Has anybody else seen this series of videos?

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Here's the website: http://kiirojbl.exblog.jp/i109

He uses a linear motion bushing LM4 from THK:

https://tech.thk.com/en/products/thk_cat_main.php?id=322

Pretty neat! I think the mass can be reduced even further. In the video's comments he says he needed to polish the rod to mirror surface for it to work well.

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http://kiirojbl.exblog.jp/i109

An interesting post, thanks. , posted on April 21, 2010 at 11:43:46

beach cruiser
Audiophile

Posts: 7061
Location: so cal
Joined: September 24, 2003

While I favor a more low friction approach, I support the guys fun.

I would want to blow a supply of air into that moving joint, to avoid all of that contact surface.
But them I would have the drag of the air line. Hmmm.

Perhaps a liquid cushion, instead of air, with the oil dropped from above, without connection, into a small funnel shape on top of a total loss oiling system. Or perhaps damping fluid would lubricate well enough as it flowed through the workings to get the friction down to normal pivoted arm levels.

I wonder how strong the cart has to be move past all the friction in the pictured design, and still report accurately. In the video it seems to grab a little as the angle is increased to return the arm to the rest. ( Yes, I see this is outside of the normal operating angle)

RE: DIY tonearm using linear motion bushing, posted on April 21, 2010 at 11:53:21
jihad Audiophile Posts: 2342 Location: chain o' lakes Joined: February 20, 2003	I found that a few weeks ago. The translations on his site leave alot to desire. I'm not hip on the multiple postings, thanks for posting it. I find this guys DIY work just incredible. Never attribute to malice that which can be adequately explained by stupidity.

more linear tracking arms sans air bearing, posted on April 21, 2010 at 12:24:35

caligari
Audiophile

Posts: 415
Joined: March 20, 2008

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Instead of DIY, here's a mechanical linear tracking arm from Clearaudio in their obscenely expensive Statement turntable, the TT1 tonarm. It uses two ball bearings gliding laterally across a glass tube, very similar to Opus3 Cantus tonearm and probably inspired by it.

I am not a fan of air pumps so I want to look for alternatives. It's more fun to come up with ideas using mechanical means. I think using levitating magnets will work too.

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RE: more linear tracking arms sans air bearing, posted on April 21, 2010 at 13:36:27
caligari Audiophile Posts: 415 Joined: March 20, 2008	. Different versions of Nottingham Paragon linear tracker. Again, only two V-groove ball bearings on a slider. . . .

Vinyl Asylum

Has anybody else seen this series of videos?

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