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DIY tonearm, the US Patent Office has many tonearm

Before you re-invent another great tonearm, check with the US Patent Office. The famous Graham, linear air bearing , and magnetic damping tonearms are in there. Many of these patents published in the late 70s and 80s. They are expired and available for public use. The principle of tonearm designs are simple but workmanship and tuning are critical. Make use of your tax money. Unipivot tonearm is simple to make, you can come up with your own tonearm balancing schemes. Have fun
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=0&f=S&l=50&TERM1=tonearm&FIELD1=&co1=AND&TERM2=&FIELD2=&d=ptxt
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nghiep's avatar
nghiep OP
79 posts
 
I guest there is not much interest in DIY tonearm. Unipivot tonearms are simple to make, I make some and they sound great. People have more interest in making turntable plinths instead. Check out my analog photos.

http://www.geocities.com/nghiep16/Vinyl/
johnnantais
621 posts
 
Very interesting, Nghiep, how do you make the pivot point for the tonearm? I have read elsewhere that the best material for a DIY tonearm is a carbon-fibre tube for an arrow at $5! I've been toying with either imitating the Well-Tempered design or building a unipivot for a long time. Good post!
nghiep's avatar
nghiep OP
79 posts
 
Johnnantais, I used both arrow and golfshaft depending on the cartridge compliancy. I used a single ball bearing super glued it on at the end of a stick. Then I made a dimple with a drill bit on the arm tube where the pivot point at. The azimuth balance and the counterweight weights keep the arm tube stable on the ball bearing. I also tried the magnetic and string suspension tonearm but it was too hard to align the cartridge and keep it fixed. The Schroder Reference Tonearm used a bigger ball bearing with a magnet in the post to keep the ball bearing from chattering and the string to reduce the friction on the ball bearing. You have to use a cheap cartridge for tonearm prototype because accident happens.
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