Restoring and Improving A Thorens TD-124 MKII

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#1,622
his047 said:
I am a little confused by this since the Mørch GS6a (which has a bearing which, as far as I know, is a solid hollowed out bar of oilite) is lubricated with a mixture of axlegrease and sewing machine oil. Before Mørch decided on that mixture he used Molykote D paste but that gummed up after a few years, hence the change.
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Is an oilite "machined by removing" to shape it. Or is it some type of sintered metal matrix with voids and the basic shape is obtained during the sintering?
 
#1,624
Grease clogs the pores and if left long enough results in serious scoring of the spindle. I know this from rebuilding main bearings that had been lubed with grease. Only the early nylon bushings running dry and/or swelling does more damage.

In a properly rebuilt bearing the running surfaces run with a thin film of oil. Improper insertion of the spindle which knicks either of the bushings will result in scoring of the shaft and audible noise. (Pretty hard to avoid actually)

The default weight for modern oilite bearings is 30 wt SAE non-detergent oil, don't use regular motor oil as the additives may deteriorate over time resulting in gum and other nastiness. I change the 20 wt oil in the bearing well every year or so.

Thorens recommended an oil which was approximately equivalent in weight to 22 wt. The closest to this in the USA and Canada is 20 SAE 3 in One Electric motor oil. (see earlier in the thread for more information)
 
#1,625
AndrewT said:
Is an oilite "machined by removing" to shape it. Or is it some type of sintered metal matrix with voids and the basic shape is obtained during the sintering?
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I'm no expert, but oilite can be machined with very sharp tools and some care. All of the ones I have purchased show some evidence of final machining, but my understanding is they are cast close to the finished dimensions. Honing and reaming is a no no, as is anything that might tend to close up the pores. (Reaming can be done with a very sharp tool but is not recommended in most cases)

I run mine very wet, there is a running argument on this issue, but they seem to run quieter and wear a bit less. I have two of these tables, the nicer of the two is a total prima donna, the other one interestingly enough is not. Both are currently running really well.
 
#1,632
Esso ( Exxon ) themselves did that work for my old company. The boss of the research staion was a hi fi nut. My ex boss's father in law Dr Bowers suggested that the oil and phosphor bronze was the issue. Little crystals form and make audibal noises. Dr Bowers has just gone into a care home aged 88 with no idea of the life he had, lesson being enjoy life now. In 1952 his team perfected the fuel cell which was sold to NASA. An old idea made to work. His boss called Francis Bacon, a distant relative of another of that name it is said.
 
#1,636
It's a risk. Most oils sold today are for very different needs. My girlfriends VW Beetle ( new type ) shows how this can go wrong. Even given the correct oil it has develloped a high usage. This is killing the cat. Alas this is typical. Forced at some bar ( > 5 ? ) through very small gaps when cold being where it and the TD124 differ. Various additives sort that out ( or don't if VW ). These additives are the problem. Snake oils are often are motorcar oils.

The TD124 more so than any other turntable could run without oil ( phosphor bronze as many, nylon thrust being the big deal ). The very small trace of oil would be enough. The oil loading of the bronze sleeve bearings is at perhaps 80 C at the suppiler. This gets a charge of oil into the sponge like metal that soaking alone will not do. When the motor the oil needs topping up as the heat of the motor causes migration. In fact an oil change happens after oil is added due to tidal heat flow when motors. In the main bearing it is there for life and at best you will change it for the worse ( washing out of surface oil, errosion of intended type ). Lack of use is the worst thing. This seems to cause the oil to gel ( bacteria ? ). The Garrard motor will hit 70 C and is OK doing it. One that was run at double voltage by mistake for hours was OK. It must have been at 140 C, far too hot to touch. Garrard said 270/135 V was OK as in some countries it did go that high. 40 to 60 Hz 200 to 270 V ( 100 to 135 ). The 40 Hz is very useful if designing a 78 transcription turntable. The 40 Hz was said to be one area of the UK supplied by a local ICI chemical complex. Ironically this alone might have ensured the Garrard to be the better motor. Like amplifier transformers 40 Hz needs more magntic materials. The 50 Hz pulley will give 62 to 94 rpm if on a 40 to 60 Hz PSU. The 50 Hz pulley is better than the 60 Hz when possible to have the choice. As the TD124 motor is a similar type it is easy to say as Garrard. The lubrication hole in the TD124 motor often gives out green oil when in use for the first time after oill added. The hole is at the bottom. A small screwdriver will get it in, use plenty. If brave and opening the motor it might jam when tightened. Just leave it a bit loose is the answer. Have another go when hot. Best still, don't open it. The top bearing is under the pulley. It is easy to ge at. Often this green oil means you got there just in time. Sometimes not.

Here is the untold story. The oil will chage the sound. The right oil will be like a better stylus. Bass will be more noticable, also micro detail. Flutter is reduded. Oils like SAE 20 and 30 are about the right choice. EP80/90 unlikely to be the best. Sewing machine oil works very well as would clock oils for the larger types. Some oils slow the turntable by about 0.1%. That might be too much sound wise. A little slowing is a good thing. An SAE 10 or 5 might be too thin to get the motor working best. Mr Verdier thought drag to be very helpful. His belief was that the stylus drag which varries is then ignored by the motor. This seems possible ( a vector of effects where the drag is the dominant force ). The hysterisis motor type fitted to TD124 and Garrard likes a bit of a load more than a synchronous motor would ( LP12 and many, DD also ). Verdier used Rocol lathe slide bed oil. That says a lot for the man ( alas not with us now ). Knowing lathes told him it was a good oil.

Linn LP12 needs oil. PTFE can cause much trouble without oil. Without oil it needs a very hard shaft. The LP12 shaft is harder than the Garrard and I suspect the TD124. Even so the PTFE shows a wear ridge on LP12's. Even when using black Molyslip oil! I have no idea if Molyslip would be OK in a TD124 or how to buy it. I suspect the older black Linn oil would be fine? Who knows if what is sold on eBay is correct?
 
#1,639
I have no idea. Here in the link is something that might make sense from other doubters. As said by them ceramic is super hard. It normally would be avoided. I guess it is not a strict ceramic. the one they suggest might be like Molyslip original. This reminds me of food in the 1960's. If it's processed it must be better. What people forget is the bearings and oils were made for each other. Much is a lost art.

Ceramic in engine oil? | Oil Industry and Related News | Bob Is The Oil Guy
 
#1,640
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