Looking at the Zoomed Image, there is appearing to be a non-flat texture to the surface of the thrust pad, this could be an inaccurate description as to what is produced.
I am not a specialist, far from it, but have been sharing over many years in many a discussion on using different sacrificial materials within a Bearing Housing, as well as being in discussions where the intention is to improve the mounting and rigidity of the bearing housing.
When taking a few moments on the idea of having a non-flat surface on a Thrust Pad, it seems it would be better suited in a assembly where the Steel Ball was a Free Part, and the Platter Spindle was rotating over the Ball.
On a TT with a Platter Spindle that has a Interference Fit Ball press fitted into the Spindle Base, the Ball is not a Free Part and will rotate with the Platter Spindle.
This type of assembly and a ball that rotates with the spindle being in contact with a non-flat surface in my mind would be a concern.
As a conjecture, it can suggest a condition is present at the interface that can generate a micro movement, and have potential to effect the Spindle during rotation.
This is a known concern when using a Thermoplastic as a Thrust Pad, and one of the reasons that some will consider using a Harder Material that has improved stability.
In my mind and the motivation to investigate, the idea of any modification within a assembly of Platter Spindles Bearing Housing,
is to improve on the conditions met when the Stylus is within the groove.
IMO, the intention of the modification, is to improve the eccentricity of a rotation, reduce the movement of the Spindle in any direction of travel, minimise the risk of a contact of parts coming into contact at a interface.
With these considerations in place and functioning in a improved manner over a previous assembly of materials, the result in a Layman's description is that an unwanted energy being generated which can transfer through the bearing assembly and reaching the stylus is now a decreased risk of occurring.
Any interface within the assembly that does not meet with the ideal conditions, is certainly one that can attribute to a different sonic being detected during a comparison of materials.
My experiences have assisted myself to form the view, in all areas of HiFi, with any Source in use, individuals like distortion, it is an accepted audible condition, even though the acceptance levels vary by a vast range across different listeners.
Knowing it is present is an attribute to the ability to listen, it is usually only when the presence of a distortion is no longer detected, that the levels of a distortion accepted by an individual can determined.
When it comes to a Source that has a requirement that is necessary to have mechanics included in the overall function of the operation,
(usually analogue)
The additional measures that are seen to be adopted to improve on the interfaces, where the benefits of these practices are usually instantaneously detected as less noticeable noise/distortion, is usually reported on as being an attractor and the previous methods are not considered as having any need to be returned to.
This positive result, can be found from the thought process being applied to a Cartridge, Tonearm or Turntable.
I am not a specialist, far from it, but have been sharing over many years in many a discussion on using different sacrificial materials within a Bearing Housing, as well as being in discussions where the intention is to improve the mounting and rigidity of the bearing housing.
When taking a few moments on the idea of having a non-flat surface on a Thrust Pad, it seems it would be better suited in a assembly where the Steel Ball was a Free Part, and the Platter Spindle was rotating over the Ball.
On a TT with a Platter Spindle that has a Interference Fit Ball press fitted into the Spindle Base, the Ball is not a Free Part and will rotate with the Platter Spindle.
This type of assembly and a ball that rotates with the spindle being in contact with a non-flat surface in my mind would be a concern.
As a conjecture, it can suggest a condition is present at the interface that can generate a micro movement, and have potential to effect the Spindle during rotation.
This is a known concern when using a Thermoplastic as a Thrust Pad, and one of the reasons that some will consider using a Harder Material that has improved stability.
In my mind and the motivation to investigate, the idea of any modification within a assembly of Platter Spindles Bearing Housing,
is to improve on the conditions met when the Stylus is within the groove.
IMO, the intention of the modification, is to improve the eccentricity of a rotation, reduce the movement of the Spindle in any direction of travel, minimise the risk of a contact of parts coming into contact at a interface.
With these considerations in place and functioning in a improved manner over a previous assembly of materials, the result in a Layman's description is that an unwanted energy being generated which can transfer through the bearing assembly and reaching the stylus is now a decreased risk of occurring.
Any interface within the assembly that does not meet with the ideal conditions, is certainly one that can attribute to a different sonic being detected during a comparison of materials.
My experiences have assisted myself to form the view, in all areas of HiFi, with any Source in use, individuals like distortion, it is an accepted audible condition, even though the acceptance levels vary by a vast range across different listeners.
Knowing it is present is an attribute to the ability to listen, it is usually only when the presence of a distortion is no longer detected, that the levels of a distortion accepted by an individual can determined.
