The Talking Machine Forum — For All Antique Phonographs & Recordings

physicist wrote: ↑Sun May 02, 2021 9:56 pm
If you were planning to make more than a few, it would probably be more cost effective to 3d
print a mould and cast the parts. There is a wider range of castable rubbers available.

It seems to me that the simplest way to make such rubbers is to cut a pair of discs with rubber sheets, bore six holes in each, alternating large and small diameters per the original pattern, and superimpose them back-to-back. The opposite sides are mirror-imaged, so it only takes superimposing the large holes over the small holes, and the rubber will be ready for installation. There is not even the need to glue the discs to each other, the compression of the screws will hold the discs together.

It's a bit more complicated than that. There's a perimeter flange as well as a raised center hub to account for.

Henry wrote: ↑Mon May 03, 2021 7:33 am It's a bit more complicated than that. There's a perimeter flange as well as a raised center hub to account for.

You are correct, however neither are essential for the interface to work properly.

physicist wrote: ↑Sun May 02, 2021 9:56 pm

JerryVan wrote: ↑Sun May 02, 2021 7:54 am Wondering if a "rubbery" material can be 3D printed...

The simple answer to this is "yes" but there are limitations in the range of physical properties.
Most 3d printable synthetic rubbers are at the harder end of the range. It therefore depends
upon what sort of rubber is a suitable replacement to go in the soundbox.
If you were planning to make more than a few, it would probably be more cost effective to 3d
print a mould and cast the parts. There is a wider range of castable rubbers available.

Execellent points! Thanks!

I would buy 4 to have on hand.