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 20th February 2007, 09:07 PM   #1
diyAudio Member
 
Join Date: Apr 2006
Location: Goulburn NSW
Default Origami Idler Drive?

There has been some discussion over on the vinyl engine on what makes TTs have their distinctive sound and from this and other papers I have read on the subject it seems the idler drive might actually be the best system, but as they are pretty much all old designs now they are hampered by rough motors and poor bearings that were in use in their day.

It occurred to me that maybe the floppy drive motor might be the ideal cadidate for the job, at first I thought is would be hard to set up, but thinking about it, if the speed can be varied electronically then a lot of the potential problems of the idler would go away, as you would just need a fixed straight shaft running against the idler neither the motor nor the idler would need to be raised in relation to one another to adjust speeds, so all sorts of brackets and knobs and springs are deleted.

I imagine the floppy drive would be far smoother than the original motors as well and this is probably even more important to an idler drive than it is to a belt drive.

Possibly other similar motors like video head motors might be even better, though I have no idea how you would control the speed.

Anyone tried to floppy their idler?
  Reply With Quote
Old 21st February 2007, 11:24 AM   #2
diyAudio Member
 
Join Date: Dec 2005
Location: essex
I use an idler (a lenco heavily modified).

The motor is very smooth and quiet, but getting rid of the idler movement and the conical shaft has got to be a good thing.

Idlers do need (or at least benefit) from quite alot of torque though. How strong are the floppy motors?
  Reply With Quote
Old 21st February 2007, 12:01 PM   #3
diyAudio Member
 
Join Date: Apr 2006
Location: Goulburn NSW
Ji Graeme

Not sure how torquey floppy drives are but I imagine they are pretty reasonable. I guess since they can be speed adjusted that a smaller shaft could be used and a higher rotational speed if low speed torque is insufficient. Of course this would be a little noisier.

As I understand it the older 5 inch floppy drive motors are a bit stronger.

There are also lots of stepper motors out there some of which are amazingly powerful and smooth though I guess controlling them becomes an issue. Some of those can run at very low revs too, so a larger pinion could be used and maybe lower vibration/noise as a result.

Another possible motor could be a video head motor, though once again I think speed control is a bit tricky from what I have heard, there is also the capstan drive which from memory has a small vertical shaft as part of the package, not sure what speed they operate at though.
  Reply With Quote
Old 21st February 2007, 12:27 PM   #4
diyAudio Member
 
Join Date: Dec 2005
Location: essex
worth looking into by the sounds of it, although making a new TT just using a lenco or garard motor would be easier. I really dont think the motors are that bad. My lenco is speed stable and very quiet. The lenco drive is easier to use in a home built TT as it drives the underside of the platter rather than the inner lip meaning driving a different platter on a different bearing (what ive done) is very easy.

As you say though, having a solid mounted idler and a straight motor shaft might be beneficial.
  Reply With Quote
Old 21st February 2007, 08:14 PM   #5
diyAudio Member
 
Join Date: Jun 2004
Location: Adelaide Australia
Before you indulge in the obvious need to tweak I would advise some strong words of caution.The Lenco motor and drive system is advocated by the guy (Jean Nantais) who brought them back out of the dark ages as being near perfect.What you need to address is the issue of a good mass plinth and good tonearm.You will then beat the best the world has to offer.
  Reply With Quote
Old 22nd February 2007, 12:30 AM   #6
phn is offline phn  Sweden
diyAudio Member
 
phn's Avatar
 
Join Date: Oct 2004
I agree. We need to put the "idler-wheel rumble" myth to rest. People would hardly pay the money they do for EMTs and Garrards if they had rumble problems.

Designing an idler-wheel deck sounds cool. But it probably won't be easy. Perhaps the best solution is a Japanese deck I saw in a hi-fi rag in the mid 1980s. I don't remember who made it. I do remember it being VERY expensive.

Maybe this is known to everybody. But I haven't seen the deck since. It had a metal platter, probably 10 cm thick. On the otside there was this drive shaft/rod, also 10 cm. The idler-wheel was magnetic. It was basically a rubber-insulated magnetic rod. But even that might not be simple. Chance is that the driving rod/wheel will have to be floating somehow.
  Reply With Quote
Old 24th February 2007, 02:15 PM   #7
amsci99 is offline amsci99  Singapore
diyAudio Member
 
Join Date: Jan 2006
Location: Western region
Quote:
Originally posted by phn
I agree. We need to put the "idler-wheel rumble" myth to rest. People would hardly pay the money they do for EMTs and Garrards if they had rumble problems.

