I have some experience for this work, but a single unit is more trouble than the effort.
See posts # 6 & 13 in this thread.
My suggestions are practical, and do not involve a complex calculation that ends up specifying a particular grade of lubricant to be made for one job.
I did all this in grad school, designing gears and bearings, among other machine elements.
Still have my design handbooks: Lingaiah and Iyengar, both volumes.
Finished grad school in 1989.
Is it enough to qualify as a person with the knowledge and experience to recommend a bicycle quality low speed bearing?
See posts # 6 & 13 in this thread.
My suggestions are practical, and do not involve a complex calculation that ends up specifying a particular grade of lubricant to be made for one job.
I did all this in grad school, designing gears and bearings, among other machine elements.
Still have my design handbooks: Lingaiah and Iyengar, both volumes.
Finished grad school in 1989.
Is it enough to qualify as a person with the knowledge and experience to recommend a bicycle quality low speed bearing?
Again, I have no concerns to be raised with an off the shelve Lubricant.
With the modern approach to using Thermoplastic Parts in bearing housings and as the preferred material to exchange perished parts found in Vintage designs for bearing housings.
The Thermoplastic Materials with the latest composition are usually improved on as a material that is suitable for low temperature environments.
When the exchange part is produced, as a part to work in a bearing that generates low revolutions for the axial, the range of viscosities available in
Silicone Oils, will offer a ideal viscosity for use in the bearing housing when working with Thermoplastics and Low Temperatures, the Silicone Oil is a lubricant type worth considering.
A Producer of performance cycles who is based in Germany has recently learnt off and commenced with adopting the approach of using modern design materials for their owned vintage TT's.
The Plinth design is complete, and I have had parts produced in Torlon for them and others with the same models, to enable them to swap out the original Sintered Bronze Housing Liners.
There is very useful information available as well, on how to produce a Base to the Bearing Housing that retains lubricant.
There is also a redesign for the Thrust Pad Interface and there are produced parts for the design for the thrust pad, along with the exchange of the base of the Spindles Steel interference fit ball, to a low co-efficient of friction alternative.
On one of the Vintage TT's an additional design is also in place to be used as an anchor point and reduce flexion that impacts on the Spindle Rotation.
The reports returned by the individuals that have completed the entirety of the modifications and subsequently carried out comparisons to a unmodified TT of the same model, in the same plinth > tonearm > cartridge are quite encouraging, and the small costs incurred to produce the mod's seem to have yielded very large improvement and worthwhile to be made known.
With the modern approach to using Thermoplastic Parts in bearing housings and as the preferred material to exchange perished parts found in Vintage designs for bearing housings.
The Thermoplastic Materials with the latest composition are usually improved on as a material that is suitable for low temperature environments.
When the exchange part is produced, as a part to work in a bearing that generates low revolutions for the axial, the range of viscosities available in
Silicone Oils, will offer a ideal viscosity for use in the bearing housing when working with Thermoplastics and Low Temperatures, the Silicone Oil is a lubricant type worth considering.
A Producer of performance cycles who is based in Germany has recently learnt off and commenced with adopting the approach of using modern design materials for their owned vintage TT's.
The Plinth design is complete, and I have had parts produced in Torlon for them and others with the same models, to enable them to swap out the original Sintered Bronze Housing Liners.
There is very useful information available as well, on how to produce a Base to the Bearing Housing that retains lubricant.
There is also a redesign for the Thrust Pad Interface and there are produced parts for the design for the thrust pad, along with the exchange of the base of the Spindles Steel interference fit ball, to a low co-efficient of friction alternative.
On one of the Vintage TT's an additional design is also in place to be used as an anchor point and reduce flexion that impacts on the Spindle Rotation.
The reports returned by the individuals that have completed the entirety of the modifications and subsequently carried out comparisons to a unmodified TT of the same model, in the same plinth > tonearm > cartridge are quite encouraging, and the small costs incurred to produce the mod's seem to have yielded very large improvement and worthwhile to be made known.