When it comes to a Source that has a requirement that is necessary to have mechanics included in the overall function of the operation,
(usually analogue)
The additional measures that are seen to be adopted to improve on the interfaces, where the benefits of these practices are usually instantaneously detected as less noticeable noise/distortion, is usually reported on as being an attractor and the previous methods are not considered as having any need to be returned to.
This positive result, can be found from the thought process being applied to a Cartridge, Tonearm or Turntable.
the finish is as it left the lathe,i didnt want any abrasive particles from sand paper embeded in the thrust pads surface,besides the only area that matters is where the ball makes contact the rest isn't touching anything,the ball area will soon polish itself up nicely.
Nice implementation. I was wondering if having a convex thrust pad would have any advantage of durability ? As by passage of time it will flatten out and we have the same surface as new. A small magnet to levitate the platter so as the spindle just touches the surface of thrust pad would be beneficial too as pressure of platter weight will be less.
There are various forms to a Thrust Pad, some even have a design where a raised nipple for the Ball to seat and rotate on, this could be described as Convex.
There are also designs that are the opposite with a indentation to locate the ball, which could be described as Concave.
In general if a design is thought out a Ball that is free is located in a way that restricts anu unwanted sideways movement, and other designs have the Ball as a Interference Fit and housed in the Spindle.
There does seem to be a lot more options for a Thrust Pad Material if a Flat Surface is the chosen finish.
I am from a discipline where I load the OEM Platter with additional weight, I have a Gun Metal Mat used occasionally on some owned TT's and also own a Gun Metal Platter for another TT.
The GM Platter is to be modified to enable the use of it on other TT's.
A Periphery Ring is also on the radar, so the idea of using Magnet Levitation is for me difficult to consider.
Where the levitation does sound as it can offer an attraction is when in use, it might be able to offer an additional value and allow for a Hydrodynamic Lubrication between the Ball and Spindle / Ball and Thrust Pad, through restricting the parts receive the bearing of the full weight and reduce the impact on displacement of lubricant.
There are also designs that are the opposite with a indentation to locate the ball, which could be described as Concave.
In general if a design is thought out a Ball that is free is located in a way that restricts anu unwanted sideways movement, and other designs have the Ball as a Interference Fit and housed in the Spindle.
There does seem to be a lot more options for a Thrust Pad Material if a Flat Surface is the chosen finish.
I am from a discipline where I load the OEM Platter with additional weight, I have a Gun Metal Mat used occasionally on some owned TT's and also own a Gun Metal Platter for another TT.
The GM Platter is to be modified to enable the use of it on other TT's.
A Periphery Ring is also on the radar, so the idea of using Magnet Levitation is for me difficult to consider.
Where the levitation does sound as it can offer an attraction is when in use, it might be able to offer an additional value and allow for a Hydrodynamic Lubrication between the Ball and Spindle / Ball and Thrust Pad, through restricting the parts receive the bearing of the full weight and reduce the impact on displacement of lubricant.
Those photos are seriously impressive. Absolutely take your point about abrasive paper possibly embedding abrasive dust. It looks as though the machining wasn't quite ideal. I've a nasty suspicion that lignum vitae will turn out to be one of those awkward sticky materials that needs a very fast feed rate to prevent build-up on the tip of the tool. I'm told (never tried it) that Pritt Stick can be good for copper (another sticky material). Your Hobbymat photograph didn't explicitly show it, but it looked like some sort of a tip tool for non-ferrous metal, with quite a substantial rake? I shall do some experimenting to see if a better finish is possible, but as you point out, it's probably immaterial and will polish up quickly.
Naturally, we know the rotational speed of the bearing in use, but what was the mass of the platter and mat?
Very Soon, I am being reassured from a recent conversation, I am in absolutely no rush, as I am not with a full System at present, most is ready to go into storage for possibly a year as the minimum.
Temporary accommodation is not going to work with Large Overbearing Valve Equipment.
I am seriously considering a not too expensive Computer Source System with all SS miniature devices downstream to get through the period. Something new to work with and a modern replay method will keep me inquisitive and learning a few new tricks.
Who knows I might struggle to return to an Analogue Source 😱
The Platter Mod' is the sticking point, it is to have a modification and a sleeve produced and interference fitted to be a much improved fit to the Spindle.
The New Seals following your testing are available for the purpose of producing a functioning lubricant sump within the Bowl.
The additional bracing to be used on the Bowl and New Bush Sleeves are all in hand as far as I am aware.
It is easier with the present situation to not press for anything as the TT is probably better off with the Engineer, and a few things are developing with another TT that I am keen to see materialise.
I have been involved as well with the The SP10 MkII, there is a lot to happen from two different resources.
I have been able to generate an interest from the individuals who are adept in the skills to produce the work, it is now looking like both individuals have got their own ideas that are to materialise this year as a prototype design.
