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  »  New  The Foolishness of Analog People..  Late to the discussion but cannot resist...  Analog Playback Forum     56  585125  01-30-2006
  »  New  Micro RX 5000..  Alternative method...  Analog Playback Forum     9  69935  11-09-2008
  »  New  Micro RX5000: is that bearing spins normally?..  How many turns do the good bearing......  Analog Playback Forum     7  42886  02-03-2014
  »  New  Fetish of Micro's?..  Size of ceramic ball...  Analog Playback Forum     122  414513  10-29-2017
01-23-2016 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006
Post #: 26
Post ID: 22416
Reply to: 22415
Rube Goldberg in Drag
fiogf49gjkf0d
This is interesting. Of course the last word is always net "sonic gains", whatever they are deemed to be. When I look at this I wonder if similar results might be gotten by applying measured "drag" to the platter/motor, like Spiral Groove (and a few others, I think) do it. And, in the end, given the relationship between the platter, the motor, the thread and the "flywheel", I wonder how this is so different from simply using a less powerful motor with the original TT, or using two or three motors, etc.? What is the "explanation"?

Best regards,
Paul S
01-23-2016 Post does not mapped to Knowledge Tree
Retrofunk
Dallas Via London
Posts 6
Joined on 01-23-2016
Post #: 27
Post ID: 22417
Reply to: 22416
Drag
fiogf49gjkf0d
Paul S, you raise a good point, throughout this whole process - in the back of my mind - I have been thinking surely, less drag, less torque, the motor not working as hard would be optimum. Using a roadrunner tach to report the RPM to 3 digits, currently the single motor option is more accurate. I am sure i can get the motor and flywheel to the same accuracy, but adding another variable just makes the 'tweaking' more time consuming. 

Micro Seiki RX5000 handmade clone (double stacked), Micro Seiki Flywheel, Fidelity Research FR 64S, SME3009 S3, DynAudio C1, Merrill Audio Thor MonoBlocks, VAC Signature MKII, Keith Monk RCM, Denon Au 320 SUT, Technics SL1200 (KABUSA) Marantz 2330b
01-23-2016 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006
Post #: 28
Post ID: 22418
Reply to: 22417
Speed accuracy
fiogf49gjkf0d
It seems like you are saying that so loading the motor somehow makes it more accurate, so it sounds better. Is this the case? I thought the "most accurate" speed control was DD with a servo (that only "corrects" errors after the fact), as "measured" by a device that is slower than the correction circuit? I am trying, but I can't understand how the flywheel should help more than just dialing in the basic set-up, in light of the weight of that platter assembly, going in. Doesn't there "have to be" an "optimal" relationship between a particular motor and such a giant platter that it would obviate the extra "flywheel"? Perhaps it is just "too much motor", going in? Again, how do the promoters "justify" the device?


Best regards,
Paul S
01-23-2016 Post does not mapped to Knowledge Tree
Retrofunk
Dallas Via London
Posts 6
Joined on 01-23-2016
Post #: 29
Post ID: 22419
Reply to: 22418
Speed
fiogf49gjkf0d
actually I was saying the contrary should ideally be optimum, less is more. My experience so far is that the single motor works under less strain and provides a more accurate speed - as measured on may Roadrunner Tach. However, having shelled out for an expensive flywheel , I am going to continue to tweak its position and that of the motor to see if i can obtain as an accurate speed as the single motor. If starting from scratch and knowing what I know now, in hindsight I would likely just stick with the single motor and would not have ventured down the path of exploring the flywheel. Again, this is just my 2c, quite  a few people swear the addition of the flywheel adds something better, than without.


Micro Seiki RX5000 handmade clone (double stacked), Micro Seiki Flywheel, Fidelity Research FR 64S, SME3009 S3, DynAudio C1, Merrill Audio Thor MonoBlocks, VAC Signature MKII, Keith Monk RCM, Denon Au 320 SUT, Technics SL1200 (KABUSA) Marantz 2330b
01-23-2016 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006
Post #: 30
Post ID: 22420
Reply to: 22419
Still Dying
fiogf49gjkf0d
to hear the "explanation". In the meantime, I would think you'd want to thoroughly optimize the system without the flywheel first, in order to establish a base line, then add the flywheel, all while keeping the isolated idea of "speed control" in perspective, of course. From what little you've said so far, it sounds like the guy who sticks a strong driver into a big horn then notes that "LF is more extended". As for the people who "swear" by the flywheel, I hope one or more of them will chime in with a coherent take. On other forums, mere mention of the MS TTs is like a drug, and their putative presence alone inspires slack-jawed reverence. Not so here, however, despite the Boss owns them, himself.

If it makes you feel any better, truth be told, I'm sure I have "wasted" a lot more than I've spent well playing with hi-fi.


Best regards,
Paul S
01-30-2016 Post does not mapped to Knowledge Tree
chaslieb
Posts 4
Joined on 01-30-2016
Post #: 31
Post ID: 22446
Reply to: 22419
From a physics perspective...
fiogf49gjkf0d
I don't understand why people are using the flywheel with the same thread coming off the motor to go around both the turntable platter and the flywheel.  I also don't get why the flywheel is supposed to be used with a slipping thread at all.  To make it simpler, if we look at the transmission of energy from the motor unit to the turntable platter like filling a bucket with water, the motor's goal is to keep the platter spinning at the same rate, which would in our terms mean keeping the water level the same in the bucket.  The drag of the bearing, drag of the stylus and friction of the thread or belt are all reducing the amount of energy stored by the rotating platter.  We can think of them as holes in the bucket.  

The thread used to transmit energy is designed to slip on the platter.  This clearly protects the motor from burning out, but also prevents speed variations in the motor from having an effect on the speed of the platter.  If there is a slight increase or decrease in speed, the thread will slip and not transmit these micro variations to the platter.  The same slippage which serves a purpose for a motor to platter, makes the thread a useless device to couple a flywheel to the turntable platter.  If we go back to the water example, a flywheel adds energy storage and should make our bucket larger so that the small holes draining energy, by the bearing or by the stylus drag, have even less effect on the water level.  In practice, the use of a thread to couple the flywheel to the turntable platter is like a small pipe attaching two buckets of water.  When the water level in one goes down it will take time for the other to level it off because the transmission of energy, like the transmission of water between the buckets is not instantaneous.  This can create an oscillation between the transmission and response between the motor, platter and flywheel and could be predicted to create speed instability.  This situation is worse than having no flywheel at all!  A solid coupling of energy, like simply stacking platters or an idler wheel between the platter and flywheel will ensure a tight coupling and instantaneous transmission of energy, like making a bigger bucket.  If a belt is to be used between the platter and flywheel, it must be a rigid belt, meaning that it will not stretch or contract.  Rubber is useless for this purpose.  It also must grip both the platter and flywheel and therefore a coating that gives it  such grip to avoid slippage is necessary.  from what items are out there, only a non stretching fabric or plastic belt with some sort of gripping coating should be considered.  Given the different job to be accomplished by the thread drive from the motor, which is meant to slip, and the tight coupling needed to make a flywheel effective it is amazing to see people who set up their turntables the exact opposite way; with the thread connecting the flywheel to the platter and the belt between the motor and platter.  Probably just as bad are those who use a single thread to connect the motor, turntable and flywheel.  

Looking at the microseiki.nl site I see that they say their flywheel should only be used with a thread.  Considering the implications based on the coupling issues, I cannot guess why.  Also, I see people say that the flywheel was meant to augment the air bearing and not the oil bearing.  Given that the air bearing should have less friction losses than the oil bearing, I don't understand this either.  It seems like the greatest benefit would not be to the air bearing which already has the advantage of less friction, but to the oil bearing that has more friction losses and therefore more to gain by added energy storage.  I have not heard the flywheel used with thread or belt in any system and this analysis is solely scientific, and has nothing to do with anyone's personal experience in their system.  However, in my way of thinking, math helps explain the subjective phenomena we perceive, so I put these thoughts out there to suggest a possible way to approach the use of the flywheel that may provide a benefit.
Charles
02-02-2016 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,159
Joined on 05-28-2004
Post #: 32
Post ID: 22454
Reply to: 22446
...generally is not wrong but...
fiogf49gjkf0d
Chaslieb, you generally is not wrong BUT all of those very rational theories have in my view any practical meaning only in context of TTs with conventional platters, means the platters of sane mass. As soon we enter of domain the platters let say over 70-100 pounds then any exterior torque forces, acute pulling from belt or anything else external influences become just irrelevant. Retrofunk admits that visual aspect of the flywheel is very attractive and no one denies it. He also confirms what I have been advocating for years: with heavy platter there is no sonic impact to sound. I did not use a flywheel but I used an additional platter of Micro 5000 as a flywheel. I used a reel-to-reel tape to run the platter that is ultimate slipping drive.
 
http://www.goodsoundclub.com/Playback/Site_images/MicroDual1.jpg 
 
I do not feel that there was any tangible sonic impact from the second platter. 
 
One more thing. We all for sure would like to have our platters to have a stable rotation. Now is the question: what deviation from the stability we do hear. If the platter goes on and off 0.1rotation per minute them is it auditable? Let me to rephrase it. If a platter has a stable constant deviation from 33.33, or whatever it shall be then how auditable is it?  If it does 32.1RPM then what do we hear? Download the brilliant RPM app to your smart phone and play with it. Yes, we feel a change in pitch but where it become practically significant? This is the questions that everyone should answer to themselves. 
 
Still, I would insist that majority of audio people out there who love to be proud that they spent a lot of money  for super-duper solutions to stabilized the speed have still no clue what they are taking. A case to proof my arrogance. Year back, I think it was 2006, the last year I went to CES, the Australian company Continuum was just a start up. They brought a first model of their TT and it was before they become “famous” and before a few US marketing whores puffed them up.  So, Continuum, facilitated a closed demo at night for industry folks, trying to win US distribution rights. The room was staffed with all possible reviewers, distributes, dealers, editors and I was looking at all of that collection of audio dirt and was envying to those Muslims suicide bombers… Anyhow, the Continuum guy was spinning Heifetz’s Bach partitas. After the very first notes that were way lower I was looking at a friend of my (who invited me to that session) and asking with my eye if it was for real. He was also look like he had a tooth pain. The rest of the industry Morons were siting there listening that crap with no apparent complain or reaction. I stopped the listening and informed that the platter speed is way off. The Continuum guy did not believe me (!!!) and insisted that it need to be measured (!!!). So, he did and of cause it was way slower. It is not a big deal the TT get broken. However, that image of that room filled up with all that golden-ears holders audio-writing idiots,  sitting there, looking at that turntable, listening the objectively faulty sound and having to brain to recognize what they are hearing is very much follow me each time I see them writing anything about analog sound reproduction. Well, whatever it worth the Continuum did what they wanted. At the show they were selling the TT for $10-15K with target retail price of $25-$30 but a few month after the show and after the Framer and the rest dirt engage the Continuum the price went to $150K or something like this. BTW, my satiate about the Continuum  was written in a memory of that event: 
 
http://www.goodsoundclub.com/Forums/ShowPost.aspx?PostID=1957  
 
The Cat
 

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
02-02-2016 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,658
Joined on 10-12-2006
Post #: 33
Post ID: 22455
Reply to: 22454
Rationale
fiogf49gjkf0d
How many decent hi-fi "demonstrations" have I heard? Not many, that's for sure, and it does seem like the more expensive the gear, and the more arcane and/or elaborate the "case" for the equipment, the bigger the problems when that gear is demonstrated. The endless double-talk seems to be enough for many, in and of itself, and some literally buy in to the prattle. Of those, some "communicate" with each other in a proscribed language that avoids the methodology and/or topics that would be relevant in order to actually try to make the best of the product in question. For some, it becomes a matter of "keeping up" with the latest tweak. In most cases, pride of ownership is literally advertised and worn like a badge of honor and/or entitlement. Like Forrest Gump's mother always told him, "Stupid is as stupid does." I don't give a shit how much mass a TT has if the guy who uses it is unmindful of it's audio potential in terms of advanced audio, and IMO this condition is only worsened if the guy is also unconcerned or otherwise totally distracted by background noise.