No Secrets, the information is freely available.
To get the idea of how a modern thought process has been considered for a state of the art TT design look no further than the Kuzma Stabi R.
A Milled Chassis from Solid Aluminium Block, selected as the method to minimise flexion at the bearing housing mounting point, a Gem Stone Ball within the housing, used in place of a steel ball and low noise materials used for the other interfaces, which I am certain will be Thermoplastics of a composition that works best in a low heat environment.
There is a Company producing 401 Chassis from milled Aluminium Block for this same reason, and I am sure if I looked into their Bearing Housing design there will be a familiar list of materials chosen.
To see a similar concept in use for these designs where older bearing designs belonging to Vintage Models are modified to use modern materials, the Lenco Heaven forum is a great place to discover work undertaken, and as said a business that is offering complete exchange bearing housings for a variety of Vintage TT's can be found on here along with user reports on the assessment of the exchange.
My PTP Solid Nine also has the design incorporated to eliminate flexion of the chassis, as well as having attached to the chassis, the new bearing housing option that incorporates the modern materials referred to at the interfaces.
There are discussions on a wide variety of blogs and forums sharing information on this subject and showing completed work.
To get the idea of how a modern thought process has been considered for a state of the art TT design look no further than the Kuzma Stabi R.
A Milled Chassis from Solid Aluminium Block, selected as the method to minimise flexion at the bearing housing mounting point, a Gem Stone Ball within the housing, used in place of a steel ball and low noise materials used for the other interfaces, which I am certain will be Thermoplastics of a composition that works best in a low heat environment.
There is a Company producing 401 Chassis from milled Aluminium Block for this same reason, and I am sure if I looked into their Bearing Housing design there will be a familiar list of materials chosen.
To see a similar concept in use for these designs where older bearing designs belonging to Vintage Models are modified to use modern materials, the Lenco Heaven forum is a great place to discover work undertaken, and as said a business that is offering complete exchange bearing housings for a variety of Vintage TT's can be found on here along with user reports on the assessment of the exchange.
My PTP Solid Nine also has the design incorporated to eliminate flexion of the chassis, as well as having attached to the chassis, the new bearing housing option that incorporates the modern materials referred to at the interfaces.
There are discussions on a wide variety of blogs and forums sharing information on this subject and showing completed work.
We say here buy a buffalo if you have grass.
You want somebody to buy or build a new TT just because his bearing needs repair?
Your thinking is not practical in my opinion...
You want somebody to buy or build a new TT just because his bearing needs repair?
Your thinking is not practical in my opinion...
When an individual develops the interest in what the bearing assembly is looking like on a TT.
The simplicity of the procedures required to assess the condition and exchange a few sacrificial parts within a Bearing Housing whilst giving it an attention, such as a service is a very easy accomplishment.
The OP has already undertaken the first works to carry out a service and has supplied Photo Evidence of a discovery made, by Post 3 the suggestion to exchange the sacrificial part in the photograph is already made, which leads onto further discussion about options by different contributors.
At no time within this thread has a suggestion been made that a new TT is required, there has only been suggestions on the different materials that can be considered, to be used as sacrificial parts and additionally the referencing methods that can be considered to improve the rigidity of the bearing housing mounting when attached to the original chassis.
If a individual is incorporating exchanging parts as part of the treatment to the assembly of the bearing, it was also made known to produce an optimised environment, the more difficult part to achieve of the overall treatment is a Hydrodynamic condition for the lubricant at the critical interfaces.
All suggested methods from all contributors to the thread, are methods that have been put to use before by TT' enthusiasts from a broad range of forums and blogs, these individuals are taking their time to share their work undertaken, onlookers with a bit of mechanical savvy like seeing the procedures used and some adopt the methods.
