UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Audio (record players, hi-fi etc)

Notices

Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment.

Closed Thread
 
Thread Tools
Old 5th Oct 2017, 6:37 pm   #1
RojDW48
Nonode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 2,074
Default Idler wheel for Decca RP from the dawn of 33rpm

This early (possibly experimental) Deccalian has featured here before with much discussion about how to remove the platter. Now Ed Dinning has kindly rewound its set of pick up heads, I am trying to get it going. The idler, as you can see, is pretty much shot. I have tried harvesting from my selection of dead decks but the spindle is too big for any of them at 7/16" diam. Does anyone have such a wheel - or a suggestion as to where I might get it re-rubbered?
Attached Thumbnails
Click image for larger version

Name:	DSC05447.jpg
Views:	202
Size:	78.6 KB
ID:	150384   Click image for larger version

Name:	DSC05448.jpg
Views:	174
Size:	63.6 KB
ID:	150385   Click image for larger version

Name:	DSC05449.jpg
Views:	160
Size:	62.6 KB
ID:	150386  
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline  
Old 5th Oct 2017, 11:42 pm   #2
emeritus
Dekatron
 
Join Date: Jan 2012
Location: Brentwood, Essex, UK.
Posts: 5,316
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Is the idler like a pulley with the rubber located in a groove? Polyurethane drive belts of various diameters are available that can be cut to size and joined by melting, and are available in both rough and smooth finishes.

I bought a selection from RS some years ago. Their current offerings are here:

http://uk.rs-online.com/web/c/pneuma...m=drive%20belt
emeritus is offline  
Old 6th Oct 2017, 12:56 am   #3
Techman
Dekatron
 
Techman's Avatar
 
Join Date: Nov 2009
Location: Lincolnshire, UK.
Posts: 4,985
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

This company called "Terry's Rubber Rollers" (or similar name) gets mentioned a lot on the forum, for rebuilding idler wheels, but I doubt it would be cheap.
Techman is offline  
Old 6th Oct 2017, 7:46 pm   #4
RojDW48
Nonode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 2,074
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Thanks for the info - Terry's rollers do look a bit expensive, but they could probably do it. The idler is sort of the opposite of a pulley - the rubber 'sleeve' appears to fit around the metal wheel - ie the rubber is recessed so that the wheel rim fits into it. Also, I must invest in new spectacles - the spindle diameter is, of course, 7/32"!
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline  
Old 7th Oct 2017, 9:29 am   #5
llama
Octode
 
llama's Avatar
 
Join Date: Jun 2006
Location: St Osyth, Nr Clacton, Essex, UK.
Posts: 1,482
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Looks like some of the 3mm O-ring cord I've just ordered off ebay might do the job. You could super-glue the ends (which I intend to do) to make a tyre of the appropriate length and slip it over the metal rim. When mine arrives I'll send you the odd 7 inches (or whatever) if you like.
Graham
__________________
Half my stuff is junk - trouble is, I don't know which half!
llama is offline  
Old 7th Oct 2017, 8:07 pm   #6
RojDW48
Nonode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 2,074
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Hello Graham - that is very kind of you. The wheel consists of a central boss just under 1 3/4" in diameter with what looks like a 'plastic waste pipe' washer glued to the outside. I have tracked down a rubber washer manufacturer (inventively called 'Rubber Washers') who purport to make up bespoke washers, which might be ideal. I shall give them a call Monday to see what they can do, but I shall bear your kind offer in mind.
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline  
Old 7th Oct 2017, 8:45 pm   #7
Ed_Dinning
Dekatron
 
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,173
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Hi gents, there used to be a series of castable rubbers made by a company called Devcon, not sure if they are still around but that might be a solution; cast a new one and machine up in a lathe afterwards to get concentricity.

Ed
Ed_Dinning is offline  
Old 8th Oct 2017, 7:01 am   #8
TonyDuell
Dekatron
 
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,191
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

The Devcon Urethane 'rubbers' do still exist, in fact RS sell some of them. But they are not cheap. You probably need the primer as well which doubles the cost. Figure on around £100 for the materials.

