The Talking Machine Forum — For All Antique Phonographs & Recordings

I’ve dismantled it now, and can see how it should fit together so there is no vertical movement. You can see down into the tone arm, there is a small plate has been welded on, and the pointed end of the shaft sits in that, with the brass nut in such a position that it comes through the hole in the middle once the two pieces are connected. The other nut then goes on to keep it all in place. I cannot tighten that too much though otherwise it will impede the lateral movement of the arm. Do you think it would be an idea to employ a second, locking nut that allows the lateral movement but stops it coming loose again? I think there would be room.
I think the cracks that you noticed area trick of the light in my earlier photo. They are shadows rat hare than a crack. As to how much is pot metal - how do I tell?

I'm guessing the small brass piece is threaded to screw onto the post, like a nut? How well does the outside diameter of the brass piece fit in the cross bar of the tone arm? Fairly close? Sloppy?

Yes that’s right, the brass piece is threaded and one end of it is flat-sided so in theory you could hold with a spanner. The other end of it is circular and fits closely inside the circular hole in the cross bar of the tone arm. I shall have a play around, as it’s obviously been designed to fit tightly but to allow lateral movement of the arm (as long as there’s nothing missing).
If I only had a needle screw for the soundbox I’d be able to test it all out!