Go Back   Home > Forums > Source & Line > Analogue Source

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

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 14th June 2012, 12:07 AM   #111
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
Hi Ralf,
Looking forward to reading about and seeing all of the updates to your arm project!
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote
Old 14th June 2012, 12:20 AM   #112
lowpoke is offline lowpoke  Australia
diyAudio Member
 
Join Date: Mar 2009
Location: Australia
Send a message via Skype™ to lowpoke
Quote:
Originally Posted by kevinkr View Post
Hi Ralf,
Looking forward to reading about and seeing all of the updates to your arm project!
Me too!!!!!
__________________
Show us what ya got at Homebuilt Hi-fi
  Reply With Quote
Old 14th June 2012, 12:33 AM   #113
von Ah is offline von Ah  United States
diyAudio Member
 
von Ah's Avatar
 
Join Date: Feb 2008
Location: Maryland, USA
Giggity giggity!
  Reply With Quote
Old 14th June 2012, 01:52 AM   #114
diyAudio Member
 
directdriver's Avatar
 
Join Date: Nov 2005
Quote:
Originally Posted by Straight Tracker View Post
I'll write a description of the drastic changes I've made to my Tone Arm and post a few new pictures too.
Can't wait!!
  Reply With Quote
Old 14th June 2012, 03:53 AM   #115
Illusus is offline Illusus  Canada
diyAudio Member
 
Illusus's Avatar
 
Join Date: Sep 2002
Location: Prairie Wasteland, Canada
RE: carbon fiber tubing ringing. Easton makes an aluminium tube with a carbon fibre jacket for use in archery arrows. Carbon fiber and epoxy resin bonded to 7075 core. Very stiff and straight, tolerances (reported by Easton) are .002" over 28" span. I have a few feet of this tubing to play with. It is 5/16" od with very thin walls and when tapped it sounds like it has a very high resonant frequency with very short decay, much better than the thicker walled larger diameter carbon only tubing I compared it to. Nothing measured, just by ear... FWIW.
__________________
Fighting the program since 1976.
  Reply With Quote
Old 2nd April 2013, 12:23 AM   #116
diyAudio Member
 
Join Date: Dec 2006
Is the tonearm finished?
  Reply With Quote
Old 2nd April 2013, 08:07 AM   #117
Cobra2 is offline Cobra2  Norway
DIY !
diyAudio Member
 
Cobra2's Avatar
 
Join Date: Apr 2002
Location: Stavanger, Norway
Send a message via Skype™ to Cobra2
Why carbon-fibre at all? ULM-arms was the hot thing in early 80's, but mass is not an issue?

Arne K
__________________
Don't believe everything you think...
  Reply With Quote
Old 3rd April 2013, 07:42 AM   #118
diyAudio Member
 
Join Date: Nov 2010
Location: Prescott, Arizona
Default Hello everyone,

I find it hard to believe that I havenít posted since June 2012.
You may remember that the object of my tone arm was to utilize vinyl / stylus friction to pull the tone arm carriage along its tracks.
Sometime after June 2012 I got the tone arm to the point where it would play an LP. It has been pointed out by some readers of this thread, Frank Schroeder not being the least of them, that friction would not be constant across the LP and sure enough, the tone arm would not track at true tangency. There was a fraction of a degree of ďlead or lagĒ depending upon modulation. The tracking error wasnít much less than that of a pivoted tone arm.

Since my aim was perfect tangential tracking, I went back to the drawing board (CAD) and redesigned the tone arm until I found another solution. I kept the design of the carriage and the other mechanical features located in the base of the tone arm because it functioned quite well. I changed the design of the gimbals from a ďCĒ shaped design to a closed cylindrical design which is much sturdier and easier to hold onto during machining. But now I have a dilemma: I made a design change to the tone arm that I have to keep to myself for the time being. Patent law is such, that if I make it public in this thread, I lose all rights to the invention. Hopefully I can resolve that problem later this year. The invention applies not only to my tone arm but to tone arms in general. I donít want the big boys to take it away from me. I built two prototype tone arms since June 2012, one of which is mounted on my Micro Seiki turn table. As of now I have not found anyone to design the servo for me and I listen to music by manually nudging the tone arm carriage along its tracks with my thumb. Even though it is a fairly clumsy method, I am delighted to report that it doesnít affect the quality of reproduction.

I have always treated my albums with great care and I can now enjoy the almost flawless playback through my modest system. I can only sit down and listen for about 30 seconds before I have to get up and correct the carriage position but Iíll solve the servo problem sometime this year. In the meantime itís good exercise.

Here are some pictures:

1) My Bridgeport milling machine with which I made most of the parts.
2) My Micro Seiki turn table being machined to accept the tone armís DIN connector.
3) A close-up of the above. Note the lead chip from the layer of sheet lead in the base.
4) The tone arm overall. (minus head shell)
5) The tone arm base and carriage.
6) As above.

Since the pictures were taken, I properly located the tone arm wires inside the left tone arm tube.
Iíll post more pictures soon.

Sincerely,

Ralf
Attached Images
File Type: jpg MY BRIDGEPORT.jpg (970.0 KB, 194 views)
File Type: jpg PA180010.jpg (945.5 KB, 188 views)
File Type: jpg PA180006.jpg (964.3 KB, 177 views)
File Type: jpg TONE ARM OVERALL CROPPED.jpg (662.9 KB, 183 views)
File Type: jpg TONE ARM BASE 1.jpg (972.6 KB, 182 views)
File Type: jpg TONE ARM BASE 2.jpg (968.2 KB, 128 views)
  Reply With Quote
Old 6th April 2013, 12:39 PM   #119
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
Very good work.... thank you for sharing

What kind of servo do you need ?

Mechanical servo, electronic ? How do you feed the servo ?
__________________
RC
  Reply With Quote
Old 7th April 2013, 07:22 AM   #120
diyAudio Member
 
Join Date: Nov 2010
Location: Prescott, Arizona
Default Hello RCruz,

Thank you for your comments.

I need a microcontroller based electromechanical servo.
I am attaching a block diagram of the planned servo.
The microcontroller should provide the various stepping motor frequencies needed for tracking the groove and for traversing the tonearm accross the LP. I have a list of the frequencies needed.

I know enough about electronics to know what I need but not enough to design the circuit myself. I know how to prototype it and build it once I have a circuit diagram.

It is my intention to custom make the tonearm or interest a manufacturer in marketing it.

Sincerely,

Ralf
Attached Files
File Type: pdf TONE_ARM_SERVO_BLOCK_DIAGRAM_NONDISCLOSURE.pdf (26.4 KB, 51 views)

Last edited by Straight Tracker; 7th April 2013 at 07:35 AM. Reason: Rotate PDF
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Tangential Arm Floating Magnets ebijma Analogue Source 8 6th December 2004 06:37 PM
MG-1 AIR BEARING Tangential Arm audio-kraut Analogue Source 7 24th November 2004 07:55 PM
Airpumpless Ladegaard Tangential Arm sreten Analogue Source 31 23rd April 2004 10:58 AM
Turntable physics questions-velocity of tangential arm? perfusionist Analogue Source 66 28th December 2003 04:35 PM
Need tone arm help woody Analogue Source 4 18th June 2003 12:21 AM


New To Site? Need Help?

All times are GMT. The time now is 04:33 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2