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Thread: Can you improve the stock techie bearing???

  1. #21
    Join Date: Feb 2009

    Location: Worthing

    Posts: 75
    I'm James.

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    I agree that Mike's housing is probably stiffer, I'm just struggling to see how the standard housing isn't stiff enough in normal use. I really don't think it affords any sort of deflection which could affect the platter remaining perpendicular to the bearing's axis. The housing possibly affects any mechanical noise transmitting through the bearing shaft to the platter? I'm not sure.

    I think the biggest problem is probably the thrust pad, and lack of oil bath.

  2. #22
    Mike_New Guest

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    Hi James,
    I spent some time studying the design and engineering aspects of the bearing, please believe me when I say, "it aint much good for quality sound".
    See the recently opened thread by Stephen.

  3. #23
    Join Date: Nov 2008

    Location: Banbury, Oxfordshire/Panteg is where my late father was born

    Posts: 4,382
    I'm Chris.

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    Hi Mike , with due respect it must at least be good enough or fit for purpose ?

    You say and have always said and I quote ' a turntable stands or falls by the quality of its main bearing '
    If all this is true and SL1200 bearing is piss poor ? Then I've wasted my time and money on the 1210 ? But I don't think I have , though I have arguably the cheapest mods available , I'm at that point where I don't think I should throw any more money at it ? If I want something better , maybe look at other decks .
    Chris

    We've gone on holiday by mistake !

  4. #24
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

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    Ok as promised, this is my take on DIY modifications for the Technics SL-1200 Bearing.
    Hope you don’t mind me adding this to your Thread Ian? It seemed logical to keep it all together so people can locate it easily.

    I started by looking at the bearing used in the sl-1300/1500/150 etc. illustrated below.
    To see if this could be adapted.



    There are three things I prefer about this bearing to the stock 1200 bearing:

    1). It has a large round flange, so it would be possible to mount it with a gasket over the standard pocket in the top plate (pic2). You could then fill it with oil right up to the neck and fully lubricate the bush and thrust pad.

    2). There is a collar around the top edge that creates a small well (pic1) that can hold a small quantity of oil, so you can overfill and have oil in reserve.

    3). The plate supporting the thrust pad has three fixings rather than two (pic3).

    The reason I didn’t develop this idea was the scarcity of this bearing compared to that of the 1200, in fact I found it difficult to find pictures of it. Also the support pillars for the motor (pic1) look to be shorter and don’t have a second step to support the 1200’s PCB. Without having one to examine more closely it is difficult to tell if there are any other differences. If anyone has one of these bearings lying around, they could check if it’s a possible donor along these lines.

    Right, that leads me back to the stock offering for the 1200 - I bought a new one to modify. These mods can be tackled by anyone with reasonable DIY skills and only the most basic of equipment – small bench drill, belt or disc sander, electric drill with flexible drive is optional and hand tools including an M3 thread tap, I had an old mechanics set I bought from “Machine Mart” about 6 years ago. My workshop is my kitchen table and a “workmate” table/vice used in the yard – weather permitting. So don’t be put off, thinking you need fancy facilities, a lathe and milling machine, you don’t.



    The tip of the bearing can be quite badly pitted, even from new, but this one wasn’t bad (pic top right), I gave it a polish anyway.



    I don’t like the thick oil principle and lack of lubrication to the thrust bearing pad so decided to do something about it.
    I started by creating some keying features in the casting and making a dam across the open face to hold in some filler/glue.



    As can be seen above, I glued in a piece of 1” Aluminium bar, in which I had drilled a 12mm hole. I glued everything with Plastic Padding’s “Chemical Metal”. This stuff is strong, oil resistant and good up to 160 deg C. I now have a gasket face to help keep the oil in.



    These shots show the M3 tapped holes that hold the thrust plate in place, you really need some form of drill press to make sure the holes are drilled perpendicular to the face. Also shown is the collar I added around the top of the bush bearing to hold a small qty of oil in reserve.



    The plastic thrust pad will be replaced with one of these metal shims, can you spot the one I polished? LOL. These are for setting valve clearances on a motorcycle engine and are easily obtainable, dia. 7.5mm x 1.5mm thick. Using a steel shim in place of the plastic pad is an upgrade I am familiar with on Thorens bearings. They do run quieter this way but obviously have to be in an oil bath.



    The shim is located in a pocket created by drilling a hole in a 1.2mm Brass sheet. This sheet is then glued to a 3mm Brass sheet with, you’ve got it, Chemical Metal. The sandwich was then drilled to take the four fixing screws and cut to the correct shape. I made a gasket from 0.4mm gasket paper and located the shim in the pocket with a spot of silicone instant gasket. If you don’t do this it tends to stick to the spindle when lifted, due to oil viscosity and ends up out of its location. You would have to do a strip down to relocate it every time so it’s worth making sure it stays put.
    I didn’t want to glue the shim in permanently, as I don’t know what the wear rates will be. Experience with the Thorens suggests it will be much slower than for the plastic pad, still the sealant will allow you to change shims if needed. Also remember, the circlip that normally retains the spindle can not be fitted due to lack of access, so you will have to press down on the spindle with your thumb when removing the platter, if you want to keep it in place.



    That’s the bearing completed and filled with 2/3rds “Singer” sowing machine oil and 1/3rd single grade SAE 20 motor oil. The old fashioned stuff (without detergent, anti foaming and dispersal additives) they use on classic cars/bikes. I did a lot of experimenting with oils on the Thorens bearing, proprietary brands and DIY mixes. If the oil is too thin it will spin really well, that is, fast and long but the sonics are not good, harsh and bright. Likewise, too thick and the sound can be dull and smeared. Until I did some tests of my own, if you’d told me the oil in the main bearing can make an audible difference I wouldn’t have believed it. When fitting the spindle don’t over fill it with oil. Apply only light pressure and let it slide in slowly, this may take several minutes. Too much force and the hydraulic pressure may defeat the gasket at the base and cause a leak so take your time. You can always fill the well at the top and let it work its way down over time if it is under filled.

    Because I had a lot of the materials lying around off other projects I haven’t spent much putting this together. I’m using Chemical metal to modify my top plate for instance, but you can buy a tube from Halfords for less than a fiver, I suppose the stainless steel screws and gasket paper came to about £3.80 and the shims were £8 for a set of three. The Brass was £4.70 for a square of each thickness used, I had oil left over from the Thorens. If you had to buy everything from scratch it would cost you around £25, but typically with this type of project, you will have most of the materials left over when finished, as you use only small amounts of everything. The new bearing cost £26, but if yours is ok (Only housing, top bush and spindle required), you could do this mod for about the cost of a new one. If you screw it up you won’t be that much out of pocket, so give it a go. Obviously with this type of bearing cap, you could substitute the steel shim with the bearing material of your choice if you want to experiment. You could even use the stock plastic pad, just use thinner brass sheet for this (The piece with the hole in). If any of you are worried about the strength of the chemical metal, don’t be, with the grooves as keying features it is easily up to the job. You could probably stand on the platter and it wouldn’t give. (Not suggesting you try that) If you want peace of mind you could add side lugs to the cap and make use of the existing screw points to tie everything into the casting but it really isn’t necessary.
    I found a neat trick for marking out the gasket, I drew it on the computer in Corel Draw then printed it onto the 0.4mm gasket paper on my inkjet printer, went through no problem.
    For the full story on this and the rest of my build, see the Technics project on my website, this has a link below.

    So how does it perform?
    I will come back on this, I want to do a shoot out between the stock bearing and this one on my otherwise unmodified 1200 mkII. It will need a bit of running in, 45 RPM for 24 hrs will probably do the trick. Give me a few days to try some back and forth comparisons and I will report back.
    Last edited by Qwin; 15-02-2013 at 17:13.

  5. #25
    Join Date: Jan 2010

    Location: Oxford

    Posts: 872
    I'm NotSoPissedOffNowCosMyHiFisUnpacked.

    Default Can you improve the stock techie bearing???

    That's really interesting. I'm looking forward to your thoughts on the performance. I'll digest and comment later when I can see your pics properly (on my phone at the moment) but that exactly what I had in mind when I started to look at this, just looks like a much better job than I would have made nice idea with the thrust plate using those shims too
    Ian
    http://www.hifisounds.co.uk

    Photo bucket - loads of mods!

    SL1200- DIY PSU- DIY FET int regs-Denon DL103 by Expert Stylus Company on Isokenetic stabiliser & Sumiko HS-12 shell- Achromat - Isonoe feet, Meridian 200 Phono satge, Junson JA-88D, Audio Aero Capitole CD/ DAC, extreme modified Marantz SA7001, Squeezebox Touch modded to death!, Focal 826WSE- Kimber 8TC, Kimber and CAT5 attenuated DIY Interconnects, Kimber mains

    "Leave Nothing as Standard"

  6. #26
    Join Date: Sep 2009

    Location: Essex, UK

    Posts: 3,445
    I'm Andy.

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    Ken, that looks good and am looking forward to your findings- keep up the good work my man!
    System; Michell Gyrodec SE/ Orbe Clamp/ Gert Pedersen armboard mod/ HR PSU/ SME V / J7 Tonearm cable/Ortofon Cadenza Black// Jez Arkless Turbo nutter B------ /Trichord Dino+

    Amplification and loudspeaker set up is at the moment being split into two groups, comprising the following;


    1. Same sources as above; SONY TAF-770ES/SONY CDP761E/Cable Talk 3.1 loudspeakercable/ Harbeth Compact7ES2/ Stands

    2. Virtue Audio Sensation M451battery PSU, ClarityCaps upgrade/ Sensation M901/Russian PIO caps with Teflon bypass caps upgrade/ JT Dynamic PSU with various tweaks/ Connex Audio 5N Litz loudspeaker cable, Impulse H6 Loudspeakers.




















    Me so horny- Impulse H6 Horny

  7. #27
    Join Date: Jan 2010

    Location: Oxford

    Posts: 872
    I'm NotSoPissedOffNowCosMyHiFisUnpacked.

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    Thats mighty impressive Ken!

    I've not doubt whatsoever that the hard thrust plate and oil bath allowing for the use of thinner oil will better the std bearing performance. I was thinking that getting the std bearing to behave like some more conventional bearing with oil baths and utilising a better (harder) thrust plate would be an improvement but what I had in my head was a bit more "heath robinson" than what you've got there.......bloody awesome!!!

    Ian
    http://www.hifisounds.co.uk

    Photo bucket - loads of mods!

    SL1200- DIY PSU- DIY FET int regs-Denon DL103 by Expert Stylus Company on Isokenetic stabiliser & Sumiko HS-12 shell- Achromat - Isonoe feet, Meridian 200 Phono satge, Junson JA-88D, Audio Aero Capitole CD/ DAC, extreme modified Marantz SA7001, Squeezebox Touch modded to death!, Focal 826WSE- Kimber 8TC, Kimber and CAT5 attenuated DIY Interconnects, Kimber mains

    "Leave Nothing as Standard"

  8. #28
    Join Date: Jan 2013

    Location: Carlisle - UK

    Posts: 1,956
    I'm Ken.

    Default Reporting Back on Bearing Shoot Out!

    From a purely frictional point of view the modified bearing offers far less resistance, but only once run in, initially its times were worse than the standard bearing.
    The run down times when switching the power off, were as follows (No record on platter and just a felt mat) Average of three readings.

    Standard Bearing 33RPM = 14.6 sec 45RPM = 19.6 sec

    Modified Initially 33RPM = 7.2 sec 45RPM = 11.5 sec

    Modified Run In 33RPM = 18.6 sec 45RPM = 25.2 sec

    The run in period was only 24 hrs, run at 45RPM, it may improve further.
    I know from experience that thinner oil, eg 100% sowing machine oil will produce longer times but at the expense of the sound, you have to find the right viscosity for the bearing, sympathetic with its design and mounting to get the best acoustic results.

    The strange thing was that although it ran really poorly at first it felt really free compared to the thick dragy feel to the standard bearing with its thick oil, just shows, the feel in your fingers can be deceptive.

    So how does it sound?

    I did four sessions, standard/modified/standard/modified playing the same four complete albums each time. Equipment as in the footer, Techie replaced the ProJect deck, but I still used the Goldring cartridge.

    I will keep it brief, what hit me straight away was the increased warmth and detail of the mid range compared to the standard. Also the treble was not as harsh, being slightly sweeter. Bass is very slightly faster and tighter.

    At the end of the last session I tried putting a pea size piece of Blu Tack under the bearing and tightening it down. When I took it out I had to peel the bearing off the base of the deck, boy did it stick. There is 2mm clearance under the bearing and the 10mm pea had spread to the size of a 10 pence piece. The effect of coupling the bottom of the bearing in this way was a gob smacking bass, without doubt the best I have ever achieved in any of my systems. It was tight fast and owe so deep, real grunt. The down side is that the mid range lost its lifelike feel, it had no bounce or rhythmic feel to it, being dull in comparison. So out it came. When I build the new plinth I will try this again, that bass is something to aim for, but I don’t want it at the expense of the mid range.

    I think for the cost involved in the modification it’s a no brainer, with a significant improvement to the midrange. Tracy Chapman’s voice and guitar were so life like. To improve beyond this you would have to go straight to the Mike New Bearing at ten times the price.

  9. #29
    Join Date: Jan 2010

    Location: Oxford

    Posts: 872
    I'm NotSoPissedOffNowCosMyHiFisUnpacked.

    Default Can you improve the stock techie bearing???

    Sounds extremely interesting!

    Not sure i follow the bit about the blu tak. Where did you put it exactly? Cheers
    Ian
    http://www.hifisounds.co.uk

    Photo bucket - loads of mods!

    SL1200- DIY PSU- DIY FET int regs-Denon DL103 by Expert Stylus Company on Isokenetic stabiliser & Sumiko HS-12 shell- Achromat - Isonoe feet, Meridian 200 Phono satge, Junson JA-88D, Audio Aero Capitole CD/ DAC, extreme modified Marantz SA7001, Squeezebox Touch modded to death!, Focal 826WSE- Kimber 8TC, Kimber and CAT5 attenuated DIY Interconnects, Kimber mains

    "Leave Nothing as Standard"

  10. #30
    synsei Guest

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    Ken, instead of BluTack try a plug of Sorbothane

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