[SteevA]

Or, in other words; my turntable has sprung a leak, again.

The first damping fluid cup mechanism developed a leak pretty early on.  The leak was not great and only got so far as forming a puddle of fluid on top to the adjustment knob before the whole damping cup mechanism was replaced.

After initial adjustment over a week or so the replacement was left alone and has been fine for the last couple of months - but then I decided to wind the adjuster knob up by 360° to see what difference that made.  After a few days I decided to wind it back down again, having decided that the resultant sound lacked a little vitality.  That was about 5 days ago.

This morning I noticed a drip on the bottom of the adjuster knob so the new one is now leaking worse than the original (although I still got to it before anything actually landed on the shelf).  Has anyone else with a Versalex experienced this leaking?

It still sounds good though and no doubt another new cup mechanism will be forthcoming.

Steve

[Erocka2000]

I'm sorry to hear about your troubles.  I wonder if it's some sort of design flaw in the new arm that will be revised.  I've only seen the Versalex at my dealer's, but it wasn't yet set-up.  Hopefully yours will be fixed asap. 

[SteevA]

It might be a design flaw.  It could also be a manufacturing defect, perhaps the bore for the level adjustment piston has not been finished smoothly.

It might also be a poor choice of O ring quality, either in the original specification or at the time of manufacture.

I am at present suspecting that it needs better O rings but when the new cup mechanism arrives I will probably pull either the old one, or the new one, apart and check that out.  I may also try to source some better quality O rings once I know the correct sizes.

The Versalex might become the only turntable on the market that has to be sold with a drip tray.

Steve

[roscoeiii]

No the Townshend Rock could use a drip tray too...

[SteevA]

It turns out that I am really privileged to have had the only two units on the planet that have so far leaked.  Apparently they were from the very first batch.  Replacements are on order from Opera.

Still not sure of the cause but the O rings are still looking like the problem.  It might be that there is a reaction going on between the silicone fluid and the rubber.

I found this on Wikipedia:
“Swelling by contact with a low viscosity fluid causes an increase in dimensions, and also lowers the tensile strength of the rubber” under the O rings entry.

Steve

[SteevA]

Actually that doesn't apply since it is a high viscosity fluid we are dealing with.

[SteevA]

The leaking has now stopped, or appears to have, under its own accord.  But I won’t temp fate by doing any further adjustments (not needed anyway).

I have found out that a lubricant is applied to the O rings when it is assembled.  Many moons ago I was warned about some petrochemical based lubricants damaging rubber seals.  I just wish I remembered the details but I begin to suspect that it might be the lubricant rather than the silicone fluid that is causing problems.

When the new cup mechanism arrives I think I will not rely on conjecture but take it out to a seal specialist, along with the silicone fluid, and see if I can get the best O rings for the job and a lubricant suitable for those O rings.  It look pretty easy to take apart.  I have avoided this so far but having now had two fail I think I have earned the right to do so.

Steve

[SteevA]

I am advised that I am, after all, not the only one to have this issue and that the cause of the problem has been found.

It appears that one of my original suppositions, "perhaps the bore for the level adjustment piston has not been finished smoothly", has been found to be the culprit and some new and improved versions have been manufactured.

I still think, when it arrives, I will take the new one apart and check it out before adding any goo.  Not sure about trying to upgrade the O rings if the problem was only a poor bore finish, but we shall see.

Steve

[SteveFord]

Good call, it sounds like the rough bore was tearing up the seal.
A good lubricant might be the white synthetic grease that they include with Brembo brake rebuild kits which I suspect is the same stuff as dielectric grease; it has the same appearance and texture.

[SteevA]

Well, the third cup is in place.

I decided not to take the new one apart since, if it started leaking again, the fact I had taken it apart would leave a convenient out.

So I took the old one apart.



There is no obvious damage to the O rings and the bore feels smooth to the touch so, for me, the jury is still out as to the cause.  Whatever the problem is, it is managing to let fluid past two O rings.

The new one has been tested for a few days but the last one only developed problems after a month sitting without adjustment then being adjusted.  I will therefore do the same to the new one.

Steve

[doug s.]

not sure what those o-rings are made of, but if they are not made of viton, you might wanna replace 'em w/some that are...

doug s.

[SteevA]

They have apparently assured themselves that the O ring material is OK - But I shall ask about that anyway.

I understand viton is a brand name - what is the actual material that is required?

Counter to this I found the following:

"High Viscosity Silicone Damping Fluids are particularly effective for use in instruments and gauge that will operate in a wide service temperature range (-40°C to 200°C). Silicone fluids are hydrophobic and prevent humidity from entering the gauge/instrument housing. This is very important. At low temperatures, water condensation can freeze and cause damage to the sensitive parts within the gauge/instrument housing. Ultimately, Silicone Damping Fluids will extend the service life of the equipment that it fills and provide more accurate readings even in the harshest of conditions.

Properties:

•Dampen vibration in gauges, instruments, meters and avionic instruments
•Protects internal components against vibration, freezing and corrosion.
•Extends service life of gauges, instruments, meters and avionic instruments.
•Wide service temperature range
•Low viscosity change at temperature (low V.T.C.)
•Inert to virtually all o-rings, gaskets, seals and valves *
•High Dielectric Strength
*not recommended for silicone rubber due to possibility of swelling"

Which would tend to indicate the damping fluid is not likely to damage the O rings.


Steve

[doug s.]

viton is the material; whether or not it's also the brand, i do not know...

doug s.