The Talking Machine Forum — For All Antique Phonographs & Recordings

I’m looking into buying a Colombia grafonola 112a and I noticed that the sound box no 9 has a round hole chuck which won’t hold my needles. Does the Colombia grafonola 112a soundbox only have a round hole chuck to put needles in? How do the needles stay secured in a round holed chuck as opposed to a triangular hole?

If the needle retaining thumbscrew is operating freely it should screw in far enough to hold the needle firmly in place.
To check it, remove the soundbox and the thumbscrew. Lightly oil the threads and (without a needle) refit the thumbscrew and turn it inwards. You should be able to see the threaded end move across the hole.

The triangular holes found on some soundboxes enabled the use of fibre needles.

Artiebressan wrote: Sat Jun 18, 2022 11:27 pm I’m looking into buying a Colombia grafonola 112a and I noticed that the sound box no 9 has a round hole chuck which won’t hold my needles. Does the Colombia grafonola 112a soundbox only have a round hole chuck to put needles in? How do the needles stay secured in a round holed chuck as opposed to a triangular hole?

Why won't a round hole chuck hold your needles, and what needles are you using, please?

Barry

Normally you should be able to fix any
Standard round needle, only probably too thin needles (those extra-soft or alike) should be difficult to be held in place... If everything is ok, of course.

Some soundboxes won't hold extra soft needles due to the flat end of the screw coming into contact with the round needle hole, thus leaving a semi-circular gap. Take the screw out and file the end to a point. That will cure the problem.

Barry

A point wouldn't solve the problem if too thin. Best way its to examine how the screw arrives to the opposite end when fully screwed in, and figure out what size of chamfer must be ground at the screw end to allow it arrive more deeply into the chuck, still keeping a flat end to press the needle....