Paul S
02-02-2016 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 34
Post ID: 22456
Reply to: 22446
Slippage?
fiogf49gjkf0d
On the topic of string slippage: I don't think my string, the original one from MS by the way, slips at all once the platter is up to speed. It would slip on the motor pulley when first turned on, as the heavy platter must be gradually brought up to speed, unless you give the platter a spin by hand before turning on power, as I do. Once up to speed, "stiction" (static friction) holds the string in place on the pulley and the platter. This is easy to verify on the platter side because you can watch the platter and string up close and see that they are moving together. It harder to see what's happening on the pulley side, so I ran a test. In the course of rebuilding my motor electronics (mostly replacing all electrolytic caps preventively), I monitored voltages inside the complex drive electronics while putting the table through its paces. The tachometer provides feedback to an error amplifier and then to series-pass power transistor emitter followers that drive the motor windings. I put an oscilloscope probe on those points (and others) while varying the load on the motor. As expected, when the motor encounters more friction, the voltage jumps up to compensate, keeping speed constant. It's a very sensitive system. I watched this voltage on the scope while gently touching the platter. The voltage responded immediately. Even the tiniest touches on the rotating platter, that I dare say nobody would hear as pitch changes, were responded to, immediately. If the string were slipping, this response would not be so immediate nor so proportional. I ran another test. I adjusted the motor speed control to give a platter speed of exactly 33 1/3 rpm using a stroboscope, at my average string tension setting. I then watched the stroboscope as I slightly varied the string tension by pressing a shiny screwdriver shaft against the moving string midway between motor and platter. I also very slightly nudged the RY-5500 motor closer to, and then farther from the platter while monitoring the stroboscope. The speed remained constant. If the string were slipping, the motor's tachometer would not "know" what the platter's speed was and it wouldn't be able to correct it. Tiny friction changes and speed variations caused by motor cogging, stylus drag and external vibrations are simply not enough to break the stiction bond between the string and the motor pulley or the platter, as long as the string tension is properly set over a wide set of tensions. Slippage would make no engineering sense that I can see. It would make speed setting uncertain, and it would result in scraping noise as the stiction is overcome (like a violin bow scrapes on the strings). Plus it would cause excessive wear on the string and pulley! My Kevlar string is probably close to 40 years old and it looks almost new.
Of course there are many ways to set up this turntable and its string. Then most critical factor is string tension. The string has a tensile strength of 24.5kg (54 pounds), so that there is a wide range of string tensions possible between total slippage and the string breaking. MS had little to say about it in the RX-5000 manual. I've set my string's tension so that there is about a half-inch of deflection midway between motor and platter with a light sideways touch of the finger. Not very scientific, but it works. It's not so tight that it's putting a significant side load on the bearings, nor is it so loose that there is any slippage once the system is up to speed. Like many things with this amazing table, it is probably not very critical over a broad range.
Here is what MS had to say:

* Positioning the string>>

First, the installation location of the platter unit is determined and the unit is secured. The motor unit is then provisionally placed between 10 and 15 cm away. The string is then cut to a length enabling it to pass outside the pulley and the platter perimeter, and bound firmly. The end of the string projecting from the join is then cut off with scissors. After checking that the string has been positioned around the platter and pulley, the motor unit is gradually moved out and the string pulled taut. Make sure that you do not make the string too tight. Once the platter rotates, the inertia will have an effect and so there is no need for the string to be pulled too tight because the power is transmitted. However, if the platter is helped to rotate by hand when it first starts up, it will reach the rated speed smoothly.>>



______________
Brian
02-03-2016 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 10,159
Joined on 05-28-2004
Post #: 35
Post ID: 22457
Reply to: 22456
That is pretty much what I am saying.
fiogf49gjkf0d
Yes, Wellington, that is pretty much what I am saying: if a TT have heavy enough platter and the bearing done right then the any speed deviations of motor of belt are kind of irrelevant. I remember years back a Russian guy presented heavy mathematics to model TT interfaces. It was hard belt, loos belt, idle wheel, direct drive. He was trying to prove from mathematical model perspective that one interface is better than another. Interesting that all his calculations according to him make any sense only in context of TT with platters mass comparable to the driving force.  He insisted that if platter mass and the consequential moment of inertia is too large then there is negligible difference how the platter is driven. I do not insist that he is right but to me his theory completely makes sense.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
02-03-2016 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 36
Post ID: 22458
Reply to: 22457
Diminishing Returns
fiogf49gjkf0d
Yes, the Law of Diminishing Returns must apply to platter inertia, as it does for so many other things.

