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Topic: adjusting screw on 3580 series

Jim Schrader
Phenomenal Film Handler

Posts: 1628
From: Savage, MN, USA
Registered: Jun 2003

posted March 30, 2007 08:21 AM

I notice there is an adjusting screw on the Bell & Howell/Eiki models SSL-O on the take up arm the manual states nothing on this can someone shed a light on this I picked up a almost like brand new Eiki SSL-O th eother night for less than 20.00 it looks and runs like a dream but noticed this. thanks for any help

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jim schrader
"Let's see “do I have that title already?"

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John Whittle
Jedi Master Film Handler

Posts: 791
From: Northridge, CA USA
Registered: Jun 2003

posted April 01, 2007 10:03 AM

B. Adjustments
1. Take-Up Torque
The take-up arm belt must be kept clean with the blue side of the belt positioned towards the pulleys. Avoid any oily substances on the belt. Clean the belt with Isoprophyl Alcohol. The take-up tension is adjusted by increasing or decreasing the belt tension with the adjustment screw. This tension should have a range from approximately 90 grams to 160 grams, depending on the reel size. Torque in excess of 150 grams should not be permitted on small film reels Under normal operation where small to medium size reels are used, the tension screw should be adjusted to where it barely makes contact with the tension spring (1mm to 3mm). Clockwise adjustment increases the take-up torque. Counter clockwise adjustment decreases the take-up torque.

From Eiki Service Manual for SSL/ series machines.

John

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Lars Pettersson
Master Film Handler

Posts: 282
From: Stockholm, Sweden
Registered: Jan 2007

posted April 02, 2007 03:30 AM

Hello John!

I posted his question on the 8 mm forum a few days ago hoping you´d see it, would you mind awfully to shed some light onto this, please: I read in the Bauer P8 16mm projector manual "Shutter Relationship 1:6,9". It must have something to do with how long the frame is held and how quickly the next one is pulled down, and I suppose "Engineering Heaven" here would be "very long" in the first case, and "speed-of-light" in the second but SERIOUSLY, what exactly does it mean? Would 1:6,9 be mediocre, so-so or brilliant? I have no idea. I understand the Kinoton electronic projectors pull down film REALLY fast -what kind of value would that mean?

You could answer me at home if you don´t want to clutter up this thread:
la55e (dot) p (at) telia (dot) com

Best Wishes
Lars

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John Whittle
Jedi Master Film Handler

Posts: 791
From: Northridge, CA USA
Registered: Jun 2003

posted April 03, 2007 03:35 PM

Lars,
Since we use a different measure of notation here between commas and periods, I think this is referring to the relationship between dark and light or shutter opening and closing. Is it a two or three blade shutter?
Here we'd talk about the number of degrees of the blade (or dark cycle) of the shutter vs the open which cuold be expressed in your relations ship of 1:6,9 or about 1:7. If you had a 2 blade shutter with 30 degree blades than 60 degrees would be dark out of 360 or 1:6 so it would seem that the blades are just slightly larger than 30 degrees and would be set by the pull down cam to make sure that the frame had settled in the gate before the blade opened.

For fun, in the olden days, there were projectors with both front and rear shutters. The effect is a dissolving as the image is inverted by the lens and one blade cuts from the top and the other from the bottom.

The same effect can be had with a barrel shutter which was used in JAN projectors and the Ampro series. They take up much less space but require additional gearing and timing to get them right.

John

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Lars Pettersson
Master Film Handler

Posts: 282
From: Stockholm, Sweden
Registered: Jan 2007

posted April 04, 2007 01:33 AM

Hello John!

Here are all the specs from the Bauer P8 16mm projector manual: 2-bladed shutter, 70 degrees. "Shutter Relationship 1:6,9". This would mean 2 * 70 degrees dark + 2 * 110 degrees light = 360 degrees (?) But I still don´t quite get the 1:6,9 part [Embarrassed]

70 degrees dark would mean fairly "slow" pulldown, wouldn´t you say?
Could you please elaborate a little bit on how long the frame is held and how quickly the next one is pulled down, as the ideal here would be "very long" in the first case, and "very fast" in the second. I understand the Kinoton electronic projectors pull down film REALLY fast -what are the pros and cons?

You could answer me at home if you don´t want to clutter up this thread:
la55e (dot) p (at) telia (dot) com

Best Wishes
Lars

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John Whittle
Jedi Master Film Handler

Posts: 791
From: Northridge, CA USA
Registered: Jun 2003

posted April 04, 2007 08:34 AM

I don't quite get the 1:6,9 either. But remember the shutter dark period isn't just to cover the pull down, the impluses have to be ballanced so you don't induce flicker. The more even the dark/light intervals, the less the chance for flicker and as you know it gets worse with an increase in screen brightness from either a highler lamp (xenon) or bright scene.

Pull down isn't just a matter of quickness, you have to consider the stress placed on the film from acceleration and stopping and the friction necessary to stop the film when the claw is retracted. The faster the pull down, the more wear on the sprocket. That's why the electronic advance system can be quicker since a full fitted sprocket wheel is usually employed to move and stop the film.

Another method used air to blow the film down over a registration pin and then lift and reset it. A very costly and fine tuned system used in an early Kinescope camera in the 1950s and on an optical reduction printer in the 1970s.

John

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Jim Schrader
Phenomenal Film Handler

Posts: 1628
From: Savage, MN, USA
Registered: Jun 2003

posted April 06, 2007 06:52 AM

thanks for that info John I will check it out [Smile]

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jim schrader
"Let's see “do I have that title already?"

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