A New Bearing Design is in the making from one resource and the other resource is working on a complete redesign for the TT, this design is to have a purpose produced platter.
If all goes well there should be an option to amalgamate both of the works.
Being asked to share in the experiencing the works as they develop will keep me enthusiastic during my absence from having a functioning Vinyl LP Source.
It would be great to have the owned TTS 8000 in a P'holz/Permali Plinth and compare it to either of the upcoming modified SP10 MkII's or an amalgamated version of both the works.
Temporary accommodation is not going to work with Large Overbearing Valve Equipment.
I am seriously considering a not too expensive Computer Source System with all SS miniature devices downstream to get through the period. Something new to work with and a modern replay method will keep me inquisitive and learning a few new tricks.
Who knows I might struggle to return to an Analogue Source 😱
The Platter Mod' is the sticking point, it is to have a modification and a sleeve produced and interference fitted to be a much improved fit to the Spindle.
The New Seals following your testing are available for the purpose of producing a functioning lubricant sump within the Bowl.
The additional bracing to be used on the Bowl and New Bush Sleeves are all in hand as far as I am aware.
It is easier with the present situation to not press for anything as the TT is probably better off with the Engineer, and a few things are developing with another TT that I am keen to see materialise.
I have been involved as well with the The SP10 MkII, there is a lot to happen from two different resources.
I have been able to generate an interest from the individuals who are adept in the skills to produce the work, it is now looking like both individuals have got their own ideas that are to materialise this year as a prototype design.
A New Bearing Design is in the making from one resource and the other resource is working on a complete redesign for the TT, this design is to have a purpose produced platter.
If all goes well there should be an option to amalgamate both of the works.
Being asked to share in the experiencing the works as they develop will keep me enthusiastic during my absence from having a functioning Vinyl LP Source.
It would be great to have the owned TTS 8000 in a P'holz/Permali Plinth and compare it to either of the upcoming modified SP10 MkII's or an amalgamated version of both the works.
1.35
LV machines lovely,i tried all the speeds on my lathe,if i remember rightly 500 rpm was good,reaming a lot slower.
i would guess the platter and ceramic mat i use weigh approx 5.5 lbs.
cheers,please dont assume the bearings have the same finish,they dont,i just gave the thrust pad a quick pass over on the lathe.,the photos are taken with a 12x loupe over the iphone lense,they make the ridges look a lot worse than they are,in reality you can't see or feel them.
LV machines lovely,i tried all the speeds on my lathe,if i remember rightly 500 rpm was good,reaming a lot slower.
i would guess the platter and ceramic mat i use weigh approx 5.5 lbs.
exciting times then!
i have tried to 'get on' with my sp10 but to be honest since the torlon and then LV mods i much prefer the more meaty sound of the sony,thats in my system of course.
I saw you managed a very nice finish on bearing sleeves. 500rpm noted. Yes, reaming needs to be much slower. I fitted the slow speed attachment to my Hobbymat, so it can run quite slowly. 5.5 lbs is a little lighter than my granite chopping board, but I don't see that being a problem.
You might want to consider bracing the bottom of the platter bearing to the plinth. I did that on my Garrard 301 and it converted a somewhat soggy bass into very clean bass.
You might want to consider bracing the bottom of the platter bearing to the plinth. I did that on my Garrard 301 and it converted a somewhat soggy bass into very clean bass.
I found Lignum to machine very nicely. HSS tool honed razor sharp at any moderate speed. Naturally I have a page on lathe tools- http://www.conradhoffman.com/advancedsharp.htm
If your making a round part on the lathe you'll have a small defect of some sort in the center, as the tool is never perfectly on center and the surface speed drops to zero at the center. Don't be afraid to put the finished diameter stock in the 4-jaw and surface it off center. Or, fly cut it on the mill. Or use your scraper, though it's a bit awkward on a small disk.
It's critical to never sand or polish, only cut with a tool or scrape with a scraper, lest you get grit in the surface. I saw a scratch on the ball when I tested maple and wondered if some woods have natural mineral content.
I'm curious how the Torlon does. I have some available but didn't test it when I was testing other materials. May have to add it to the list, but I found even the best and most expensive engineering plastics weren't as good as purpose designed bearing plastics from IGUS, or various woods.
If your making a round part on the lathe you'll have a small defect of some sort in the center, as the tool is never perfectly on center and the surface speed drops to zero at the center. Don't be afraid to put the finished diameter stock in the 4-jaw and surface it off center. Or, fly cut it on the mill. Or use your scraper, though it's a bit awkward on a small disk.