______________
Brian
07-22-2017 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 37
Post ID: 23335
Reply to: 22458
One more thing...
Anyone contemplating buying a CU-180 should know that it must be dead flat. Even the slightest departure from being flat will negate the benefit of intimate contact across the entire surface of the platter.

How flat? Flat enough that the weight of the CU-180 alone is sufficient to overcome the normal microscopic deviations from perfect flatness in both the platter and CU-180. In other words any minute departures from perfect flatness caused by machining, too small to see, will be overcome by the draping flexure caused by its own weight.

How can I test for this? Two ways. Visibly sighting is not enough. If it is visibly bent it is already an expensive (and deadly) Frisbee. Put the CU-180 on the platter without a record and tap all around the playing surface region with finger tips or knuckles. Check around the whole circumference. Rotate the CU-180 relative to the platter in increments and tap again. Try the rotation around all 360 degrees. You should feel and hear a "granite mountain" at all times. If you hear any tapping or clicking sound or buzzing, any at all, the CU-180 is slightly bent. Reject it. I am assuming the use of a massive Micro Seiki platter here, and assuming that that platter is flat, which it will be unless it was dropped. Another test is to lay the CU-180 onto a heavy glass table or a granite countertop used as a truly flat reference plane. Try to see/hear if there is even the slightlest play. Repeat the tap test.

What could cause a non-flat CU-180? Being dropped, just once, even onto a carpeted floor. Or getting flexed in shipping with inadequate packing.

Can't I just bend it back? No. At least almost certainly not. Once bent it will be hard to get it back into true flatness and small voids will occur from stresses remaining in the alloy. Think of unfolding a paper clip into a "straight" wire. How straight is it? No amount of fidgeting with it can ever make it truly straight again.

Buying? I have seen a few CU-180s for sale that say "slightly bent". A 1% bend does not decrease value by only 1%; it decreases value by 100%. Think paper weight. Get assurances that a return is allowed.

But a vinyl record is never perfectly flat. True of course, but we have to get the interface, the constrained layer, between the platter and CU-180 correct first. Then we can use a record weight or clamp to mash the record flat (as flat as possible) directly onto the clean CU-180.

Isn't this a pain in the ass? Yes, it is. But if you want to hear what your Micro Seiki is truly capable of, it's worth seeking out a flat CU-180.




______________
Brian
07-23-2017 Post does not mapped to Knowledge Tree
N-set
Gdansk, Poland
Posts 617
Joined on 01-07-2006
Post #: 38
Post ID: 23336
Reply to: 23335
Why buying this at all?
Not a MS owner, but have been wondering why buying this 30+ yrs old mat at all with all the risks you describe?
Virtually any modern metal shop will be able to machine it and check the flatness down to microns. The price I guess would also be much lower than a "vintage" one. Just a thought.



Cheers,
Jarek
STACORE
07-23-2017 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 39
Post ID: 23337
Reply to: 23336
And I'm not trying to sell it!
It is entirely possible to buy a good flat CU-180. I have two from eBay there were correctly advertised as being flat. I have also seen them on eBay as being "slightly bent". Those you avoid.
But I agree that a replica is a real possibility. I never said that the CU-180 is the only possibility. It is the only one with which I can confidently report excellent results. In fact I have seen copper mat replicas on eBay. If an experienced machinist properly machines both sides, and expertly handles any annealing and post handling, a good flat "copper" mat should be the outcome. There is the question of duplicating the alloy of the original CU-180 mat. How much does that matter? I don't know.
Micro Seiki also made the heavier CU-500 mat which is quite rare now. I have not used one. There was another vintage manufacturer of copper mats. The name escapes me, but I want to say "Final Sounds."(?) I also recall seeing at least one recent manufacturer, mainly appealing to the Technics crowd who love the CU-180.

______________
Brian
08-23-2017 Post does not mapped to Knowledge Tree
measet
Posts 15
Joined on 08-15-2017
Post #: 40
Post ID: 23365
Reply to: 22028
Stainless steel platter for Micro RX-5000
Hi Wellington,


Also I'm thinking to make a stainless steel platter for my RX-5000.
As you have good experience with yours could you tell me the exact parameters of the new design (beveled insight edge, thicker deck part). The schematic would be the best.
I was looking for the 316L material, I found the needed diameter but all of them have a very small reaction to magnet what I think is slightly unfortunate close to the cartridge area. Have you experience with this isue?