Designing an idler-wheel deck sounds cool. But it probably won't be easy. Perhaps the best solution is a Japanese deck I saw in a hi-fi rag in the mid 1980s. I don't remember who made it. I do remember it being VERY expensive.

Maybe this is known to everybody. But I haven't seen the deck since. It had a metal platter, probably 10 cm thick. On the otside there was this drive shaft/rod, also 10 cm. The idler-wheel was magnetic. It was basically a rubber-insulated magnetic rod. But even that might not be simple. Chance is that the driving rod/wheel will have to be floating somehow.
phn,

I think you are referring to the Teragaki designed Seiko-Epson Sigma series turntables. The Sigma 2000 was released in 1987, followed by the Sigma 3000 and 5000 in 1994. Very limited edition models, only about 30 to 40 units were made and the Sigma 5000 costed about 32,000,000 Yen when released. I have been trying to locate magazines which reviewed this deck but unfortunately was unable to find any.
Attached Images
File Type: jpg 5000_yj2.jpg (39.2 KB, 745 views)
  Reply With Quote
Old 24th February 2007, 02:59 PM   #8
phn is offline phn  Sweden
diyAudio Member
 
phn's Avatar
 
Join Date: Oct 2004
It could be Teragaki. I couldn't say. I googled Teragaki Seiko-Epson Sigma. There are quite a few of these ultra high-end decks out there. Back when I saw this deck, Thorens and Nakamichi were pretty much the only ones to make these kind of "prestige" decks. That's probably not true. But there were a lot fewer manufacturers back then.
  Reply With Quote
Old 26th February 2007, 04:25 AM   #9
diyAudio Member
 
Join Date: Apr 2005
Location: Wellington
I think idler wheel with a DC motor is pointless.
The advantage of idler wheel over direct drive is the synchronous or induction motors they use which don't need a feedback system and therefore don't 'hunt' for the correct speed.
  Reply With Quote
Old 4th March 2007, 02:29 AM   #10
mosin is offline mosin  United States
diyAudio Member
 
mosin's Avatar
 
Join Date: Nov 2003
Location: US
Quote:
Originally posted by Aquarium
Before you indulge in the obvious need to tweak I would advise some strong words of caution.The Lenco motor and drive system is advocated by the guy (Jean Nantais) who brought them back out of the dark ages as being near perfect.What you need to address is the issue of a good mass plinth and good tonearm.You will then beat the best the world has to offer.
Hello,

I have built a turntable that uses the Lenco as a starting point, and I strongly question the notion that blindly accepts the motor and drive system as being near perfect. Rather, I consider the Lenco motor to be an inferior one. First, it is a shaded pole type. The shaded pole motor itself is vastly inferior to a three-phase eddy current type, like the Papst Aussenlaufer, for example. Second, it relies on a steel pin pushed by a spring, in place of a proper thrust bearing. The thrust pin is particularly prone to sticking in place after time has past. Third, lubrication is unsure, at best. Lenco's spindle and bearing system is also troublesome, in my honest opinion. It is imprecise and leaky. It is also fairly small, considering the claims that have been made about the turntable. Last of all, the platter rings like a bell, and all the metal stampings are pedestrian in quality. Asking a heavy plinth to fix all those issues without making serious other modifications is a bit preposterous.

So, although the Lenco can be made much better, it is not what some claim it to be. What it is, however, is a turntable with a single idea that shows immense potential, and that is its implementation of a thin wheel that runs on the underside of the platter, rather than the rim. Although Lenco's idler isn't so great, this particular idler wheel concept when combined with other improvements can take the idler turntable to highs that it has never seen before. Think about it.

-mosin
  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
IDLER WHEEL DESIGN-Just the idler... kozzmo99 Analogue Source 8 7th September 2009 06:41 PM
Modding a DD motor for belt/idler drive Capt Zach Analogue Source 0 2nd July 2007 02:15 PM
Help, I am falling in love with an idler tt! Triumph Analogue Source 56 14th November 2006 11:22 PM
DIY Idler Drive...... Paul Dimaline Analogue Source 14 12th December 2005 10:15 PM
Idler wheel drive vs. Belt-drive mig-ru Analogue Source 4 3rd December 2003 12:06 AM


New To Site? Need Help?

All times are GMT. The time now is 05:12 PM.


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