morloch Posted March 1, 2020 Share Posted March 1, 2020 (edited) Hard to believe this film exists. Enjoy! Edited March 1, 2020 by morloch 17 1 Link to comment Share on other sites More sharing options...
muon* Posted March 1, 2020 Share Posted March 1, 2020 That was cool Link to comment Share on other sites More sharing options...
stevoz Posted March 2, 2020 Share Posted March 2, 2020 Be interesting to know what happened to the "several hundred" Commomwealth TT's that the ABC had. Going by what they did to early Countdown video tapes, the TT's probably ended up in landfill in the mid 80's.....all replaced by crappy CD players. Anyone know the truth? 2 1 Link to comment Share on other sites More sharing options...
glenm64 Posted March 2, 2020 Share Posted March 2, 2020 A glimpse to another world. I love the machining part were they have swarf flying about, its in his hair etc, but no safety glasses. Even more impressive is he has a cardigan and tie on under his workshop coat. 4 1 Link to comment Share on other sites More sharing options...
audiofeline Posted March 2, 2020 Share Posted March 2, 2020 (edited) 4 hours ago, stevoz said: Be interesting to know what happened to the "several hundred" Commomwealth TT's that the ABC had. Going by what they did to early Countdown video tapes, the TT's probably ended up in landfill in the mid 80's.....all replaced by crappy CD players. Anyone know the truth? A former ABC engineer has two, which are now used for his audio restoration project work at the Australian Jazz Museum in Wantirna, Vic. Edited March 2, 2020 by audiofeline 2 Link to comment Share on other sites More sharing options...
audiofeline Posted March 2, 2020 Share Posted March 2, 2020 (edited) This is a great find. There is also a small clip of the factory in Hobart in the National Sound Archives. The clip on the web is extremely small/low res. Edit: It's in the Tasmanian archives. Home film by Lindsay McCarthy, 8mm slilent, "....Commonwealth electronics factory behind Phillips show room Moonah showing record turntables and parts". Can't find the small clip I've seen before. https://librariestas.ent.sirsidynix.net.au/client/en_AU/tas/search/detailnonmodal/ent:$002f$002fARCHIVES_ITEMS$002f0$002fARCHIVES_ITE_DIX:NS5551-1-6/one Edit: Have just chatted to them online about the availability for viewing this clip online: Quote Operator No, this film has not been digitised and is not available online. Operator You can request a copy via our copy service, at a cost of $44.00 Operator Here is a link to our copy service page Operator https://libraries.tas.gov.au/how-to/Pages/copies-holds.aspx Edited March 2, 2020 by audiofeline 1 Link to comment Share on other sites More sharing options...
Colin Rutter Posted March 2, 2020 Share Posted March 2, 2020 Thanks for the "film" The Commonwealth's main plus is that it gets up to full speed in the twinkling of an eye. Which is what a radio broadcaster needs. The rumble was easily filtered at the transmission end and certainly would not be reproduced at the radio end. Early hi-fi equipment came with rumble filters for these type of TTs. Link to comment Share on other sites More sharing options...
audiofeline Posted March 2, 2020 Share Posted March 2, 2020 14 minutes ago, Colin Rutter said: Thanks for the "film" The Commonwealth's main plus is that it gets up to full speed in the twinkling of an eye. Which is what a radio broadcaster needs. The rumble was easily filtered at the transmission end and certainly would not be reproduced at the radio end. Early hi-fi equipment came with rumble filters for these type of TTs. In a good plinth there is no rumble to speak of in these turntables. Unfortunately because of the cheap idler record changers polular in the 60/70's (which did have a lot of rumble and required rumble filters on home amps), many people assume that all idler turntables have excessive rumble - which is untrue. Professional idler turntables like the Commonwealth, Byer/Rola, etc. are as silent as top-quality dd/belt turntables. 3 Link to comment Share on other sites More sharing options...
Colin Rutter Posted March 2, 2020 Share Posted March 2, 2020 7 minutes ago, audiofeline said: In a good plinth there is no rumble to speak of in these turntables. Unfortunately because of the cheap idler record changers polular in the 60/70's (which did have a lot of rumble and required rumble filters on home amps), many people assume that all idler turntables have excessive rumble - which is untrue. Professional idler turntables like the Commonwealth, Byer/Rola, etc. are as silent as top-quality dd/belt turntables. Not to my ears. But that doesn't mean I don't like them. I have the best of the PE tts. 1 Link to comment Share on other sites More sharing options...
