There is plenty known about what to look for when investigation the of the Bearing Housing Parts are being exposed.
Always best to keep a keen eye for discovering minute gold coloured dust, this is the softer material from the Sintered Bronze Bush having been separated from Spindle Metal in contact with the Bush, it is the occurrence, that substantially contributes to eccentric rotation, speed stability issues and an amplified platter run out at the rim. .
The Sump Seal will be under suspicion for not being able to retain a Low Viscosity Lubricant, having a alternate ' O ' or ' X ' Ring to be the replacement Part will assist with creating a seal that works. I like the ' X ' Seal, as it supplies two lines of contact for what is a low pressure seal.
My engineering friend has informed me, that a correctly designed Journal Bearing with all metal parts will be as quiet in operation as one with non metal parts used in the same design Journal Bearing.
The challenge is creating a design that is able to have non contact between metal parts. The slow rotation and non pressurised design used typically on a TT Bearing makes this very very difficult to achieve.
A Lubricant Filled Bearing Housing will remain subjected to Boundary Effect issue, where when Metal on Metal is to occur, this becomes the cause of Friction and Drag and in certain cases a sticking of the Parts. The use of a design that removed Metal on Metal is known throughout industries for the benefits on offer.
This is where certain designs of Thermoplastics have proven their value in all areas of industry, even in the low speed rotation Journal Bearing, as the Thermoplastic when produced to a particular compound and hardness, does not generate the same effect as a Metal when the rotating spindle makes a contact with the non metal part.
Well before I was showing an interest in separating Metal on Metal in an audio related interest, another Interest I was involved in during my late teen' years was using Teflon to separate Metal on Metal and substantially reduce drag and improve the user interface.
Over a few years of the success at a competitive level the designs were having, not many of the items being produced for competitive level activity were without Teflon or some other equivalent used for separation, the cat was well and truly out of the bag.
More importantly, an alternate lubricating method to negate the use of a Separation was or has been discovered, but such designs are superseded to day for a completely different mechanical design.
With such a background, I have made it known before, I was Instrumental in encouraging a friend quite into the Lenco TT, to have produced a Bespoke Platter Spindle Design to go with a replacement Bearing Design that was incorporating no Metal on Metal as the fundamental design.
The Spindle Design for the Bearing was suggested to be in keeping with the overall Bearing Design. The Spindle Design was Bespoke in itself for a few reasons.
The Spindle was increased in overall length to the typical extended length option, with the intention to minimise the effects of Runout at the Platters Rim.
The Spindle was a design which was offering the option for using Two Different Materials. Where the lower Spindle was a metal section that was within the Bearing Housing. The Upper Spindle Section was able to have different material used that are in contact with the Platter.
This option of choosing the material to be in contact with the Platter was proven to be quite beneficial through trialling a selection of materials to come into contact with the Platter. Change to the levels of noise detected using a Stethoscope has occurred, where it is clearly understood which materials used were influential on reducing the noise being transferred into the TT's structure.
Non Metal Interfaces used at the Spindle / Patter interface were showing superior influences on noise transfer over metal.
My take on it was to extend the use of Wood Type to a Panzerholz type wood, as it is engineered as a design and will be more stable in use than an African Blackwood.
Panzerholz would have properties that assist with it to be closer to the stability on offer from a Metal Part.
