DIY turntable idea - 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 18th March 2004, 01:52 AM   #1
DeonC is offline DeonC  South Africa
diyAudio Member
 
DeonC's Avatar
 
Join Date: May 2002
Location: Kimberley, South-Africa
Default DIY turntable idea

Hi guys

I have been really inspired by the sight of Posthorn's DIY Turntable (see the following thread: Posthorn's DIY Turntable thread). Not that I really need another TT- I already have three good TTs, and with another one on it's way (I have a Technics SP10 MkII, Technics SP15, Linn LP12, and there is a Harman Kardon Rabco ST-8 on it's way to me) , but I found an old motor that I have lying around, and the DIY bug bit me again

The motor that I have is a huge old AC hysteresis motor. When I say large I mean that the motor is between 3" and 4" in diameter! It came from an old Akai reel-to-reel deck. How suitable do you guys think would this motor be for a DIY TT design? IOW, won't it be too noisy? I know that brushless DC motors are regarded as the best, but how does the AC hysteresis motor compare ITO suitability for a project like this?

The last question I have (for now) is slightly more philosophical- if you had this motor would you build a belt-drive or a direct-drive TT? Just curious. If I go ahead I'll probably build a belt-drive with a large flywheel (due to the high revolutions that the motor turns at- 1500RPM - 3000RPM). A flywheel will also help isolate the platter from motor-noise.

I would love to hear the comments and ideas

Deon
__________________
I don't suffer from insanity. I enjoy every minute of it.
Have a look at my favorite thread: Interesting YouTube video clips
  Reply With Quote
Old 18th March 2004, 06:25 AM   #2
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Quote:
The last question I have (for now) is slightly more philosophical- if you had this motor would you build a belt-drive or a direct-drive TT? Just curious. If I go ahead I'll probably build a belt-drive with a large flywheel (due to the high revolutions that the motor turns at- 1500RPM - 3000RPM). A flywheel will also help isolate the platter from motor-noise
Hi Deon

How can you possibly use this motor to build a DD table? 3000rpm?!

I think starting a TT design from the motor is simply wrong, even if you got it for free and have no other use for it. If are diying a TT you probably expect to end with something better than what you already have. The significant in both design and cost TT parts are the main bearing and the platter - a nice DC motor is dirt cheap in comparison. The flywheel add-on is probably great and with sufficient inertia may overcome some of the problems of the motor but this is more of a design afterthought.
So, what will you do about the main bearing?

regards
  Reply With Quote
Old 18th March 2004, 06:55 AM   #3
Raka is offline Raka  Europe
diyAudio Member
 
Raka's Avatar
 
Join Date: Aug 2002
Location: Close to Oistrakh
You can always build a low Hz power supply to reduce the speed of the motor, and build a large diameter pulley.
__________________
What is beyond the speaker?
  Reply With Quote
Old 18th March 2004, 06:29 PM   #4
DeonC is offline DeonC  South Africa
diyAudio Member
 
DeonC's Avatar
 
Join Date: May 2002
Location: Kimberley, South-Africa
Quote:
How can you possibly use this motor to build a DD table? 3000rpm?!
Well, it'd have to work through a 'gearbox', or basically the motor will drive a step-down gear, which will drive the platter. It can be made to work

Quote:
The significant in both design and cost TT parts are the main bearing and the platter
That part will remain whether I use the hysteresis motor or a DC motor. What I like about this motor is the sheer size. It is a BRUTE of a motor.

Quote:
The flywheel add-on is probably great and with sufficient inertia may overcome some of the problems of the motor
That's the point- I want to know if the hysteresis motor is worth working with. I want to know if it is worth it continuing. I can easily get a few second-hand TTs that will be used for the main platter and flywheel. You can still pick up old Lenco L70 and L75 TTs for a song (I had three at one stage), and they would be a great basis to start with. Stepping down from 3000RPM to 33 1/3RPM is a step-down of exactly 90 times.That is not so hard to achieve. The point is that the power of the motor coupled with the inertia of the two heavy platters will provide great speed stability.

Once again, this is not meant to be a reference TT (my Technics SP10 has that position), but simply a fun project.

Thanks,
Deon
__________________
I don't suffer from insanity. I enjoy every minute of it.
Have a look at my favorite thread: Interesting YouTube video clips
  Reply With Quote
Old 18th March 2004, 07:54 PM   #5
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Quote:
Once again, this is not meant to be a reference TT (my Technics SP10 has that position), but simply a fun project.
Please ignore my opinions above. I have no interest in killing time.
  Reply With Quote
Old 18th March 2004, 09:32 PM   #6
diyAudio Member
 
Join Date: Jul 2003
Location: Cologne
Thanks!

Don't forget the chain to drive your concrete platter on ship's propeler bearing ;-)

Hope you have some fun
  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
Bipolar stepper motor idea for custom turntable... binspaul Analogue Source 0 7th April 2009 09:43 AM
DIY - Turntable whubbard Analogue Source 17 8th March 2009 07:39 AM
An idea! Fully balanced TDA1541A DAC idea. Please comment! cartman Digital Source 8 17th July 2007 08:18 AM
Another DIY Turntable - maybe a new idea? JesseG Analogue Source 13 4th January 2006 04:29 PM
DIY Turntable ?'s LeBob Analogue Source 3 26th July 2004 03:32 AM


New To Site? Need Help?

All times are GMT. The time now is 08:45 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