Peterbean Posted March 3, 2020 Share Posted March 3, 2020 I saw one at a garage sale here in Canberra years ago, but someone beat me to it- the same guy who found a pair of Tannoys at the tip, that had belonged to the guy who developed the fast breeding reactor ( our first Nobel prize winner I think) 1 1 Link to comment Share on other sites More sharing options...
VanArn Posted March 3, 2020 Share Posted March 3, 2020 The eight pole hysteresis motors used with the Commonwealth Electronics turntables results in a transition of a 22.52. Hz vibration frequency at 33 1/3 RPM. The compliance of the rubber idler and the flywheel effect of the heavy platter results in very low rumble for this product and it has never been a matter of concern. 2 Link to comment Share on other sites More sharing options...
jdog Posted April 12, 2020 Share Posted April 12, 2020 Hi Guys, Today i bought a Commonwealth 12-c turntable from a deceased estate. Gentleman was apparently an engineer for ABC, and kept this as a spare as It looks unused with its original box,..However, its missing the idler wheel. Does anyone have any experience getting these milled by someone or a company? Or anyone has spares sitting around willing to sell it? I am referring to below: I have only got it today, and briefly plugged it in, and it seems like the motor is not turning.. not sure if the motor is toast, or any other component, i will check.. If the motor is toast, do you guys know any motor winding people/company in Sydney? I will try to take some pictures and will post it back.. Thank you for your help! J 1 Link to comment Share on other sites More sharing options...
Telecine Posted April 12, 2020 Share Posted April 12, 2020 (edited) Congrats on the purchase. Bad luck about the problems. Any machine shop shop should be able to machine you up an idler wheel if you can obtain the dimensions. A rubber O Ring can be used around it to drive the platter. The problem with the motor not running may be electrical. You will need to check that the microswitch is supplying power to the motor. If no electrical problem can be found. You may need to strip the motor down and lubricate it. Edited April 12, 2020 by Telecine Link to comment Share on other sites More sharing options...
Monkey_Relish Posted April 12, 2020 Share Posted April 12, 2020 I think this guy may be able to help :- Commonwealth Electronics Restoration Mr Relish 1 Link to comment Share on other sites More sharing options...
audiofeline Posted April 12, 2020 Share Posted April 12, 2020 1 hour ago, Monkey_Relish said: I think this guy may be able to help :- Commonwealth Electronics Restoration Mr Relish Chris' restoration was on a CE 12D, not a 12C. I'm not sure of the differences. Congratulations on your purchase, Commonwealths are amazing tt's. Do you mind if I ask if you got it for a deceased-estate price? Did you get any other gear while you were there? Did you get a manual and/or any other documentation with it? If so, it would be good to scan it and upload it to Vinyl Engine, there is little documentation from these turntables surviving and in circulation. It would help preserve some of our audio history which hasn't been documented. 1 Link to comment Share on other sites More sharing options...
Mat-with-one-t Posted April 12, 2020 Share Posted April 12, 2020 I may have access to documentation. I’ll look into it. This is a friend of a friend’s desk......oooohhhhh.... 2 1 Link to comment Share on other sites More sharing options...
audiofeline Posted April 12, 2020 Share Posted April 12, 2020 Those Byers look nice. I need a cold shower after seeing all the hammertone on the idlers. 1 1 Link to comment Share on other sites More sharing options...
jdog Posted April 15, 2020 Share Posted April 15, 2020 I managed to get the motor working, weirdly even the light works.... some contact cleaner did the trick.. only thing i am missing is the idler wheel now (and the plinth, and the tonearm, and the phono stage, but its all part of fun isnt it?) Does anyone have 12b or 12 c where they can measure up the idler wheel for me by any chance? I have found some people that could build it for me, but need the measurements.. 9 1 Link to comment Share on other sites More sharing options...
aussievintage Posted April 15, 2020 Share Posted April 15, 2020 I love working on these old idlers. Yours looks beautiful. I'd have liked a commonwealth, but have never scored one. I am quite happy with my Rek-o-Kut B16-H though. I was just wondering. Most true idlers are not critical in their outer diameter at all. Could you measure the shaft and so figure out the inner diameter, then guesstimate the required radius by examining the working of the speed change mechanism and also calculating it's size relative to other things in the picture above? This is if no-one can tell you what it really should be. Link to comment Share on other sites More sharing options...