When looking at commercially available products, the methods used and described in the sales pitch, for a use of materials and a treatment of the assembly within the bearing, are ones that have been successfully used by DIY enthusiasts, and the methods adopted by the commercial side,
are most likely plagiarised and are now seen as commercial offering.
For the inexperienced and maybe developing a curiosity, or for the types who feel confident to have a indulgence and have a look inside a Bearing Housing.
Nearly all sacrificial parts are able to be purchased as 'off the shelf' items, some of the parts on offer are seen as very low co-efficient of friction and are seen to attractive, such parts can be quite fragile and not robust, how the TT is used with these parts in will need to be a consideration, extra thought would be needed if transportation of the TT was occurring .
The acquiring a part becomes a little more complex when a Thermoplastic Sleeve is selected to be used from a not too commonly seen Thermoplastic material.
There are Companies that produce Thermoplastic parts to be used as exchange parts for a selection of TT's.
The simplicity of the procedures required to assess the condition and exchange a few sacrificial parts within a Bearing Housing whilst giving it an attention, such as a service is a very easy accomplishment.
The OP has already undertaken the first works to carry out a service and has supplied Photo Evidence of a discovery made, by Post 3 the suggestion to exchange the sacrificial part in the photograph is already made, which leads onto further discussion about options by different contributors.
At no time within this thread has a suggestion been made that a new TT is required, there has only been suggestions on the different materials that can be considered, to be used as sacrificial parts and additionally the referencing methods that can be considered to improve the rigidity of the bearing housing mounting when attached to the original chassis.
If a individual is incorporating exchanging parts as part of the treatment to the assembly of the bearing, it was also made known to produce an optimised environment, the more difficult part to achieve of the overall treatment is a Hydrodynamic condition for the lubricant at the critical interfaces.
All suggested methods from all contributors to the thread, are methods that have been put to use before by TT' enthusiasts from a broad range of forums and blogs, these individuals are taking their time to share their work undertaken, onlookers with a bit of mechanical savvy like seeing the procedures used and some adopt the methods.
When looking at commercially available products, the methods used and described in the sales pitch, for a use of materials and a treatment of the assembly within the bearing, are ones that have been successfully used by DIY enthusiasts, and the methods adopted by the commercial side,
are most likely plagiarised and are now seen as commercial offering.
For the inexperienced and maybe developing a curiosity, or for the types who feel confident to have a indulgence and have a look inside a Bearing Housing.
Nearly all sacrificial parts are able to be purchased as 'off the shelf' items, some of the parts on offer are seen as very low co-efficient of friction and are seen to attractive, such parts can be quite fragile and not robust, how the TT is used with these parts in will need to be a consideration, extra thought would be needed if transportation of the TT was occurring .
The acquiring a part becomes a little more complex when a Thermoplastic Sleeve is selected to be used from a not too commonly seen Thermoplastic material.
There are Companies that produce Thermoplastic parts to be used as exchange parts for a selection of TT's.
I was chatting my my local engineer buddy and he showed me this grease that was a $60 tube, I'll attach a pic, it's called "krytox." Apparently there are many different flavors, and many price points up to a grand, I assume for the same tube. That's cool!
And galling. That's something that happens to ball bearings over time. There was a specific steel designed to resist galling in a "low lube" environment like a turn table, its called Nitronic (wikipedia), and apparently you can get ball bearings made of the stuff too.
From Mcmaster
Chemours Krytox™ XHT-BDX—Boron Nitride Thickener is the spendy stuff they've got at $144 for 2oz and $1400 for a tube of it. Good times.
https://www.mcmaster.com/krytox/
And galling. That's something that happens to ball bearings over time. There was a specific steel designed to resist galling in a "low lube" environment like a turn table, its called Nitronic (wikipedia), and apparently you can get ball bearings made of the stuff too.
