How gramophone needles are made.

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emgcr
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How gramophone needles are made.

Post by emgcr »

Here is a very brief but interesting article extracted from "The Meccano Magazine" sometime in 1937 outlining a few of the comtemporary manufacturing methods. Other makers used different techniques, including polishing in drums containing oak shavings which were then tumbled.
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How gramophone needles are made. Meccano Mag' 1937..JPG

gregbogantz
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Re: How gramophone needles are made.

Post by gregbogantz »

Thanks for posting this article. If you click on your photo, it can then be zoomed much larger which allows the text to be read easily. I had always assumed that steel needles were simply cold-formed at the tip and then the mild steel was hardened. I guess there was more than one way they were made.

The Tungstyle needles (similar to the Victor Tungstones) were made just about the way I imagined. But I'm still wondering how they slit the end of the steel shank into which they inserted the tungsten wire which was then staked to hold it in place. The slit had to be only a few thousandths of an inch wide, presumably about 0.007 inch. How do you do that in production? Diamond dust-encrusted saw disc? Curious minds want to know. This is the most difficult part of making one's own tungsten needles - fastening the wire into the shank.
Collecting moss, radios and phonos in the mountains of WNC.

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emgcr
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Re: How gramophone needles are made.

Post by emgcr »

Thank you for your reply. Perhaps this link will help answer some of your questions. As the article says, it is not a job for the amateur !

http://www.hoosierantiquephonographsoci ... -phone.pdf

gregbogantz
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Re: How gramophone needles are made.

Post by gregbogantz »

Thanks for that article describing the Tungstone manufacture. I had heard that Mark Ginter had written something about this topic, but I never found the article.

I still am wondering how they cut the slit into the end of the steel shank that accepts the tungsten wire. Ginter theorizes that it could have been "forged" into the shank, but I doubt it. The slit is VERY small at about 0.010 inch or thereabouts, and probably 30 or 40 thousandths deep. How would you mash this into the end of a piece of even mild steel with tooling that was only ten thousands of an inch wide? Likewise, where do you find a saw with a ten thousandths inch wide blade that can saw a relatively deep slit thru steel? And your saw tool would have to be sufficiently robust that it could withstand numerous uses as would be required in the automated production of these needles without requiring frequent downtime to change the worn out tool. Seems like a formidable task to me.
Collecting moss, radios and phonos in the mountains of WNC.

phonoman-antique
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Re: How gramophone needles are made.

Post by phonoman-antique »

My guess would be a diamond saw blade.
One cheapo dremel type diamond point I used to round off 2000 corners
in mild steel sheet 1/16 inch thickness.
I could not believe the amount of cutting this diamond point did.
The diamond point set cost $2.50 for a pack of 20 different types.

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