jdog Posted April 15, 2020 Share Posted April 15, 2020 12 minutes ago, aussievintage said: I love working on these old idlers. Yours looks beautiful. I'd have liked a commonwealth, but have never scored one. I am quite happy with my Rek-o-Kut B16-H though. I was just wondering. Most true idlers are not critical in their outer diameter at all. Could you measure the shaft and so figure out the inner diameter, then guesstimate the required radius by examining the working of the speed change mechanism and also calculating it's size relative to other things in the picture above? This is if no-one can tell you what it really should be. Yes that would be the way to go if i cant find the specs.. from what i read, idler wheel size does not really make any difference to the speed of the turntable as long as it transfers the motor rotation to the rim, so couple of mm should not be an issue.. that said, i was searching the interwebs and found a lovely gentleman in QLD that has the same tt and he will be measuring the wheel and send me some drawings.. Same gentleman got one made by an engineer in Russia (pic below), but i prefer to keep my money in AU, so any recommendations for an engineering company/engineer that could mill this would be appreciated.. 1 Link to comment Share on other sites More sharing options...
aussievintage Posted April 15, 2020 Share Posted April 15, 2020 5 minutes ago, jdog said: from what i read, idler wheel size does not really make any difference to the speed of the turntable Yes, from a purely ideal mechanical point of view, a rubber idler that sits between a driven shaft (motor) and a second circular item (platter), has no effect, and the final speed is purely the ratio of the driven shaft's and the final item's diameter. Link to comment Share on other sites More sharing options...
VanArn Posted April 15, 2020 Share Posted April 15, 2020 (edited) The 12D idler measures as follows:- the overall diameter of the rubber tyre is 3.75 ''. The inner diameter of the tyre is 2.7 " . The tyre was bonded to an aluminium disc of .085 " thickness and a diameter of 3". The sintered 0.375 " o.d.. bronze bearing bush is 0.75 " long. This is held in place by a two piece aluminium boss of approx. 0.725 '' o.d. These appear to be pressed together, one section with a 'T' cross-section fitting into the other cylindrical piece. The height either side of the aluminium disc is 0.3125 ''. I left out the tyre, thickness which is 0.215 '' Edited April 15, 2020 by VanArn Omission 2 Link to comment Share on other sites More sharing options...
jdog Posted April 15, 2020 Share Posted April 15, 2020 30 minutes ago, VanArn said: The 12D idler measures as follows:- the overall diameter of the rubber tyre is 3.75 ''. The inner diameter of the tyre is 2.7 " . The tyre was bonded to an aluminium disc of .085 " thickness and a diameter of 3". The sintered 0.375 " o.d.. bronze bearing bush is 0.75 " long. This is held in place by a two piece aluminium boss of approx. 0.725 '' o.d. These appear to be pressed together, one section with a 'T' cross-section fitting into the other cylindrical piece. The height either side of the aluminium disc is 0.3125 ''. I left out the tyre, thickness which is 0.215 '' wow thank you so much.... i know visually 12 b and 12 c idlers look same, but 12d seems different.. one on the left is from b or c, one on the right is d.. there is a little bearing on top of 12-c idler shaft and idler sits on top of it.. Link to comment Share on other sites More sharing options...
VanArn Posted April 15, 2020 Share Posted April 15, 2020 I could not find anything concerning the dimensions of the later idlers. The design of the 12C version appears to have reduced the amount of machined parts by eliminating the two part boss holding the sintered bronze bush and also allowed the drive assembly to have a lower profile. It is likely it also reduces the tendency for the idler to move up and down on its shaft due to free play. I am reasonably sure that the critical dimensions of the motor pulley , inner platter rim diameter and spacings of the 12C are the same as the earlier model. 1 Link to comment Share on other sites More sharing options...
jdog Posted April 15, 2020 Share Posted April 15, 2020 19 minutes ago, VanArn said: I could not find anything concerning the dimensions of the later idlers. The design of the 12C version appears to have reduced the amount of machined parts by eliminating the two part boss holding the sintered bronze bush and also allowed the drive assembly to have a lower profile. It is likely it also reduces the tendency for the idler to move up and down on its shaft due to free play. I am reasonably sure that the critical dimensions of the motor pulley , inner platter rim diameter and spacings of the 12C are the same as the earlier model. thank you so much for the info.. makes sense re-freeplay.. its also good to have this information logged here on stereonet for future generation use.. Link to comment Share on other sites More sharing options...
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