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With regard to a thread of six years ago, https://8mmforum.film-tech.com/cgi-b...=011186#000000, I’d like to bring a short contribution I have just recently published on a German forum, translated by myself. Please allow my swiss-german English
Filmers want adjustable speed, a bright, sharp image, quiet functioning, an inexpensive lamp and the ability to put on at least 120 meters of film. Kodak?
The early Kodascopes Eight were created to spread the new, affordable film format. They certainly had their merits but they looked older with every competing projector that came onto the market. After a few years of Double-Eight Rochester had to realize that a better model was needed. In the fall of 1939 EKC began advertising a de luxe 8-mm. projector.
I want to discuss the Seventy briefly, without pictures, so that we can later refer to the information we have collected. A statement I’ve read somewhere is uncertain, namely that the projector was manufactured for Eastman-Kodak, not by. It’s also been said that it was made in 1937-38, which can well be true. The instruction manual is dated August 1939, sales began, as far as I can tell, in November of 1939.
The important features
What is most noticeable is the departure from the circular eccentric in the claw drive. The vertical claw movement is accomplished by a cam on an additional shaft. This is geared to the main shaft in the ratio of 1:2. On the main shaft there is a control disc for the movement back and forth. The claw arm thus performs an idle stroke. The cam rotates through about 120 degrees to transport the film, while a shutter blade covers the aperture.
The three-blades shutter has 62 degrees openings between 58 degrees blades which corresponds to the light-dark ratio of 1.07:1. The first Kodascopes Eight have an even lower ratio of less than 1:1 meaning that half of the lamp energy (light and heat) is burnt off on the shutter.
The vertical image position is adjusted by screwing the claw arm up and down against a round wire spring. The aperture of the specimen I examined has the dimensions 3,27 mm by 4,37 mm. The register distance is +4/5. The projector does run backwards but there is a contraption that prevents us from feeding the film through the gate backwards. We are supposed to only rewind by motor.
A 10-inch long V-belt transfers energy from the motor to the mechanism.
Concerning general construction there is to say: light metal alloy die-cast housing with pressed-in threaded steel bushings for screws. This sets the Seventy apart from many devices. The possibility to oil the mechanism is also a good thing, notably via felt strips to the claw assembly. But not all bearings are included. Self-lubricating bearings were proudly pointed out, since long dry today. However, we can remove the cover on the mechanism and lubricate that. The motor bearings cannot be reached.
The fan wheel is made of steel. A cardboard disc is riveted in between it and the motor. It seems to me that it could be removed to achieve better cooling of the motor.
The condenser can be pulled out upwards after removing the lamp house. We can also get to the concave mirror. A non-bloomed one-inch four elements lens, f/1.6, two cemented achromat doublets, was included, barrel diameter 23 mm. The price of the projector was $59.50, $1328.35 today, without a lamp! One used 300, 400 or 500 Watt lamps, the latter of which would cost $103 today.
Nothing de luxe. Mechanics very solid. Light efficiency at the lowest level. Not interesting due to the limitation to 60 meter reels. The only difference of the model 70A is that it has spool arms for 120 meters. Better.
A friction governor device switches on heat protectors when speed falls below a preset value. No still image projection. The fixation to the base is too primitive. At least the projector came in a sturdy, protective case.
Filmers want adjustable speed, a bright, sharp image, quiet functioning, an inexpensive lamp and the ability to put on at least 120 meters of film. Kodak?
The early Kodascopes Eight were created to spread the new, affordable film format. They certainly had their merits but they looked older with every competing projector that came onto the market. After a few years of Double-Eight Rochester had to realize that a better model was needed. In the fall of 1939 EKC began advertising a de luxe 8-mm. projector.
I want to discuss the Seventy briefly, without pictures, so that we can later refer to the information we have collected. A statement I’ve read somewhere is uncertain, namely that the projector was manufactured for Eastman-Kodak, not by. It’s also been said that it was made in 1937-38, which can well be true. The instruction manual is dated August 1939, sales began, as far as I can tell, in November of 1939.
The important features
What is most noticeable is the departure from the circular eccentric in the claw drive. The vertical claw movement is accomplished by a cam on an additional shaft. This is geared to the main shaft in the ratio of 1:2. On the main shaft there is a control disc for the movement back and forth. The claw arm thus performs an idle stroke. The cam rotates through about 120 degrees to transport the film, while a shutter blade covers the aperture.
The three-blades shutter has 62 degrees openings between 58 degrees blades which corresponds to the light-dark ratio of 1.07:1. The first Kodascopes Eight have an even lower ratio of less than 1:1 meaning that half of the lamp energy (light and heat) is burnt off on the shutter.
The vertical image position is adjusted by screwing the claw arm up and down against a round wire spring. The aperture of the specimen I examined has the dimensions 3,27 mm by 4,37 mm. The register distance is +4/5. The projector does run backwards but there is a contraption that prevents us from feeding the film through the gate backwards. We are supposed to only rewind by motor.
A 10-inch long V-belt transfers energy from the motor to the mechanism.
Concerning general construction there is to say: light metal alloy die-cast housing with pressed-in threaded steel bushings for screws. This sets the Seventy apart from many devices. The possibility to oil the mechanism is also a good thing, notably via felt strips to the claw assembly. But not all bearings are included. Self-lubricating bearings were proudly pointed out, since long dry today. However, we can remove the cover on the mechanism and lubricate that. The motor bearings cannot be reached.
The fan wheel is made of steel. A cardboard disc is riveted in between it and the motor. It seems to me that it could be removed to achieve better cooling of the motor.
The condenser can be pulled out upwards after removing the lamp house. We can also get to the concave mirror. A non-bloomed one-inch four elements lens, f/1.6, two cemented achromat doublets, was included, barrel diameter 23 mm. The price of the projector was $59.50, $1328.35 today, without a lamp! One used 300, 400 or 500 Watt lamps, the latter of which would cost $103 today.
Nothing de luxe. Mechanics very solid. Light efficiency at the lowest level. Not interesting due to the limitation to 60 meter reels. The only difference of the model 70A is that it has spool arms for 120 meters. Better.
A friction governor device switches on heat protectors when speed falls below a preset value. No still image projection. The fixation to the base is too primitive. At least the projector came in a sturdy, protective case.