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 linear tonearm
DIY linear tonearm
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 Yesterday, 05:39 PM   #4041
Mike56 is offline Mike56
diyAudio Member
 
Join Date: Apr 2020
Quote:
Originally Posted by nocdplz View Post
Couldn't resist: added the spring (well a rubber band) to work as CW, and behaves the same as previously; and another mock up for the first idea - one lever+2 strings - This one seems easier to build and calibrate, (especially the azimuth). Promising, imo.

Ciao bambo, that mock up "nicely illustrates" simply that the upper rope, under normal tracking conditions is under tension, not compressed.
...there is nothing that prevents the collapse of the whole parallelogram construction:
For sure, exactly as any pivoted without a lifter, but from a lower height. Do you usually put lifters on your mock ups? not me

carlo
always nicer that arm, Mike.
Well, i couldn't resist it either, so out came some aluminium and some Lexan sheet, I filed the notches in the sheet and the points on the aluminium.
the elastic band keeps it together while playing with it.
its roughly the same size as my parallelogram, so i could continue and fit it and you can feel it would work, low friction stable across the plane but i can see it coming to bits and flying all over when setting up etc, i only have one cartridge....and feel it needs always to be firmly attached to something, so for now i will continue to seek out some thinner mylar and see how that way feels. that's an M4 bolt for size
Attached Images
File Type: jpg WIN_20200805_18_29_13_Pro.jpg (881.0 KB, 61 views)
__________________
PC, to Chordette GEM DAC or O.L. Aurora4 with Onyx arm Rega Ania to Graham Slee MC pre, to Prima Luna Prologue 1. Troels Gravesen Fusion BAD with Hypex 151's high level input

Last edited by Mike56; Yesterday at 05:40 PM. Reason: typo
  Reply With Quote
Old Yesterday, 06:22 PM   #4042
grufti is offline grufti  United States
wombat
diyAudio Member
 
grufti's Avatar
 
Join Date: Jun 2004
Location: Hillside
DIY linear tonearm
That looks great. It could possibly be much smaller still. The cartridge shouldn't need more than 4 mm of vertical travel between warps and records of different height.
  Reply With Quote
Old Today, 06:54 AM   #4043
nocdplz is online now nocdplz
diyAudio Member
 
nocdplz's Avatar
 
Join Date: May 2010
Location: italy
Never use a mock up (+ rubber band!) with a real cartridge, even the cheapest in the world!
Mylar: it has to fold with some roundness not on an angle (this will break it), so what about parallelogram geometry?

I've started to think that the inextensible string + one extensible lever (2 small springs to keep it always in touch) may work.

carlo
the cheapest one...
a matter of ethics, not money. The little cartridges, humble companions of our experiments, face a life of sacrifices and dangers with us diyers, too often in absolute silence; sometimes made definitive by our carelessness.
A little respect for their indispensable work, heck

Last edited by nocdplz; Today at 07:17 AM.
  Reply With Quote
Old Today, 07:22 AM   #4044
Mike56 is offline Mike56
diyAudio Member
 
Join Date: Apr 2020
Quote:
Originally Posted by nocdplz View Post
Never use a mock up (+ rubber band!) with a real cartridge, even the cheapest in the world!
Mylar: it has to fold with some roundness not on an angle (this will break it), so what about parallelogram geometry?

I've started to think that the inextensible string + one extensible lever (2 small springs to keep it always in touch) may work.

carlo
I think the Mylar small bend will be very small and consistent on the 4 corners if i can make it very accurately, but time will tell! At the moment i am struggling to buy the very small amount i need!

I also like the idea of some retaining mechanism, but cannot think of one that suits the hand tools only man! Perhaps one solid central lever and inextensible string above and below with tensioning/length setting might work.....this mornings scribble attached, mike
Attached Images
File Type: jpg WIN_20200806_08_19_48_Pro.jpg (367.9 KB, 43 views)
__________________
PC, to Chordette GEM DAC or O.L. Aurora4 with Onyx arm Rega Ania to Graham Slee MC pre, to Prima Luna Prologue 1. Troels Gravesen Fusion BAD with Hypex 151's high level input
  Reply With Quote
Old Today, 08:14 AM   #4045
nocdplz is online now nocdplz
diyAudio Member
 
nocdplz's Avatar
 
Join Date: May 2010
Location: italy
for me better 2 strings around (but just 1 continuos rope) to avoid every possible side torsion. The extensible lever came to mind because the word inextensible doesn't belong to real world, and the blades friction wouldn't increase noticeably.
c

Last edited by nocdplz; Today at 08:16 AM.
  Reply With Quote
Old Today, 05:18 PM   #4046
Mike56 is offline Mike56
diyAudio Member
 
Join Date: Apr 2020
Quote:
Originally Posted by nocdplz View Post
for me better 2 strings around (but just 1 continuos rope) to avoid every possible side torsion. The extensible lever came to mind because the word inextensible doesn't belong to real world, and the blades friction wouldn't increase noticeably.
c
You will recognise some of the parts, just a bit of drilling and filing from yesterday.
This is quite stable to handle, but i think the string is too thick, and although it falls (in warp direction) under its own weight it is much more friction full than yesterdays, however, one can see this is maybe not far off a working idea, would be easy to make and very inexpensive. Tomorrow i will search out some more flexible cord.
I think if the slots are hand filed like mine they, and the knife edge should be longer to avoid play in the VTA direction, alternatively work more accurately. Maybe the end plates in aluminium would work better as well in terms of filing.
I didn't glue the string at the back of the holes yet, this was just an experimental set up, hence the clip remains in place.
That's about 10mm of movement sat on the handle of the file, mike
Attached Images
File Type: jpg WIN_20200806_18_03_10_Pro.jpg (543.8 KB, 10 views)
File Type: jpg WIN_20200806_18_03_38_Pro.jpg (693.5 KB, 10 views)
__________________
PC, to Chordette GEM DAC or O.L. Aurora4 with Onyx arm Rega Ania to Graham Slee MC pre, to Prima Luna Prologue 1. Troels Gravesen Fusion BAD with Hypex 151's high level input
  Reply With Quote
Old Today, 07:23 PM   #4047
nocdplz is online now nocdplz
diyAudio Member
 
nocdplz's Avatar
 
Join Date: May 2010
Location: italy
2+2 - 0,25 mm dyneema or spectra string - (4 strings of this diam. may lift a person, and we are dealing with 10 15 grams)

Something like this: the spring lever may be really useful to share equally the loads on the two sides of the parallelogram, much better than rigid lever+ elastic strings. Different tensions drive to uneven vert movement.

ciao carlo
Attached Images
File Type: jpg mousetrap cart.jpg (70.2 KB, 0 views)
  Reply to this post

Reply


DIY linear tonearmHide 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
Linear tracking tonearm vs. Pivoting tonearm Don Nebel Analogue Source 5 31st May 2015 03:55 AM
Another DIY Tonearm johnmarkp Analogue Source 0 21st April 2008 11:07 PM
my DIY Turntables and DIY tonearm Roger Waters Analogue Source 57 22nd January 2008 06:05 PM
Magnetic suspension linear-tracking tonearm? Shaun Analogue Source 5 4th June 2003 10:21 PM


New To Site? Need Help?

All times are GMT. The time now is 07:31 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki