The 3 types of drives:
The O-drive: the tape is turned around the head drum counter clockwise from about 6 to 9 o’clock. This is the oldest and most complicated solution of a 8mm drive. Originally it was developed for professional applications. In the “EV-O” series of professional VCR’s it was indeed marketed up to the mid 90’s. Contrary to this in the “EV-S” series of amateur VCR’s the O-drive was replaced in 1990 by the U-drive starting with the EV-S550. Technically the O-drive was equipped with up to 5 servo motors, from loading the cassette, the playback or fast wind functions. A state of the art planet gear drive composed of brass and plastic is integrated in the main drive functions. Another characteristic is a wide rink of sprockets onto which the rubber wheel and several tape guides are mounted. During loading of the tape this rink is turned in the afore mentioned counterclockwise direction at about 340° around the haed drum. Because of this circle-like motion this type of drive is named the “O”-drive. Due to this construction the O-drive shows comparatively high reliability. It is, however, somewhat slow, when changing to another function of the drive ans especially when changing a cassette.
Compared with this, the U-drive is a fast cassette loader. During this, two guides will lead the tape from the two lower opposite sides around the head drum. During this the two guides mark an “U”. During fast winding operations, this drive, however, is comparatively slow. The propelling of which is done by a synchro motor and sprocket belt, activating a sprocket wheel and the tape reel. The rewind time for a 90Min. cassette is 4Min.. Actually this drive was engineered for the new series of “F”-camcorders, which explains, why it is comparatively slow as well as light weighted.
The F-drive is a redesign of the U-drive. Similar to this, it has two tape guides. Additionally these guides may stop at a medium position, so that the tape just does not hit the drum. Together with the wound tape they form an “F”. In this position a very fast rewind of a 90Min. cassette is enabled in just 1Min.. Tape and video heads thus are well protected. Also, some other weak points of the U-drive were redesigned, such as the solid base of the drive, a very solid capstan, a less complicated and stabilized cassette intake, solid washers and counter screws under the 2 tape guides.