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
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.
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!
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.
Dear Nghiep,
Sorry for kicking in here but your previous post stated that my arms use some form of ball bearing. That is not correct. It`s a magnetically stabilized and damped torsion bearing. And yes, a DIY attempt to recreate the bearing, not to mention the armwands, requires quite an effort, otherwise it`ll turn into a frustrating experience. It`s indeed a lot easier to build a decent unipivot arm(and good luck with it!).

Best regards,

Frank Schröder
Dear Frank, I am flattered that you responed to my post. As you can see from this forum, people rather build the box containers for their TT ( the thread should be about Lenco than Home Depot )than building tonearms. As you see from my page, my tonearm uses ball bearing and lateral weights from the counterweight to control the azimuth. The ball bearing friction was too great which reduced the arm's dynamic. Graham and VPI employed this scheme to control azimuth of a rod in a cup unipivot tonearm which is not as stable as the string as in Well Temper and your Reference tonearm. The hanging string is a great idea because it reduces the ball bearing friction and stablizes the azimuth. The string material greatly effects the sound quality. The ball bearing in the cup fixes the arm as tight as gimball bearing tonearm. It's a good/bad thing that vinyl has been around much longer than us and what we just came up seemed like yesterday news. Of course, we can add few twists and get a new pattent. I listened to Gramham 2.2, VPI, Well Temper, Infinity Black Widow, SME series II and III, Tri Plannar and my "new" tonearm. The hanging string tonearm designs are the most musical of all tonearms that I auditioned. Vinyl was my teenager hobby and I just got back for 1 year after 20 years of listening to CD's.