The main problem is that the instructions now tell you to mix the entire pack (500g of stuff) which is far too much for one roller. And once mixed you have to use the lot in half an hour. At one time they suggested you could weigh out part of the pack and mix it but apparently the results of so doing were not that good. Also Iseem to remember the shelf life of the opened but unmixed stuff was not that long.
TonyDuell is online now  
Old 8th Oct 2017, 7:25 am   #9
dseymo1
Retired Dormant Member
 
Join Date: Dec 2007
Location: Shropshire, UK.
Posts: 3,051
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

I use stuff known as PU16 for all sorts of things. It's sold as a sealant, but also works very well as an adhesive. Essentially, PU 'rubber' in a cartridge, It's air (moisture) curing, but could probably be used in a similar way to Devcon for this sort of job.
dseymo1 is offline  
Old 8th Oct 2017, 8:01 am   #10
Hartley118
Nonode
 
Hartley118's Avatar
 
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,196
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

A few years ago, the main rubber drive wheel of my 8mm film projector turned to goo. I repaired it by cutting a slice of suitable diameter car radiator hose and gluing it onto the metal core wheel with superglue. It was then a matter of smoothing it down by fixing the wheel in the chuck of an electric drill and using various grades of wet & dry paper to grind it down as it rotated.

That wheel still works fine in the projector to this day.

I've never tried this technique to restore a turntable idler, but it should be possible. Exact diameter will be unimportant to speed because it's only an idler. However, a smooth finish would of course be important to minimise noise and vibration. Might be worth a try to get this rather good turntable running again.

Martin
__________________
BVWS Member
Hartley118 is offline  
Old 8th Oct 2017, 8:21 am   #11
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Just a thought. I used to buy packs of video recorder idler tyres from SEME. They came in very useful for other applications. They may still be available from other suppliers . John.
PS What size is the actual 'tyre. I will have a look in Pandora's box.

Last edited by Heatercathodeshort; 8th Oct 2017 at 8:31 am. Reason: Added info.
Heatercathodeshort is offline  
Old 8th Oct 2017, 1:18 pm   #12
RojDW48
Nonode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 2,074
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Lots of good ideas gents! I have added a couple of pics that show the metal bit to be some kind of pressing 1 3/4" diameter and the 'tyre' is near enough 3mm X 3mm though, as Martin writes, the width is not critical. There is no rebate in the inner rim of the tyre - it just looked like there was before I pulled it off. Thanks for the interest - I have re-furbed 2 older (78rpm) versions of this Deccalian with multi-speed decks - well worth the effort - the amps and cabinets are very good indeed.
Attached Thumbnails
Click image for larger version

Name:	DSC05450.jpg
Views:	99
Size:	112.9 KB
ID:	150484   Click image for larger version

Name:	DSC05451.jpg
Views:	89
Size:	74.0 KB
ID:	150485  
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline  
Old 8th Oct 2017, 5:58 pm   #13
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Sorry, can you let me have the diameter of the wheel less the tyre. John.
Heatercathodeshort is offline  
Old 8th Oct 2017, 6:03 pm   #14
RojDW48
Nonode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 2,074
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

The wheel is 1 3/4" diameter (without the 'tyre'). Apologies for the confusion.
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline  
Old 9th Oct 2017, 8:26 am   #15
Heatercathodeshort
Dekatron
 
Heatercathodeshort's Avatar
 
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,145
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

It's such a pity but we did not know it at the time. I mentioned earlier that SEME used to stock a large number of video reel idler tyres. I should have ordered a dozen packs of each!

There was a very large range from small to large. They were very cheap and came in useful when the original complete idler was out of stock or unobtainable.

I have just a few remaining in my NOS stock. You are welcome to one of these FOC if you think you can use it. They are flexible so maybe a chance.

I cannot believe these are not available in some form. They must be used in all manner of industrial machines throughout the World! Regards, John.
Attached Thumbnails
Click image for larger version

Name:	DSCN7229.jpg
Views:	88
Size:	32.8 KB
ID:	150512  
Heatercathodeshort is offline  
Old 9th Oct 2017, 1:48 pm   #16
RojDW48
Nonode
 
RojDW48's Avatar
 
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 2,074
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Thanks John - I have tried using a waste pipe washer of similar dimensions but it distorted too much when stretched to fit over the wheel. I have yet to contact Rubber Washers but I am rushing to catch a plane to sunny Spain later today, so I'll need to come back to this in 10 days time. As you write - there must be something out there that I can adapt to this simple purpose!
__________________
'....don't go mistaking Paradise for that home across the road!' (Bob Dylan)
RojDW48 is offline  
Old 9th Oct 2017, 9:36 pm   #17
astro63
Pentode
 
Join Date: Mar 2013
Location: Norfolk, UK.
Posts: 248
Default Re: Idler wheel for Decca RP from the dawn of 33rpm

Just a thought what about o-rings them rubbery black washers
astro63 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 10:06 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.