Originally Posted by
Steve Allen
Picking up on what Pete has mentioned regarding the ‘O’ Rings, I raised this topic with him as a concern for users in the medium/longer term of ownership. What users need to be aware of is the Rings are being deployed to perform a function they were not designed for, the Rings typically are a seal for fluid and air, and when installed sit in a groove to prevent the Ring from moving, but more importantly to control the deformation of the Ring cross section to ensure the Ring ‘seals’ over a reasonable length of time.
Stating the obvious, all Rings will fail at some point; however, users should understand the failure mode process to avoid potential damage to their turntable.
All Rings degrade from day 1 of usage, what drives the degradation is the environment they are working in i.e. highly corrosive fluid, temperature, etc. Within a relatively short space of time, the Rings will ‘set’ but still function (seal) which is why the groove housing the Ring is so important.
The Pylon Rings will also ‘set’ but will still function, however, the next stage of Ring degradation is to go brittle/hard and then snap, and that is the concern I have, how long will it be before the Rings reach the point when failure is imminent?
I notice in some of the earlier posts that some owners preferred to leave the suspension covers off as they liked the ‘industrial’ element of the design, personally, I would encourage owners to leave the covers on, the reason being dust, and UV will accelerate Ring degradation.
I am not criticising Pete’s design (I purchased a set for myself) but merely wish to make owners aware that maintenance/servicing is required on a regular basis to prevent a disaster. I would suggest that every 3 months (minimum) compliance of the Rings are checked, if they have gone hard, replacement of all the Rings should be done ASAP, as the rotational torque (wow and flutter) coupled with the mass of the sub-chassis will likely snap the Rings in the horizontal plane!!!
I have suggested to Pete that it may be worth Blue Point conducting some trials with higher spec Rings to minimise the risk of a failure, IMHO, the increased costs of higher specification Rings would be a price worth paying, aerospace quality Rings is what I would be considering as an alternative.
Finally, Pete’s design is not flawed, SME have exactly the same problem with their turntables, which is probably why they use a very expensive Ring material for their ‘pylon’ which I believe is reinforced through the centre of the Ring with fibre.
I hope this helps?