Need Help Adjusting the Columbia BK/BKT Four-Minute Adapter
Posted: Mon May 15, 2017 6:35 pm
I am restoring a Columbia BK with a four-minute adapter. I really don’t plan on playing four-minute records on this machine (I don’t have the right reproducer anyway), but I was interested in making the speed adjustment functional because it looks like a very interesting little device.
My question is about the two planet gears which appear to engage with the feed screw gear when you switch the phono to four-minute operation. When I obtained the phonograph these were just dangling loose so I didn’t understand until I began reassembly that you should move the mount which holds the planetary gears until one of them engages properly, then tighten the screw that holds the intermediate gear train.
I see that one of the planet gears extends further than the other. I assume that is the one which should engage with the feed screw gear? Do you play with the mount which holds the two planet gears until you obtain the best engagement with the feed screw? Do you position this mount where it is above the feed screw gear or below it?
I have tried both ways and it seems to be a pretty finicky little mechanism. There doesn’t seem to be much room between being not quite or too tightly engaged. The planetary gears on my adapter may also be a bit worn and not doing as well as they should.
I was just wondering if this little adapter is supposed to be this finicky or if mine is just half worn out.
Steve
My question is about the two planet gears which appear to engage with the feed screw gear when you switch the phono to four-minute operation. When I obtained the phonograph these were just dangling loose so I didn’t understand until I began reassembly that you should move the mount which holds the planetary gears until one of them engages properly, then tighten the screw that holds the intermediate gear train.
I see that one of the planet gears extends further than the other. I assume that is the one which should engage with the feed screw gear? Do you play with the mount which holds the two planet gears until you obtain the best engagement with the feed screw? Do you position this mount where it is above the feed screw gear or below it?
I have tried both ways and it seems to be a pretty finicky little mechanism. There doesn’t seem to be much room between being not quite or too tightly engaged. The planetary gears on my adapter may also be a bit worn and not doing as well as they should.
I was just wondering if this little adapter is supposed to be this finicky or if mine is just half worn out.
Steve