Understanding 45 RPM Records and Their Fat Spindles
45 RPM records, a format that became ubiquitous in the mid-20th century, were designed with specific features to cater to the needs of both home users and commercial establishments. One of these key features is the 'fat' spindle or wide hole at the center of the record.
The Purpose of the Fat Spindle
The wide hole in a 45 RPM record spindle serves multiple purposes. One of the primary reasons for this design is the convenience of stacking multiple 45s. At home, playtime was often limited to just two minutes, allowing users to stack a half-dozen or more 45s to enjoy music for a longer period without frequent interruptions. This setup was perfect for jukeboxes and automatic turntables, where a player could cue up several 45s, “dance for 15 minutes or so,” and then carry the records to the storage slots. The wide hole ensured that the stack was more stable, reducing the risk of the records slipping.
Improved Stability and Mechanisms
In jukeboxes, the wide spindle hole was large enough for a mechanical arm to fit inside. This arm had little grippers that held the records and carried them to the playing position. After the record finished playing, it returned to its storage slot in a similarly controlled manner. This design was crucial for the smooth and efficient operation of jukeboxes and automatic turntables.
Different Record Spindle Designs
Not all record players used the same spindle design. Some models had a slender spindle that was a legacy of 78 RPM records. This spindle could be placed into a depression and then locked into place with a slight twist. Other turntables had a specialized setup for 7-inch (45 RPM) and 12-inch (LP) records. A wider spindle would fit in a depression at the height of the outer rim, supporting the LP and ensuring proper alignment.
Usage in Radio Stations and Home Playbacks
During the mid-century, the use of 45 RPM records extended beyond homes and jukeboxes into commercial settings. In radio stations, a rotary fader allowed DJs to cue up records while monitoring sounds through headphones. DJs used special styli that were strong enough to turn the record backwards if needed, and felt pads on the platter helped them to identify the start point of a record.
In a small station I worked at, the AM station operated during daytime hours, while the FM station broadcast from six AM until midnight. Due to FCC regulations, the stations couldn't simulcast, forcing them to play different content. From 1 PM to 6 PM, LP records were used to fill the airwaves with news and station IDs. However, this stack of records occasionally caused issues; employees received calls when a record started skipping, often due to the smaller spindle on LPs.
Special Cases and Innovations
Some jukeboxes played both 78 RPM and 45 RPM records. The wide hole design of the 45 RPM records made the mechanisms simpler and more cost-effective. Home players could use a fat adapter to fit the wide hole, or the provided plastic inserts. This versatility allowed for the inclusion of 45s in the jukebox.
Specialty 45s could also be manufactured with a central plug for a smaller spindle. However, these records would not sit flat on the turntables of some models, such as QRK's. These turntables often had a mechanical selector for different capstan sections, a spring-loaded idler wheel, and a toggle switch to operate the motor.
Conclusion
The wide hole design in 45 RPM records was not merely a technical necessity but a strategic move by the industry to cater to a new segment of consumers. It allowed for easier handling and stacking, making 45s popular among young consumers who could easily purchase and play their favorite singles. Despite technological advancements, the wide spindle hole continues to be an important design feature in modern records, ensuring both durability and ease of use.