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12-28-2016 Post does not mapped to Knowledge Tree
musicomm
Posts 2
Joined on 12-27-2016

Post #: 1
Post ID: 22902
Reply to: 22902
Micro seiki SX-8000 Air flaoting problem
Hi,
I am an analogue mania so naturally I love turntable.
I have acquired a Microseiki SX-8000 several month before and found it had speed irregularity. I thought first, the motor might be the problem but soon found there were scratch sound on the turntable. When I removed the platter I could see some scratch on the glasses, bottom and top.
I was suspicious that the pump might not supply enough air pressure to lift the heavy platter. But after six month of experiment I found it is not the air pump problem.

After six months of waste of time from wrong diagnosis I now suspicious of leakage of air somewhere.
I studied the structure of the turntable and tried several things I could do to find where it leaks but failed.
The last thing I could think of is the bearing of the turntable. The air must leak through the bearing down to bottom of the bearing. Not to top of the platter or to air suction hole either.
Problem is the bearing looks very complicate and I don't have courage to disassemble it to study.
So I took the turntable with air pump to a technician and he disassembled it but he told me he could not solve the problem. He was the last one I could rely on solving the problem.

Now I have to solve the problem by myself.
I have started searching Google to see any related topic and found this forum is where the most active MS users are
Is there anyone who has experience of solving similar problem of MS SX8000?

Hope to hear your valuable advice.

From Long time annoyed, Kim

12-28-2016 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,547
Joined on 05-28-2004

Post #: 2
Post ID: 22903
Reply to: 22902
Make it clean and wet.
Kim, what I would recommend if to keep presuming that the air pump do not supply enough air flow. We understand that your platter does nor rise high enough and does not clear the glass plates. The only reasons for it would be the air pressure is not sufficient enough for the air discharge you have. So, let (juts for sake of experiment) to increase the air flow unit the plate rise enough to clear the glass platform.  
 
Now we have two possibilities. If you pumping more and more air flow get the state that your platter get a free spinning then you might have a defective pump or air leak. BTW, if everything works fine then this TT needs a remarkably low air flow, you shall hardly feel the flow in the hose but even this shall make the platter rise. I use $20 aquarium air pumps and they do very fine.  
 
The second opposability is a bit uglier and I personally feel that is it what you have. If you pump a lot of air and your platter do not rise then you have something that prevent yours platter to rise. The scratches on the glasses that you report is an indication of dirt that one was between the glass surfaces, so I wonder if that dirt that was there made somewhere that juts blocks the platter free vertical movement? I would serially to investigate this direction.  
 
Regarding the bearing. The bearing in this TT is VERY simple. You need to flip TT and to unscrew a back plate with 6 or 8 screws. The bearing will fall out on the table. The bearing on this TT is not what you think. The 1500-5000 models have a ball under the main shaft that is rolling on the back plate that you just unscrewed. In these TTs you need to lubricate all of it but not in 8000. In the 8000 the rising palter shall decuple the bearing from contact and most of the 8000 do not even have the ball under the shaft. What the 8000 do have is the long cylindrical friction shaft that is very tightly sits in the TT base and into which the palter’s main shaft is inserted. You do want to remove this shaft and lubricate it. I think W40 will do. Make sure that it is absolutely clean and that the female part of the shaft (the indentation on the base) is very clean and lubricated. I presume that it is very dry and dirty and this is something that preclude the platter to rise.  
 
As you clear it I would also buff the glass platform, making sure that scratches borders do not rise over the glass surface.  
 
Rgs, Romy


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
12-28-2016 Post does not mapped to Knowledge Tree
musicomm
Posts 2
Joined on 12-27-2016

Post #: 3
Post ID: 22904
Reply to: 22903
Several things to think about
Hi Romy,
First I want to say thank you for your opinion.
I have read your post several times and I will read it again to understand fully what you mean with my 8000 next to me. You have given me things to think of such as 'dirt that cause the scratch on the glass' 'cleaning the shaft' 'buff the glass platform' etc.
My TT is at the technician's office and I will take it back today.
I will disassemble the main bearing and I might have more questions later.

For the air pump,
There are too many things I can tell about it but it will be too long to write all about it. (You know I have spent six months on the pump)
To make it short, I have five air pumps. MicroSeiki SX-8000 works with and comes with two air pumps as you know.(RV-1090 for air suction and RP-8020 for air bearing)
I bought one extra RV-1090 and later two Aqua pumps. The two Aqua pumps have same capacity as RP-8020. RV-1090 also blows air so it can be used for air bearing but the pressure is much lower than RP-8020.
.
I bought all those three extra pumps thinking air pump might be the problem.
But I decided to cut that out from the possible problem because when the TT is in good mood it works with any pumps. When it is in bad mood it stubbornly resists like a peevish donkey to rotate properly with any pumps. I even combined to pumps to double the pressure or pump output but no difference.
But it turns w/o any blemish when it is in good mood for more than 20 hours but It is not possible go guess what makes it feels good or bad.
This drives me nut.

I even though to remove the air bearing and put a new bearing. But the platter is way to heavy for a conventional bearing and it will be no more Micro seiki sx-8000 w/o air bearing. So I gave up the thought.

I really hope I can solve this problem soon and I believe that there must be some way to solve it.

Thank you again.










12-29-2016 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,547
Joined on 05-28-2004

Post #: 4
Post ID: 22905
Reply to: 22904
That moody turntable
Well, from what you said, if your TT has moods and sometime it works and sometime does not (the platter does not lift up high enough) then the problem is most certainly is not a leak but dirt and a lack of lubrication. You can test the lack of lubrication also by seen test. As the TT is spinning at the cruse speed at 33 rpm and you get rid the belt the planner should continue to spin for at least 4-5 mins. if it sop faster than you have too much friction in your bearing. Do not worry about your pumps. This TT should have incredibly small am out of air flow to make a platter rise. Do not even think that it should have CPAP level blowers. When I try to make my tube that feeds the air suspension to blow on my hand I hardly feel any air flow, so I need to blow in my tang to feel some flow. It is VERY contra-initiative as you feel that such a small air flow and no air pressure of any significant kind would be not enough to raise such a heavy planter. It does to all my surprise.


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
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