My unipivot tonearm - diyAudio
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 24th March 2006, 06:58 PM   #1
wmincy is offline wmincy  Malaysia
diyAudio Member
 
Join Date: Sep 2003
Location: Italy
Default My unipivot tonearm

Almost for a half year I have been searching for a worth second-hand tonearm, navigating on ebay, on audio market websites... Nothing, or too expensive or too many bidders. So I decided to build one by myself: unipivot, knive-bearing, or ball-bearing? I choosed the first one as my father has the other two types of tonearm.
Oh, it was very hard to design and in the same time to be able to realize it, while you have only lathe and miller machine (not CNC): every idea is good but not always makeable!
Using lathe and miller macchine of my company (after working hour, of course!), I made all the parts.
Here are some photos of my tonearm.
Attached Images
File Type: jpg dscf0020_1.jpg (67.3 KB, 2455 views)
__________________
the fever of DIY HI-FI will NEVER be cured !!!!
  Reply With Quote
Old 24th March 2006, 06:59 PM   #2
wmincy is offline wmincy  Malaysia
diyAudio Member
 
Join Date: Sep 2003
Location: Italy
another photo
Attached Images
File Type: jpg dscf0021_1.jpg (55.2 KB, 2122 views)
__________________
the fever of DIY HI-FI will NEVER be cured !!!!
  Reply With Quote
Old 24th March 2006, 07:00 PM   #3
wmincy is offline wmincy  Malaysia
diyAudio Member
 
Join Date: Sep 2003
Location: Italy
...another photo
Attached Images
File Type: jpg dscf0022_1.jpg (49.2 KB, 2009 views)
__________________
the fever of DIY HI-FI will NEVER be cured !!!!
  Reply With Quote
Old 24th March 2006, 07:04 PM   #4
wmincy is offline wmincy  Malaysia
diyAudio Member
 
Join Date: Sep 2003
Location: Italy
...photo
Attached Images
File Type: jpg dscf0023_1.jpg (41.8 KB, 1926 views)
__________________
the fever of DIY HI-FI will NEVER be cured !!!!
  Reply With Quote
Old 24th March 2006, 07:34 PM   #5
pixpop is offline pixpop  United States
diyAudio Member
 
pixpop's Avatar
 
Join Date: Jan 2005
Location: Los Angeles
Send a message via Skype™ to pixpop
Very nice. Can you describe the arm some more.. what material is it?
  Reply With Quote
Old 24th March 2006, 11:05 PM   #6
Eggzy is offline Eggzy  United Kingdom
diyAudio Member
 
Join Date: Oct 2005
Default coooooooooooool

wow wmincy that is cool!
are you going to polish the alloy bits or keep the brushed effect?


eric
  Reply With Quote
Old 25th March 2006, 02:02 AM   #7
Eggzy is offline Eggzy  United Kingdom
diyAudio Member
 
Join Date: Oct 2005
Default headshell question

...did you use a router bit to cut the elongated slots in the headshell? if so any probs with juddering?


eric
  Reply With Quote
Old 25th March 2006, 10:43 AM   #8
wmincy is offline wmincy  Malaysia
diyAudio Member
 
Join Date: Sep 2003
Location: Italy
Yes Pixpop, this tonearm lenght is set to 12" (the effective lenght is circa 340mm), you can see the numbers in the picture that indicates different parts (without the support and the entire holder block):
1- the first part of the body is in carbon fiber, and it is from a fishing rod spare part. At first I wanted to use arrow as the body, but there is no sizes for this purpose (diameters are too small).
2 - the second part of the body is in steel, hardened and tempered then grinded, well finished.
3 - the screw, or the pivot of this tonearm, has the end sharpened. It had also been hardened to prevent wear, as it supports all the mass of the tonearm.
4 - the 'V' part is in steel. It balances the lateral rotation, as for a unipivot tonearm is a big problem.
5 - two 3mm shaft that connect the counterweight with the V part.
6 - counterweight shaft. In alluminium.
7 - the brass counterweight. Around 200 gram.

The support of the screw was a big problem since the begining of the project. It should be absolutely sharp! Not round ended. This problem brought me to the hardness test machine. It a Vicker's hardness test machine with use of diamond cone. Before heat treating the support, I imprinted the cone form on it, so as result a very sharp and hard cone form!

The headshell is worked with miller machine (router is for wood), this one is in steel, but i'm not very satisfied about this choice. May be later i'll make one of alluminium.
Attached Images
File Type: jpg tonearm_note.jpg (65.8 KB, 1883 views)
__________________
the fever of DIY HI-FI will NEVER be cured !!!!
  Reply With Quote
Old 25th March 2006, 10:54 AM   #9
wmincy is offline wmincy  Malaysia
diyAudio Member
 
Join Date: Sep 2003
Location: Italy
Eric,

polishing is one of the matter that care a lot, but as you have noticed it is still not as reflective as a mirror... Every part has been grinded for hours (the polishing took so much time that i almost became mad!) and sand sprayed. May be a chrome coating should bring it shining!! haha

Or using a render software.... hehe
Attached Images
File Type: jpg tonearm01.jpg (52.5 KB, 1505 views)
__________________
the fever of DIY HI-FI will NEVER be cured !!!!
  Reply With Quote
Old 25th March 2006, 01:55 PM   #10
Eggzy is offline Eggzy  United Kingdom
diyAudio Member
 
Join Date: Oct 2005
Ah! I see WMINCY...
I thought the headshell was aluminium.

The reason I asked is because, I love to polish aluminium myself, I got a metal polishing kit from ebay & you can get a beautiful mirror finish with a little effort! Works with plastic bits too!

POINT OF INTEREST; I've noticed a lot of counterbalances which are de-coupled with rubber grommets etc. I can't help wondering whether this is a good or a bad thing? Could this just be creating an 'energy storage area?'

Has anybody examined the merits or drawbacks of a pivoted [swinging] counterbalance?

Anyway WMINCY its a wonderful arm. Keep up the good work

Eric
  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
DIY Unipivot - ClearTone deltavektor Analogue Source 7 15th October 2008 07:31 AM
Linear tracking tonearm vs. Pivoting tonearm Don Nebel Analogue Source 1 4th November 2007 10:49 PM
More unipivot questions... GhettoSQ Analogue Source 12 26th July 2006 09:19 PM
Frank's diy Unipivot arm is about due ? ktigerb Analogue Source 2 28th July 2003 08:44 AM
DECCA unipivot tonearm Merijn Analogue Source 19 3rd February 2003 11:07 AM


New To Site? Need Help?

All times are GMT. The time now is 09:19 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