@best-groove Thank You for showing the Image of the Stator Housing Bowl.
I have been working with a few Brands of Japanese Vintage DD TT's and have the intention to carry out modifications, where the use a modern material to be used an alternative for the Sacrificial Parts from the Platter Spindle Bearing Assembly.
At the same time of carrying out an investigation, I check the Stator Bowl to see if there is a likely risk of flexion developing and causing Vertical Axis Run Out.
I have a between two an three models of the ones being worked on, the intention is to undertake tests of the 'modified' vs 'used but original spec'.
This as a modification method is already underway between a small group on the Sony TTS 8000, and is one seen adopted by some who offer Vintage equipment as their own products.
In my view the Vintage DD TT's in general have got the Speed Stability nailed, especially when Quartz controlled, the electronics are a concern, but many buy into the TT, accepting the risks.
There are many methods for Vintage TT's, that are seen for the mounting of the TT, the usual considerations are, use original Plinth, use a new material and design concept, as well as mount the TT 'in a Plinth/No Plinth. Obviously the 'no plinth' introduces new considerations for mounting the Tonearm.
The age of the Bearing, Historical Rotations (usually unknown), Condition of the Bearing, are the most commonly overlooked area where a concerning issue might be present. A squirt of oil down a shaft is a real gamble, if thought of as the only requirement. For my sins, I can't rest with this as the only method, the idea that a expensive Cart' is working in conjunction with a non optimised Bearing Assembly leaves myself unrestful.
Looking at the JVC Bowl Image, the material looks like it might be the most substantial gauge of metal used on any TT from this era, the Mounting Rim and Walls are looking like they are able to maintain a very rigid coupling to the Chassis and not yield when exertion through operation is met.
As a guess, I would expect a very low concern for a Vertical Axis Run Out occurring and if need be, a very simple measure needed to improve the condition if present.
Has anybody got any knowledge if this TT has been produced as a Kaneta Method.
I now have a friend to produce the Kaneta Design for the SP10 MkII, the Bowl is to be very tight tolerance embedded into Densified Wood, to reduce the Vertical Axis Run Out, and hopefully leave any concerns to within the assembly within the Bearing Housing.
I am over the moon as I have been knocking on the doors of two friends with this method as an idea for quite some time.
Both friends producers of Tonearms and are also SP10 MkII users, these type of undertakings are best left to those who are adept with correct skills.
The friend to produce the Kaneta Design, has taken the idea a stage further, where there is to be a Thermoplastic Platter produced, with a rim design to lower the centre of gravity and increase inertia. The rim design will also incorporate a design to enable additional methods to add weight and further increase inertia.
The other friend sees their work heading toward the SP10 MkII Platter Spindle Bearing, and a design is on the table an to be imminently produced.
It is time to get the two talking again, to see if an agreement can be come to, to allow the Modified Bearing Designs New Bowl, to be mountable into the Kaneta Design Plinth.
This will be quite a change over the original, and also allow the Thermoplastic Platter to be used in both the Kaneta Design configurations.