Thanks a lot!
08-23-2017 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 41
Post ID: 23366
Reply to: 23365
316L magnetism and platter drawing
Measet,
As you may know, 316L is a low-carbon austenitic stainless steel which has superior corrosion as well as machining and welding properties. It is generally non-magnetic in the raw state, but cold working can convert tiny amounts of its austenite to martensite, which is slightly magnetic.
I checked my platter again today with a small but very powerful neodymium magnet. It does barely attract to the platter, but far, far less than to regular steel. I can no longer feel any pull at all with the copper CU-180 mat on top of the platter, separating the magnet from the platter. I do not worry about it.
Ironically (and that's a pun as you will see), this magnet pulls stronger to the black speckled granite slabs that my RX-5000 sit on. Yep, there must be iron flakes inside the granite, and these attract the magnet more than a 50-pound chunk of 316L!
I will try try to attach a drawing of my platter design. The drawing assumes you know or can measure the other dimensions of the original platter. The angled underside surface reduces the bell-like ringing mode of the original design, as well as increasing mass.


______________
Brian
08-23-2017 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 42
Post ID: 23367
Reply to: 23366
No PDFs allowed
Ok, so Romy doesn't allow posting a PDF file. Let me try to make a JPG out of it...

______________
Brian
08-23-2017 Post does not mapped to Knowledge Tree
measet
Posts 15
Joined on 08-15-2017
Post #: 43
Post ID: 23368
Reply to: 23367
Stainless steel platter for Micro RX-5000
Hi Brian,

Thanks for useful infos.
Recently I had possibility to enter in to supplier warehouse to check how the magnet react on different ss materials.
I found some types which attracted the magnet still less than 316L. I'm not an expert in metallurgy, also I do not know what is the main preference of ss material for a good turntable platter. What do you think is it worth to choose other material or 316L is good enough.
I see you use the heavy weight ss platter from years, could you confirm that the bearing performing well and resist to higher mass?

Thanks a lot!
08-23-2017 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 44
Post ID: 23369
Reply to: 23368
Magnetic attraction
While my background is in engineering, I am not a metallurgist either. But I do know that 316L is considered an non-magnetic material (see https://greenwoodmagnetics.com/resource/what-is-the-difference-between-304-and-316-stainless-steel/). But even these non-magnetic grades can be made very slightly magnetic by cold working: rolling, peening, and even machining. You could anneal the work after machining, but then you'd get surface discoloration, and possibly warping as stresses are relieved. You could anneal the blank material first, and then you'd only have small work hardening from the surface machining. There is no telling what working processes your samples in the warehouse were exposed to.
TechDas, Micro Seiki's successor, uses 316L in the platters of its mighty Air Force tables. I am almost certain that 316L was used in Micro Seiki's flagship, the mighty SX-8000 II (designed by the same guy).
Another advantage of 316L is extreme resistance to corrosion. My platter looks as nice as the day Mirko machined it for me, and my heirs will inherit a shiny platter years from now! The discoloration of the original bronze platter was annoying, requiring regular maintenance, especially here in South Florida (even in constant A/C).

Let me reiterate that my magnetic attraction test with a small neodymium magnet, while not scientific, reveals only a very tiny attraction to the platter, maybe half of what even the black granite base pulls (!), and that is very weak too. That same magnet snaps with great fury onto regular steel, with a force that is probably many hundred times more. In fact it is hard to remove it once stuck to regular steel. I will attach a table of the magnetic susceptibilities of materials. Compare austenitic stainless with regular iron. Thousands of times less magnetic, even after hard working.
Bottom line, I would not worry about it. With the CU-180 mat in place, it's completely a non-issue.
As to the bearing's ability to support the additional weight, it was a concern of mine too. Mirko, who knows these tables inside and out, and who has built clones, reassured me that the bearing was so overbuilt that it would not be a problem. I certainly have experienced no problems. Remember that Micro Seiki sold several heavy accessories intended to be use on their platters, such as the ST-20 stabilizer weight, the CU-500 heavy copper mat and the peripheral weight ring. Those could add up the total weight.
As with the bronze platter, one must be very careful when slowly lowering the platter down onto the bearing shaft. The ceramic ball and thrust plate inside are very hard, but also brittle.