From Mcmaster
Chemours Krytox™ XHT-BDX—Boron Nitride Thickener is the spendy stuff they've got at $144 for 2oz and $1400 for a tube of it. Good times.
https://www.mcmaster.com/krytox/
UHMW is a wonderful material in many ways, but very difficult to machine accurately. You've been warned.
All these posts for one turn table...or two.
Nitriding quality steels have been around for years, and I doubt you would get a few dozen stainless steel balls to service a TT.
They would be harder than regular, so risk of galling the races (or cups, whatever).
So no point, the worn part becomes the difficult to service one, easier to change balls.
Friend used to have a factory for plastic processing machines, and he put gears in the shredders, did not have machining issues with UHMW, though the people who did it were experienced gear makers...I was the one who identified the material, it was from a Chinese machine, and told him where to get it...it was exotic then for most in India.
There are different grades, and like I said above, 'if you can", otherwise in a TT, the alternates of Teflon, and Delrin are quite adequate.
Nitriding quality steels have been around for years, and I doubt you would get a few dozen stainless steel balls to service a TT.
They would be harder than regular, so risk of galling the races (or cups, whatever).
So no point, the worn part becomes the difficult to service one, easier to change balls.
Friend used to have a factory for plastic processing machines, and he put gears in the shredders, did not have machining issues with UHMW, though the people who did it were experienced gear makers...I was the one who identified the material, it was from a Chinese machine, and told him where to get it...it was exotic then for most in India.
There are different grades, and like I said above, 'if you can", otherwise in a TT, the alternates of Teflon, and Delrin are quite adequate.
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That would be kind of expensive, and would lead to a discussion on machining perfect diamond spheres!
Cubic Boron Nitride is an alternate, but like I said, the worn part then becomes the tough one to service.
Cubic Boron Nitride is an alternate, but like I said, the worn part then becomes the tough one to service.
Has anyone actually proven that using a harder ball bearing than the standard off the shelf precision balls made from 52100 series bearing steel actually make a performance difference? The hardness of these balls is anywhere from Rockwell 60 to 67 on the C scale!
Sure, carbide balls are much harder but if your running it against a softer material does that really make a difference?
I have been working on a Russco Studio Pro restoration along with a few other folks I know. The main spindle is 0.7500 inch diameter with two styles of thrust bearings. One is a flat ground bottom pad on the steel spindle and the other has a pressed in 3/8" diameter steel bearing ball.
On both style of bearings the lower bearing "pad" is a 1/2" set screw with a smaller bearing pressed into the end.
So in one instance there is a ball on ball interface and in the other instance there is a flat hardened steel pad on a ball interface. Neither in my opinion is a good solution.
I purchased some high quality brass setscrews and a piece of Delrin rod from McMaster Carr to replace the setscrew with hardened bearing ball. I machined a 0.340 diameter x 0.125 deep pocket in the end of the brass set screw and made a Delrin pad 0.125 thick that presses in the pocket.
I shipped one piece to my friend in Texas who was building a Russco as he had a flat bottomed spindle and was further along in his build than I. This fellow is a huge idler drive fan and has restored many vintage tables along with building furniture grade high mass plinths.
As soon as it was installed he wrote an email to me as he was very excited, it achieved a dramatic reduction in noise as I had suspected it would. He also had a custom Delrin idler wheel made with rubber tire (square rubber o-ring) and supplied me with one as well. This further reduced any noise from this idler drive table to the point that it is used along side his restored Thorens TD124.
Both are reference quality, each table sports two tonearms so he can use different cartridges. His Denon DP-80 sits on the sidelines. Yes, the Denon DP-80 is a bit quieter as measured by him using a transducer and scope but in the real world makes no difference, he just prefers the delivery of music on a high quality idler drive.
My friends method of checking for bearing noise, in this case clearly an audible reduction, is to set a hard block next to the platter and rest the tonearm on the block. The cartridge output is that measured on his scope and recorded as the platter is run at speed. Of course this picks up any and all vibrations from both the substantial AC motor and the idler wheel as well. One can also keep the table in neutral without the motor running and spin the platter by hand. The problem with that is the time base on the scope is of no use in identifying what is causing any noise.
