[Arran]

There are more benefits to the large centetr hole on 45s than usually recognised, when used with a single speed 45 changer. Among them are:

1. Simpler change mechanism. No push off or stacking bar mechanism necessary
2. Rapid change cycle
3. All records spin thereby avoiding record skid during change cycle
4. Quieter change cycle
5. Easier to handle records
6. Less center hole wear
7. Inexpensive to manufacture

There are many more advantages when compared with the 78 RPM format it was intended to replace. In that regard, it is a very ingeneous product. The 33 RPM allows an album-length play time, but is too costly for a single play format and fails on many of the other 45 adavntages.

How is a 33-1/3 too costly for singles? If anything they could have used a smaller record then the typical 45 or the same size record with more songs on it, the molds are made the same way. Furthermore why make a 45 record with a 45 RPM rotational speed? It seems to fit in with what I read that they made them with a 45 RPM speed just so RCA could sell 45 RPM players.
Again, with regard to the one inch hole, the only company that made record players with that hole, aside from jukebox manufacturers, was RCA Victor. But RCA quit making them after a time, all of the others used an adapter, but they kept making the 45 RPM records with that silly 1'' hole for a non existant 45 RPM changer right into the 1980s when they quit making them.
Regards
Arran