Airbearing tonearm design (not Ladegaard)

[koyaanisqatsi]

i've been reading the Ladegaard tonearm threads and have come up with a new airbearing design (henceforth know as the koyaanisqatsi-airbearing-tonearm (lol).

the first airbearing tonearm: Post #39

a diy Ladengraad design: Post #58

basically i want to float a solid balsawood cylinder on a semi-circular concave rail, with a ebony armtube passing through its' central axis. air will be supplied by a giant seringe with a weight on top to fine tune and regulate airpressure; similar to the old coal gas storage tanks (but not so big i hope!), to refill the cylinder i'll take the weight off ,open a valve and pull the cylinder back up by hand; sucking air in.

1.keeping unnecassary weight to a minimum (whilst using the most suitable material for the armtube; hardwood).

2.balsawood will insulate the arm from air supply noise (the rush of air)

3.eliminate ringing by not using any metal on the tonearm (only in the counterweight: which will be something like Jeffs' counterweight: http://www.william-reed.net/audio/newpics/ )

4.eliminate air pump noise- no pump

5.the centre of gravity and the turning axis will be as close together as any normal tonearm: eliminating the need for an underslung counterweight.

does anyone have any thought or suggestions?

thanks
steve

[koyaanisqatsi]

the first airbearing tonearm: Post #39
a diy Ladegaard : Post #58

hope this works this time

[bulgin]

Hi koyaanisqatsi

I'm not trying to be funny and I admire your armbuilding initiative but what is a 'solid cylinder'? I thought (maybe incorrectly), a cylinder is a hollow tube which can't be 'solid' by it's very nature. Is it a thickwall tube or just a plain roundbar?

Regards

bulgin

[koyaanisqatsi]

just a plain solid roundbar (about an inch in diameter)

[koyaanisqatsi]

http://www.specializedbalsa.com/dowels.php

[bulgin]

Hi koyaanisqatsi

Thanks for the link! I also rcently finished 'half an arm' - a conversion to a j-shaped wand for one of my Micro arms which had a straight graphite wand before. I made the wand from a r/c helicopter landing sled and the front end is now fitted with an sme socket. The reason? I ran out of Micro headshells. Sounds and looks great, but a very fiffly job.

bulgin

[bulgin]

Darn! these old rheumatoid digits..."fiddly" I meant to write.

bulgin

[Dumbass]

I wish you best of luck but am very skeptical about your alternative to the air pump.

This is after spending a bit of time working on a Laadegaard arm. It was very difficult for me to get the trough working without a rather large aquarium pump. I tabled the project indefinitely.

Keep us apprised of your progress.

[sreten]

Originally posted by bulgin
Hi koyaanisqatsi

I'm not trying to be funny and I admire your armbuilding initiative but what is a 'solid cylinder'? I thought (maybe incorrectly), a cylinder is a hollow tube which can't be 'solid' by it's very nature. Is it a thickwall tube or just a plain roundbar?

Regards

bulgin

Hi,

By default a sphere, cube, cylinder etc are solid, unless you are referring to the surface.
If you are referring to the surface shape, you do need to specify a thickness.

/sreten.

Originally posted by Dumbass
I wish you best of luck but am very skeptical about your alternative to the air pump.

This is after spending a bit of time working on a Laadegaard arm. It was very difficult for me to get the trough working without a rather large aquarium pump. I tabled the project indefinitely.

Keep us apprised of your progress.

Hi,

I agree, but it could form the basis of a pressure regulator for
the air pump.

/sreten.

[livemusic]

Hi Steve,
I wish you good luck with your project: I like simple real stuff better than any sofisticated discussion.
Practically speaking, I do not think your air supply will be capable to provide required air flow for any considerable time. Once I was fascinated with the idea of using scuba tank as an air source. But, after doing math, I saw that the standard scuba tank of 77 liter/3000 psi will last about 12 hours maximum: you will hardly want to refill it every 3-4 days. Do your math first!
Cheers,
michael