So far, neither of us has done anything with the sintered bronze Oilite bearings that are used in the main bearings. I have measured the clearance on mine and found it to be excessive at 0.0013 even after installing new Oilite sleeves. I would like to see this clearance brought down to 0.0007 to 0.0008. I typically use a high quality AW-32 turbine or hydraulic oil for it's great inherent properties.
By the way, that excessive clearance is by design as these turntables were a broadcast radio station staple, used everywhere, run 24/7 and saw little maintenance in many cases. The last thing a station manager wanted was a turntable that had a seized spindle. So these tables, massively built were sloppy were needed and precision as needed as well.
I suspect there are further gains to be made by machining a new bearing housing and using high quality bearing bronze sleeves, not Oilite, precision sized using a hone. This will allow me to achieve the closer running fit that I desire. I have always used a rule of thumb of 0.001 inch clearance per inch of shaft diameter for a plain bearing running in non hydrodynamic conditions, a turntable platter is running painfully slow so fits those conditions.
Back to my question, has anyone actually measured the noise differences in say a precision steel ball, ceramic or a tungsten carbide ball? If so, against what kind of bearing pad? Delrin, Torin, steel sapphire?
BillWojo
Sure, carbide balls are much harder but if your running it against a softer material does that really make a difference?
I have been working on a Russco Studio Pro restoration along with a few other folks I know. The main spindle is 0.7500 inch diameter with two styles of thrust bearings. One is a flat ground bottom pad on the steel spindle and the other has a pressed in 3/8" diameter steel bearing ball.
On both style of bearings the lower bearing "pad" is a 1/2" set screw with a smaller bearing pressed into the end.
So in one instance there is a ball on ball interface and in the other instance there is a flat hardened steel pad on a ball interface. Neither in my opinion is a good solution.
I purchased some high quality brass setscrews and a piece of Delrin rod from McMaster Carr to replace the setscrew with hardened bearing ball. I machined a 0.340 diameter x 0.125 deep pocket in the end of the brass set screw and made a Delrin pad 0.125 thick that presses in the pocket.
I shipped one piece to my friend in Texas who was building a Russco as he had a flat bottomed spindle and was further along in his build than I. This fellow is a huge idler drive fan and has restored many vintage tables along with building furniture grade high mass plinths.
As soon as it was installed he wrote an email to me as he was very excited, it achieved a dramatic reduction in noise as I had suspected it would. He also had a custom Delrin idler wheel made with rubber tire (square rubber o-ring) and supplied me with one as well. This further reduced any noise from this idler drive table to the point that it is used along side his restored Thorens TD124.
Both are reference quality, each table sports two tonearms so he can use different cartridges. His Denon DP-80 sits on the sidelines. Yes, the Denon DP-80 is a bit quieter as measured by him using a transducer and scope but in the real world makes no difference, he just prefers the delivery of music on a high quality idler drive.
My friends method of checking for bearing noise, in this case clearly an audible reduction, is to set a hard block next to the platter and rest the tonearm on the block. The cartridge output is that measured on his scope and recorded as the platter is run at speed. Of course this picks up any and all vibrations from both the substantial AC motor and the idler wheel as well. One can also keep the table in neutral without the motor running and spin the platter by hand. The problem with that is the time base on the scope is of no use in identifying what is causing any noise.
So far, neither of us has done anything with the sintered bronze Oilite bearings that are used in the main bearings. I have measured the clearance on mine and found it to be excessive at 0.0013 even after installing new Oilite sleeves. I would like to see this clearance brought down to 0.0007 to 0.0008. I typically use a high quality AW-32 turbine or hydraulic oil for it's great inherent properties.
