinch wheel speed and it sound too fast as would be expected.
However last night I ran a western sound film Badmen of Arizona at 24 fps, it was sounding slow, increasing the variable pinch wheel speed would correct it, but the loop soon disappeared and the two drives were competing which slowed it down.
Whether there is supposed to be some connection electronically between the variable speed control and the stepped pulley motor I have not looked into.
Both the motors are fed via separate capacitors, they as far as I have so far looked into not brush motors and are mains frequency driven.
I do not think the stepped motor drive is slipping and I did re-adjust the stepped pulley to make sure it was not touching the side of the step.
It is a strange arrangement, I can not at the moment see why the drives will not get out of step even when I have sorted out the slow sound ?
I have ordered the instruction booklet to see if it shines any light on the subject.
I am still not sure about the correct way to lace it up, the booklet should also sort that one though how any configuration is going to stop two motor playing catch up is beyond me : ) ?
God Bless Allen and Alanna
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John Hunter
Junior
Posts: 30
From: Gretna, Scotland
Registered: Jun 2015
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posted June 25, 2016 09:41 AM
Allen. You say you have ordered the owners book on this projector, and you may already have it, but in case you have not:
the photo Maurice put up is excellent, but the film lace-up is wrong.From the bottom of the film gate, it goes under the first static roller, then over the 2nd static roller into the sound head, lifting the small lug to help the film in. It then goes around the rubber roller and then up and over the next roller, then under the roller on the arm. From there it goes to the sprocket then reel. The idea is that when the film is running, the roller on the arm should be kept in a horizontal position. This should keep the two motors at the same speed. Hope you can understand this Allen.
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j.hunter
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Allen Nunneley
Junior
Posts: 8
From: Mullion Cove, Cornwall, UK
Registered: Feb 2016
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posted June 25, 2016 11:54 AM
Hallo John,
Bang Bang OK Curly this is it ( :
Thank you so much it ran fine, I had tried it like that but did not know the magic bit about keeping the arm horizontal.
Plus the talk over at the start had a guy with a very deep voice which sounded as if it was running slow.
It does not appear to use felt pads to press the magnetic strip against the head like audio recorders do, just two metal pads ?
Can you say if that is correct.
The test film runs fine but there was a bit of squeaking coming from the speaker on the Western as if from the magnetic strip.
The film Badmen of Arizona looked new, no scratches at all.
Reminded me of watching Tex Ritter on a BBC 1 405 line TV in the 1950s, I was always playing cowboys and Indians.
Pity I had already ordered the instruction, booklet never mind my wallet will get over it : )
The pinch wheel is still a little reluctant to start on the stepped pulley despite my efforts, the rubber is a bit hard, I shall have another look at that perhaps more tension in the spring.
It is in amazing condition like new including the cabinet and mike, no mains lead though, I had to make one up with a separate earth wire to a convenient socket directly under the mains plug
God Bless Allen and Alanna
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