The Talking Machine Forum — For All Antique Phonographs & Recordings

I guess I should have posted my question in this section.
I am working on my Columbia Grand Grafonola and discovered that the fiber gear is cracked. I have a new one but it is about 3/64" smaller in diameter. Does anyone know of a supplier for the slightly larger gear? Also, the teeth on the original are flat at the tip and the new one has teeth that come to a point. I have another old gear that is the same size and has the same teeth shape as the old one pictured. I can't use is because it is missing some teeth.

The teeth on the original fiber gear are flat because they are worn. Ron Sitko has replacements. I am almost certain that they are one size. You might want to adjust the governor or the brass spindle gear. I have worked on many a Columbia motor and the governor adjustment seems to do the trick. Let us know how it works.
Harvey Kravitz

Phonofreak wrote:The teeth on the original fiber gear are flat because they are worn. Ron Sitko has replacements. I am almost certain that they are one size. You might want to adjust the governor or the brass spindle gear. I have worked on many a Columbia motor and the governor adjustment seems to do the trick. Let us know how it works.
Harvey Kravitz

From what I can see, there is a distinct difference between the gears: note that the old one has teeth that are fairly symmetrical in profile, with squared off areas between them. The repro has a distinct , ratchet-like buttress to it, with triangular spaces between the teeth.

Bill

There are no governor adjustments on this style of Columbia motor. The bushing hole is centered.
The original gear is slightly larger in outside diameter than the replacements. I have another bad gear like this from a spare chassis and the teeth are the same shape. The tips of the gear are not worn off. I talked with Duane Wyatt and he said that there were a few variations of these gears. Mine, unfortunately, isn't one that is reproduced. I am looking into making my own. I have been experimenting with some high density Teflon. The only thing I need to figure out is the indexing for the teeth. They are about .040" and there are 34 of them. This makes the hobby so much fun.

I believe Delrin has also been used for spiral-bevel gears...

Did the Viva Tonal motors have fiber gears as well? I'm looking at mine and they all seem to be metal