______________
Brian
08-24-2017 Post does not mapped to Knowledge Tree
measet
Posts 15
Joined on 08-15-2017
Post #: 45
Post ID: 23370
Reply to: 23369
Micro SX-8000 feet
Thanks for detailed answer. I'll go for 316L. So I would not worry about magnet issue, especially because also I use CU-180 or Audio Technica AT-666EX mat (air suction type).

As my taste is closer to steel I have plan to make also the 316L version of pillars, to replicate the bigger SX-8000 feet is an option as well.
I just saw pictures and I modelled in 3d (attached) but I do not know the exact measurement of the bottom part.
Would be great if somebody can share the real dimensions of it.

Thanks a lot!
08-24-2017 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 46
Post ID: 23371
Reply to: 23370
Big feet
I am not sure that there would be an audible advantage to the larger feet, but they sure do look pretty nice!

I know that Mirko makes such feet, as well as feet for the motor unit. Unless you love machining, it might be easier to buy from him. I was worried that my new stainless platter from him would exhibit a little runout or wobbling due to the challenges of machining the conical spindle hole and making everything else precisely concentric and symmetrical. I needn't have worried; the platter spins perfectly. His work is impeccable and he knows these tables like no one else. By the way, I have zero business affiliation with him.

______________
Brian
08-24-2017 Post does not mapped to Knowledge Tree
measet
Posts 15
Joined on 08-15-2017
Post #: 47
Post ID: 23372
Reply to: 23371
Production of ss platter
Yes, also I'm worry about the fully precise production of platter. The sophisticated conical spindle hole gives reason for serious concern. Probably I will take out the spindle from bearing to obtain the right data for maximum fitting.
The raw material is a small fortune, there is no space for experimenting, for this work I have to find the master of masters.

Would be an option to agree with Mirko, but as I'm living in Budapest the hugh shipping cost and potentialy customs duties will increase the sum to the sky.
BTW how can I contact Mirko? Thanks a lot!
08-24-2017 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 48
Post ID: 23373
Reply to: 23372
Shipping
Shipping to Budapest should not be very expensive compared to the item itself. I know that Mirko Djordjevic has shipped overseas many times, so I expect he could tell you about customs costs. He has publicly shared his email in the past, so I will post it here, in minor disguise:

cary300b AT hotmail DOT com

Let us know what you do.



______________
Brian
09-14-2017 Post does not mapped to Knowledge Tree
measet
Posts 15
Joined on 08-15-2017
Post #: 49
Post ID: 23386
Reply to: 23373
Micro HS-80 flywheel
I found locally a professional mechanist, also I discovered a reliable supplier who can deliver me at relative low-cost the L316 raw material, so I'll start the steel platter project soon.

I just read some post in this thread regarding HS-80 flywheel and I would like to share my experience about it.
I got an original one from Japan in fantastic, mint condition but I'm totally disapointed regarding its performance.
Prectically is impossible to match it to my RX-5000 system.
Without the flywheel the speed of turntable is dead precise but the system breaks when I connect the HS-80.
I have to mention that the flywheel alone running smootly and stops after long time.
At start I help both platter by hands to speed them up but takes minutes to reach a certain speed level which finaly is unstable and uneven.
I followed many intructions regarding setup like both string (I have Micro one) must be equal lenght.
Also I tried the option what was advised here, that flywheel must be at the same distance as the motor and for adjustments has move the motor NOT the flywheel.
I played also with tension, the situation is better when treads are very-very tight but still far from ideal.

Now I have doubt that this gear was developed with intention to support the RX-5000.

Please let me know if you have any idea how can I force my HS-80 to perform well.

Thanks a lot!
09-14-2017 Post does not mapped to Knowledge Tree
Wellington


South Florida
Posts 38
Joined on 10-03-2011
Post #: 50
Post ID: 23387
Reply to: 23386
You are the second person to complain about the HS-80
An audiophile who has the user name "Kipdent" on other forums told me privately that he didn't think that he could hear any difference with the HS-80 using his RX-5000. He did not mention to me any problems getting it to function, however. While it does almost double the rotational inertia of the system (as I recall) it would introduce some additional machine noise. We might be at the point of diminishing returns with the high inertia of the RX-5000, especially if you add additional mass with a new platter.

______________
Brian
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