Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

DIY Air bearing tangent tone arm
DIY Air bearing tangent tone arm
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 20th December 2008, 07:22 PM   #11
livemusic is offline livemusic  Israel
diyAudio Member
 
Join Date: Aug 2002
Location: israel
Here is a diagram showing how the forces and moments applied.
Attached Images
File Type: jpg forces.jpg (43.1 KB, 2590 views)
  Reply With Quote
Old 20th December 2008, 07:27 PM   #12
graeme uk is offline graeme uk  United Kingdom
diyAudio Member
 
Join Date: Dec 2005
Location: essex
Mine doesnt.

Did you build it yourself?

Are the carrier and manifold perfectly matched?

Tried reducing air?

Strange, we get oposite results!

If anything, i think my normal ladegaard arm did this more.
  Reply With Quote
Old 20th December 2008, 08:04 PM   #13
livemusic is offline livemusic  Israel
diyAudio Member
 
Join Date: Aug 2002
Location: israel
This was 5-th incarnation of my arm.
Matching carrier and manifold is easy if you makes them from the very same piece of aluminum angle. Reducing pressure did not reduce rocking but caused carier stucking.
Attached Images
File Type: jpg ladegard 5.jpg (15.6 KB, 2542 views)
  Reply With Quote
Old 20th December 2008, 08:14 PM   #14
graeme uk is offline graeme uk  United Kingdom
diyAudio Member
 
Join Date: Dec 2005
Location: essex
I found using the same piece of angle for carrier and manifold doesnt work as the internal and external angles will be different. The angle is thicker at the corner and thins towards the edge.

When i built my first couple of ladegaard arms i used to get the rocking as the air gap would be thicker at the bottom of the V.

I found there are 2 ways to get a good match, go through all the angle to find 2 that fit together, or lap them together. Lapping will only work if there already pretty much perfect.

If you hold the manifold/carrier up to the light and look at the end, you shouldnt be able to see ANY daylight.

I never managed to get a good match using the same piece of angle, although i know VIC does and his arms are fine.

maybe it depends on who manufactured the angle? Maybe B&Q's stuff isnt that high a quality.

I dunno, but if you get rocking, i bet mismatched angle is to blame, they really do have to be 100% perfect!
  Reply With Quote
Old 22nd December 2008, 11:37 AM   #15
Nanook is offline Nanook  Canada
diyAudio Member
 
Nanook's Avatar
 
Join Date: Feb 2004
Location: Chinook Country.Alberta
Default livemusic...

I am a little confused by your diagram and your explanation.

M:=F Xr , where M is actually torque, a vector . It follows the RHR in vector mathematics. The torque created by a (relatively) large F and a large r could , in fact , move the arm "backwards" if there is enough movement permitted by an imprecise gap between the carrier and the stationary portion of the arm, or the gap is large.

I suspect that graeme uk is on the correct path to answering the "rocking " question.


Maybe my neurons are misfiring across the synaptic gap in my brain, in which case please ignore any comments I make.

stew
__________________
stew -"A sane man in an insane world appears insane."
Let's help Ruth and Dave
  Reply With Quote
Old 22nd December 2008, 07:42 PM   #16
livemusic is offline livemusic  Israel
diyAudio Member
 
Join Date: Aug 2002
Location: israel
Match between slider and manyfold may definitely be improved for any ready made angle profiles; I will try lapping. But anyway, all other factors being the same, the rocking moment is order of magnitude bigger for terminator arm. I have rised a bit a point of contact between the arm knife and slider (two tiny bronze prisms are glued to the slider), such as it lays in the same horizontal plane with the air nozzles placed in the middle of slider bottom surfaces; so the rocking moment is virtually non-existent.
Attached Images
File Type: jpg angle.jpg (21.4 KB, 2303 views)
  Reply With Quote
Old 30th December 2008, 10:47 AM   #17
clivetjm is offline clivetjm  United Kingdom
diyAudio Member
 
Join Date: May 2003
Location: UK
I started out with Vic's conventional Ladergaard and now have the Terminator. The only time I've heard "elephant steps" is with the conventional arm when there was too much air pressure. The Terminator is very insensitive to air pressure levels and works like a dream. It's a significant step up from the conventional Ladegaard type arm that Vic originally produced - which was very good indeed.

If the inverted arm is causing "elephant steps" then there's something wrong but it's either something Vic has got around or never experienced.
  Reply With Quote
Old 31st December 2008, 03:37 AM   #18
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
Quote:
Originally posted by graeme uk
Get the pivot point in the middle of the arm tube, seems to work better.
So the pivot point should be at about 3" & not at the 4" mark as in Vic's terminator pics? In what ways is it better?
  Reply With Quote
Old 4th January 2009, 05:23 PM   #19
graeme uk is offline graeme uk  United Kingdom
diyAudio Member
 
Join Date: Dec 2005
Location: essex
Middle of the arm tube diameter.

My arm tube is about 8cm long from pivot to stylus.
  Reply With Quote
Old 4th January 2009, 07:46 PM   #20
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
Sorry Graeme, I don't understand when you say "middle of the arm tube diameter" - you didn't mean middle of the length of the arm tube then?
  Reply With Quote

Reply


DIY Air bearing tangent tone armHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Looking for Audax bextrene driver for Tangent RS6 dcanuck Multi-Way 4 3rd November 2011 12:30 AM
Tangent's ground channel w/o buffer morfic Solid State 17 2nd August 2009 05:20 AM
Tangent RS4 Speakers - free happyju Multi-Way 0 14th April 2008 04:50 AM
Tangent Monitor 6 upgrade SimontY Multi-Way 8 6th February 2008 11:24 PM
Help with Air Tangent problem arnoldc Analogue Source 3 21st June 2004 06:28 AM


New To Site? Need Help?

All times are GMT. The time now is 12:33 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki