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Manticore Mantra repairs

Discussion in 'd.i.y.' started by cj66, Aug 18, 2022.

  1. Craig B

    Craig B Re:trophile

    I always use the direct link (2nd from top in the provided links) and then paste this into the image dialog box on here. Works every time.
     
    a.palfreyman likes this.
  2. Rob88

    Rob88 pfm Member

    I myself have a Manticore. It runs pretty silent and very well.

    However I would like to oil the motor bearing as I’m not sure when it has been done the last time.

    Very silly question (never done it before) but where do you put the oil? I can’t see any hole, and I can’t remove the pulley. By underneath then?

    Also, what difference does the blue belt compared to the Thorens that fit the Mantra?

    many thanks
     
  3. Craig B

    Craig B Re:trophile

    The procedure is to place a single drop at the base of the motor spindle where it exits the motor housing beneath the pulley. It can help to use an unfolded paper clip, or even a toothpick here, as a sufficiently sized drop is exactly how much will cling onto such just long enough to get it in under the pulley and onto the motor spindle. Singer oil is perfectly adequate here. The motor bearings* are actually sintered bronze sleeves which are factory impregnated with oil, the single drop helps to reactivate this as well as to wash away accumulated gunk that may plug the pores within these sleeves. Best to let the motor sit for a while post oiling in order to let the lubrication seep in (although it doesn't hurt to manually rotate the pulley back and forth a bit post placing the drop).

    * Bearings plural, as there are actually two, one top and one bottom. Your Manticore will have come with an added thrust bearing supporting the bottom end of the motor spindle (keeps the moving parts 'afloat' within) which should be left undisturbed (i.e. no oiling) unless the motor were mechanically noisy and oiling the top bearing only didn't solve anything, and/or there is stiction which indicates that a full bearing flush and re-oiling, both top and bottom, are warranted. You'll notice a number of photos of this thrust bearing cap back on page 1. This would need be removed in order to oil the bottom bearing sleeve.
     
    Last edited: Sep 28, 2022
    Rob88 likes this.
  4. cj66

    cj66 pfm Member

    Exactly as @Craig B has said.

    In my case the pulley came off very easily making the oiling straight forward.

    As for the difference between the belts I have no idea, the old Thorens belt was already too far gone. To my knowledge these are no longer available.
    I initially chanced an eBay belt but it proved to be way off the mark. The blue one is doing it's job as it should.
    There are two other threads about these belts, one general and the other specifically for the LP12, where comparisons are made.

    I found the https://pinkfishmedia.net/forum/threads/lp12-blue-belt.270484/
    LP12 thread...

    ...and the other one https://pinkfishmedia.net/forum/threads/today-i-am-a-small-blue-thing.265660/
     
    Rob88 likes this.
  5. Rob88

    Rob88 pfm Member

    Perfect, thanks a lot for your answer.

    I was actually assuming that it was the only way to oil it, but it just didn’t look right to me. Some rega pulley for exemple have a hole at the top. That makes things easier.

    Anyway it is done, it wasn’t easy to get a drop in there without it to go on the plinth or the pulley itself.

    As for the belt, I may give a try to one of these blue belt. Mine is branded Thorens, which means it has been changed at some point in the TT life but I don’t know how old it is so it can’t do any harm to change it. It’s the same than the TD150, is that right?

    thanks
     
    Craig B likes this.
  6. Mike P

    Mike P Trade: Pickwell Audio

    @cj66 sent me some measurements taken from his deck and based on those measurements we decided to go with a slightly smaller diameter belt to the one I supply for the Thorens TD150/TD160 etc. He reckons that it fits well.
     
    Rob88 likes this.
  7. Craig B

    Craig B Re:trophile

    Glad to hear that you managed to get a drop in there.

    Just as an FYI, and for the benefit of others attempting same, a drop of oil into the hole at the top of any pulley isn't likely to make it down into the motor bearing sleeve. In the photo below you'll notice the top edge of the bronze bearing sleeve encircling the spindle. This is where you want to directly place the drop of lubricant.

    [​IMG]
     
    Last edited: Sep 29, 2022
  8. Rob88

    Rob88 pfm Member

    In a way I wish I could have removed the pulley to ensure I did add the right amount. I have to say it was a bit hazardous. But as the pulley was well in place, it didn’t force.

    as for the under plater spindle, I’ve added 3 drops of the same oil. It spins perfect. I wasn’t sure if it had to be oiled like the LP12 spindle but from what I understand when reading the manual, 3 drops are enough (?)
     
  9. Craig B

    Craig B Re:trophile

    The three drops should be of Hypoid 80 (or 80W/90) gear oil. These are added post a thorough cleaning of all of the old oil residue from the bearing well, ball and sub-platter spindle using meths.

    With this, the Rega, and certain other similar straight shaft sintered bearing sleeve designs, the gear oil is part and parcel of there being near zero tolerance when driven. Three drops might seem an insufficient amount, that is, until one subtracts the area of the ball from the area that the ball sits within, that which ends up between spindle shaft and sleeve is infinitesimal. Contrast these with upper and lower polymer ring sleeved bearings like the Linn, and it becomes obvious why more oil is required with those. In fact, the Linn is more critical of oil 'level' as neither the polymer sleeves nor any metal parts that the spindle contacts retain oil, whereas sintered bronze wells and sleeves are like metal sponges.
     
    Rob88 likes this.
  10. Rob88

    Rob88 pfm Member

    Very helpful and instructive, thank you.
    But hold on, what do you mean by ball? Is there one at the bottom of the well?

    I have cleaned the well and the spindle with IPA, but I didn’t notice a ball inside. Maybe I should put the TT upside down for it to fall. Something I do not like to do.

    As for the oil, the only one I have on hand is some wahl clipper oil, I’ll order what you recommend if this isn’t good.
     
  11. Craig B

    Craig B Re:trophile

    Yes, the bottom end of the platter spindle is flat and sits upon a ball bearing. Rather than turn the deck upside down, you could try using a drinking straw and apply some suction. :)

    The Wahl clipper oil is far too light. Castrol Hypoy C is widely available, your local automotive garage might even give you a thimble full FOC. The usual 946ml bottle is enough to do 6,306 turntable oil changes (based upon 1ml = 20 drops). Of course, one could fill an eye dropper bottle and throw the rest into one's car or truck differential. Or, pick up 1000 eye dropper bottles, half fill them, and sell all via eBay as Miracle Turntable Oil at 20 quid a pop plus shipping.

    [​IMG]
     
    Last edited: Sep 29, 2022
    Rob88 likes this.
  12. Mike P

    Mike P Trade: Pickwell Audio

    I would advise caution regarding the use of gear oils in turntables that use sintered bronze bearings.

    Gear oils usually contain sulphur compounds (EP additives) that are corrosive to yellow metals.

    This is a well understood issue and standardised tests exist for determining how 'yellow metal safe' gear oils are. Google 'ASTM D130-10 copper strip test'.

    For most turntables a circulating oil of around ISO 46 to ISO 68 (approximately SAE crankcase 20-30) is about right and a safe choice.
     
    Last edited: Sep 29, 2022
    Rob88 and a.palfreyman like this.
  13. a.palfreyman

    a.palfreyman pfm Member

    Yes, I believe Marc Morin (specialised in AR tables, now sadly RIP) indicated light oil, SAE 20 or thereabouts. Heavy oils produce more bearing noise/rumble.
     
  14. Rob88

    Rob88 pfm Member

    Thank you. I’ll have to find a way to get a small quantity of oil as I don’t want to have a 1l bottle of motor oil in my closet while I’ll only use a few drops. However forget to automotive garage near me, in central London I probably never saw one. I don’t even have a car in fact.
    Thanks for the info
     
  15. Craig B

    Craig B Re:trophile

    With all due respect to the late Mr. Morin, I don't buy into the 'more bearing noise/rumble' bit at all. We are not talking treacle here, just squirt a drop of 80W/90 on a finger and give it a rub, smooth as silk. In fact, gear oils are designed to exhibit lower friction combined with higher pressure resistance, as metal to metal contact is even more of a concern with transmissions and differentials.

    AR specified #10 oil, particularly Golden Shell 10W. I suspect that they were erring on the safe side, what with the notorious swelling of the ill-fated Delrin sleeves early on. They also specified adding three drops once per year.

    Getting back to gear oils, a proffered advantage of using these in turntable bearings is that they virtually eliminate bearing 'slop', i.e. bearing precession, a result of there being no chance of having zero tolerance between spindle and sleeve (else these parts seize). Spindle, plus gear oil, plus sleeve equates to zero tolerance when driven. Rega, Systemdek, Manticore, etc. are unlikely to have all been wrong wrt this aspect of turntable bearings; especially so, Rega, what with Roy Gandy having been an engineer at Ford.

    IME, SAE 20 or 30 work well, however, according to the lubricant makers, neither have the same ability as gear oils to both adhere to metals and resist pressure, and therefore prevent metal on metal contact, especially so when being driven by being pulled to one side at a right angle to the bearings axis of rotation. As with automobile engines, it is during cold starts that most metal on metal contact occurs, another reason to leave one's record deck running during an entire listening session (not to mention another reason to use 'sticky' gear oils).
     
  16. Mike P

    Mike P Trade: Pickwell Audio

    Method : ASTM D130 The copper strip corrosion test is designed to assess the relative degree of corrosivity of a petroleum product due to active sulfur compounds. The Copper Corrosion test is a widely used oil analysis method for gearbox, turbine and hydraulic lubricants. This oil analysis method will detect the corrosive effects of a lubricant on copper alloys, but it is ineffective on iron or ferrous alloy parts and components. The copper corrosion oil analysis method, ASTM D130, is relatively simple. A polished copper strip is immersed in 30mL of sample at elevated temperature, 50 °C or 100° C, depending on the type of gasoline, grease or oil tested, for a period of three hours. At the end of this period, the copper strip is cleaned and examined for evidence of degradation. Results are rated by comparing the stains on the copper strip to the ASTM color-match scale from 1A to 4C. The rating of 1A is given for appearance of freshly polished copper coupons with slight discoloration, but barely noticeable; 1B indicates slight tarnish, and the ratings proceed further down the scale as corrosion staining of the test coupon increases, with 4C being the worst, typically appearing as severely corroded, blackened, and pitted coupon. ASTM Method D130 covers the determination of the corrosiveness to copper of aviation gasoline, aviation turbine fuel, automotive gasoline, cleaners (Stoddard) solvents, kerosene, diesel fuel, distillate fuel oil, lubricating oil, and natural gasoline or other hydrocarbons having a vapor pressure no greater than 124 kPa (18 psi) at 37.8°C.

    If you insist on using a gear oil in a turntable with a sintered bronze bushing it pays to check the copper strip test result of the oil you're thinking about using.

    Edit: I looked up the copper strip test result for Castrol Hypoy C and it gets a 1B rating, so as gear oils go it's pretty benign to yellow metals. Other gears oils may be much more damaging. You've been warned folks.
     
    Craig B likes this.
  17. Craig B

    Craig B Re:trophile

    Noted. In fact, I do recall reading that exact text someplace.

    Then again, I've have a couple of Rega decks here that have had gear oil in them since the 1970s. All still nice a shiny down the sleeve and across the bottom; not that the bottom matters as much, as the spindle pirouettes atop the ball. Not that this is related to the affects of sulphur compounds, however, one of these decks, a Planar 3/R200, had been allowed to run dry for many years, as the original owner enjoyed pulling the hub/spindle out and showing how nicely made it was to visitors (he did so for me when I went round to look at the deck, and it was as dry as a bone). Although the bottom of the spindle has almost been converted into a captive ball design (not really, but boy what a dimple), with the ball looking at bit like a wee black and white soccer ball, the spindle shaft appears perfect with a lovely mirror finish (note the perfectly straight reflections of the radial ribs of the hub in the first photo below). Regardless, a thorough cleaning and three drops of 80W/90 later and it sounded superb. I've since landed a less abused bearing spindle and ball from a P3 2000 (via a local Planar bodger for $15!) and all feels better now.

    Original Planar 3 (R200 era) spindle after having been run dry for some years (decades?):
    [​IMG]

    P3 2000 bearing, obviously pushed down hard a few times but otherwise reasonable wear for age:
    [​IMG]
     
  18. Craig B

    Craig B Re:trophile

    It would be interesting to know the copper strip test results for Rega's old recommended list of bearing lubes. The only problem with this is that these vendors appear to have changed their offerings since. The Rega service recommendations were as follows:
    • Comma Hypoid EP80
    • Castrol EPX80w/90
    • Shell Spirax EP90
    Found this on one of the major lubricant makers sites:

    The main difference between GL-4 and GL-5 gear oils is the amount of EP additives. Sulphur/Phosphorus containing products are used as EP-additive. This additive has the purpose to prevent the occurrence of micro-welds on the gear flanks at the local high temperatures which prevail in EP circumstances (temperatures well in excess of 800℃!) GL-5 has roughly twice the amount of EP additives compared to GL-4, which is why it is often used in high-pressure circumstances such as in a front axle and rear axle differential.

    Sulphur/Phosphorus additives however have an unfavourable property: they can react aggressively towards bronze and copper. This can be disastrous for the synchromesh rings of a gearbox. Therefore it is not recommended to use GL-5 in a gearbox unless the manufacturer allows this.

    To conclude:

    • GL-4 is suitable for hypoid gear service when they are under severe service but are without shock loading.
    • GL-5 is suitable for hypoid gear service under severe service and shock loads and not for use in a gearbox.
    The definitive reference for API lubricant ratings is https://www.api.org/-/media/Files/C...blications/1560-Eighth-Edition-April-2013.pdf

    Getting back to Rega's old recommendations, Comma brand Hypoid EP80W-90 is available in both GL-4 and GL-5. Castrol's current lineup is quite varied with many offerings being to GL-5 (especially so, anything with the words, 'axle', 'transaxle' etc in the name), although they do have some described as 'universal' and claiming to suit both GL-4 or GL-5 requirements. My Castrol Hypoy C above, appears to be MIA, however a link to the date sheet is included below. This is rated GL-5 but is recommended for use in manual transmissions (part of the reason why I purchased this). Shell Spirax EP90 no longer appears to be an offering, however, Shell Spirax S2 G 80W-90 is rated GL-4 and recommended for both manual transmissions and gear sets.
     
  19. Craig B

    Craig B Re:trophile

    WRT a Castrol replacement for their Hypoy C, their stockists appear to be substituting this. Be warned that this is not recommended for use in manual transmissions and therefore is likely to have a high phosphorus content.

    [​IMG]
     
  20. fatcat

    fatcat pfm Member

    The ball won’t come out; it’s been pressed onto bearing hole. The ball burnishes the bearing hole, producing a very smooth finish.

    Manticore instructions advise that hypoid 80 should be used. In fact they supply a small vial containing hypoid 80, for topping up the bearing.
     
    Rob88 likes this.

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