It's critical to never sand or polish, only cut with a tool or scrape with a scraper, lest you get grit in the surface. I saw a scratch on the ball when I tested maple and wondered if some woods have natural mineral content.
I'm curious how the Torlon does. I have some available but didn't test it when I was testing other materials. May have to add it to the list, but I found even the best and most expensive engineering plastics weren't as good as purpose designed bearing plastics from IGUS, or various woods.
It's worth fitting the slow speed attachment, although it is alarming to fit (drilling holes in your lathe). Get it right and the pulley cover still fits. But there really isn't a lot of room. I have seen people who made a muck of it hacking bits out of the cover, making the whole thing look a complete mess.
Something you might want to consider is that the weight of the motor hanging off to one side tends to twist the lathe bed, causing you to machine cones rather than cylinders. It's not much, but I discovered it when I bought a micrometer that genuinely could measure microns. The cure is to fit an adjustable foot between the overhanging part of the head and your bench. Adjust foot (on screw thread) to eliminate twist, as evidenced by cylinders being machined, rather than gentle cones.
Something you might want to consider is that the weight of the motor hanging off to one side tends to twist the lathe bed, causing you to machine cones rather than cylinders. It's not much, but I discovered it when I bought a micrometer that genuinely could measure microns. The cure is to fit an adjustable foot between the overhanging part of the head and your bench. Adjust foot (on screw thread) to eliminate twist, as evidenced by cylinders being machined, rather than gentle cones.
I had never thought of deliberately machining off centre. Obvious, once stated.
What about polishing using paper? I found a diary I had was excellent when I needed to produce an optically transparent surface on a horribly low melting point transparent plastic.
On the subject of using steel balls as a thrust bearing, I seem to remember that the Yam SR 125 had a spindle with a hole through it, filled with steel balls ( the hole was the same diameter as the balls, so they were all in a line ) as a thrust bearing for the clutch, presumably as one wore a flat on, the increased friction would cause it to rotate and wear the next contact point, until all the balls had flats on. I'm not sure that many bearing surfaces in series would be stable enough for a vinyl thrust bearing though.
On the subject of chips sticking to lathe tools, I use a CBN ultra fine hone on carbide tools, it greatly inproves the finish and presumably helps the chips slide off.
With an abrasive grit, the principal seems to be it will always be imbedded into the softer material ( by the harder one ), this is why wooden laps are used on metal cylinders.
On the subject of chips sticking to lathe tools, I use a CBN ultra fine hone on carbide tools, it greatly inproves the finish and presumably helps the chips slide off.
With an abrasive grit, the principal seems to be it will always be imbedded into the softer material ( by the harder one ), this is why wooden laps are used on metal cylinders.
On really small carbide boring bars, I used a too called an "India Stone". Guessing it's similar to a CBN hone.
jeff
India Stone is Aluminum Oxide, trade mark of Norton.
Much softer than Silicon Carbide, which is correct for carbide tips used in metal working machines.
CBN is Cubic Boron Nitride, hardness is only next to diamond, and is used as a much cheaper substitute for diamond tools.
Expensive in comparison to Silicon Carbide (grey / black) abrasives.
Much softer than Silicon Carbide, which is correct for carbide tips used in metal working machines.
CBN is Cubic Boron Nitride, hardness is only next to diamond, and is used as a much cheaper substitute for diamond tools.
Expensive in comparison to Silicon Carbide (grey / black) abrasives.
Indeed 9.2<< 9.3 on Mohs scale...
Although discussed already it seems that this wood is a slightly better replacement at least for The Well Tempered turntable's teflon upwards gimbal as the wood seems to be harder than teflon.By the way...i just bought from the flea market a considerable amount(about 3kg for 3 bucks) of 7mm...1.5 cm thick teflon sheets.I bet they are more consistent and predictable in specs than lignum vitae and certainly much cheaper to source.The original plastics that Sony had looked more like usual nylon for fishing nets.Teflon is compresible so it can't be used for the horizontal bearing unless the whole system allows for a mm vertical play but threading it is a children's game.You can do it bare handed.You could have used the original dead iron bushing container to thread it.
Although discussed already it seems that this wood is a slightly better replacement at least for The Well Tempered turntable's teflon upwards gimbal as the wood seems to be harder than teflon.By the way...i just bought from the flea market a considerable amount(about 3kg for 3 bucks) of 7mm...1.5 cm thick teflon sheets.I bet they are more consistent and predictable in specs than lignum vitae and certainly much cheaper to source.The original plastics that Sony had looked more like usual nylon for fishing nets.Teflon is compresible so it can't be used for the horizontal bearing unless the whole system allows for a mm vertical play but threading it is a children's game.You can do it bare handed.You could have used the original dead iron bushing container to thread it.