By the way, that excessive clearance is by design as these turntables were a broadcast radio station staple, used everywhere, run 24/7 and saw little maintenance in many cases. The last thing a station manager wanted was a turntable that had a seized spindle. So these tables, massively built were sloppy were needed and precision as needed as well.
I suspect there are further gains to be made by machining a new bearing housing and using high quality bearing bronze sleeves, not Oilite, precision sized using a hone. This will allow me to achieve the closer running fit that I desire. I have always used a rule of thumb of 0.001 inch clearance per inch of shaft diameter for a plain bearing running in non hydrodynamic conditions, a turntable platter is running painfully slow so fits those conditions.
Back to my question, has anyone actually measured the noise differences in say a precision steel ball, ceramic or a tungsten carbide ball? If so, against what kind of bearing pad? Delrin, Torin, steel sapphire?
BillWojo
You get interred bearing sleeves / bushes, we have a company called Mahindra Sintered Products, and another in Goa.
Those may save you some work, buying ready sintered sleeves for your tables.
They are generally 2 triangle finish ground inside and outside.
Step sizes to compensate wear are also sometimes available.
Those may save you some work, buying ready sintered sleeves for your tables.
They are generally 2 triangle finish ground inside and outside.
Step sizes to compensate wear are also sometimes available.
Problem with using pre-made sleeves is they crush a bit when pressed in. So getting the desired bore size within a "tenth" or so is very problematical. I'd rather use good bearing bronze and leave about 0.005 inch in the bore for final sizing with a hone. As long as a sufficient amount of lube is in the bearing well to flood the top bearing, your good.
I can do all the machining except the final honing to size, not spending 2 to 3 hundred for a long mandrel to do one project. I'll send that out.
BillWojo
I can do all the machining except the final honing to size, not spending 2 to 3 hundred for a long mandrel to do one project. I'll send that out.
BillWojo
Bi metal bearings, the kind used in engine cranks, may work too.
Sintered bushes are powder metal sponge, designed for push fit, not press fit.
So should not crush.
But you would know better from experience.
In #94 above, 'sintered' got auto corrected to 'interred'!
Please take this as a correction.
Sintered bushes are powder metal sponge, designed for push fit, not press fit.
So should not crush.
But you would know better from experience.
In #94 above, 'sintered' got auto corrected to 'interred'!
Please take this as a correction.
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Mahindra Sintered is now part of GKN powder metallurgy:
https://www.gknpm.com/en/products/sintered-sliding-bearings/
Goa Sintered Products:
http://goasintered.com/product/home-appliances/
https://www.gknpm.com/en/products/sintered-sliding-bearings/
Goa Sintered Products:
http://goasintered.com/product/home-appliances/
Milling from the block is expensive and somewhat low grade way to produce a part. It is the way to go wth one offs or low quantity production. If you want all out quality the way to go is to cast the piece slightly oversize and then machine to tolerance.
Actually machining parts from a solid block usually results in a much stronger part than a casting. For the ultimate in strength a forging to net shape with machining to final size is best.
This is based on visiting thousands of shops in my career, many that are working on military contracts.
In the case of the 401 plinth, it's a darn bit cheaper to produce a very limited number of them by milling from a solid plate of aluminum than to design and build an injection mold. Even having it sand casted will require an expensive mold and the upfront cost would be very expensive. How many do they expect to produce, maybe 100 units?
BillWojo
This is based on visiting thousands of shops in my career, many that are working on military contracts.
In the case of the 401 plinth, it's a darn bit cheaper to produce a very limited number of them by milling from a solid plate of aluminum than to design and build an injection mold. Even having it sand casted will require an expensive mold and the upfront cost would be very expensive. How many do they expect to produce, maybe 100 units?
BillWojo
Machine from solid, and you can (almost) guarantee a decent part; sand cast, you've got to allow for casting shrinkage far a start, then there's inclusions, porosity, core shift, distortion caused by one side cooling faster than the other, AND you'll have to machine it anyway.