Columbia Fiber Gear

[Phono-Phan]

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.

[Phonofreak]

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

[Lucius1958]

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

[Phono-Phan]

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.

[De Soto Frank]

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

[Oceangoer1]

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