Pictures regarding polished main bearings....

Vinyl Asylum

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For those of you that have followed my Rek O Kut projects you know that I found micropolishing the main bearings to dramatically improve bass response, low level detail retrieval and reduce the noise floor. These are all very good things for an idler project.
Here are some pictures for you to inspect.
Picture one is two Rek O Kut main bearings. The one on the back is a stock ROK LP-34 I just purchased a week or two ago. It shows an actual wear depression from the ball that rides between the bearing housing and the thrust surface of this steel bearing.
You can clearly see the natural state of the wear depression in the linked photograph. This will be machined down to flat and level and micropolished for my next project.
The platter in the foreground is the LP-743 which I am using for my RCM at this time. This was micropolished about a year ago.
You should also be able to see the very precise machining on the bearing in the back picture. It is superbly machined however it is unpolished.
The closer platter has a micropolished bearing.
To accomplish the polishing I removed the bearing by pressing it out of the platter. Then the bearing must be measured from top to bottom to find the lowest point. Then go back and polish the main bearing to bring the entire surface to the measurement of the low point.
This removes just enough material to get the surface polished and completely straight. You do not want to overpolish or other sonic nasties might intrude on your soundfield.
The polishing was accomplished by turning the bearing at 600 rpm in a lathe and running a polishing rig along the bearing running at 3k rpm. It requires just 20 minutes to get to the state you see here and much of this time is spent measuring.
The thrust plate is micropolished to a high luster.
Then drop in a silicone nitride ball from McMaster.com or a similar supplier and be ready to say oh my gawd.....
The sound is simply stunning from this simple tweak. I have more photos for you if you want them. Send me an email to jim_howard_pdx@yahoo.com for more details.
Cheers!

http://i10.photobucket.com/albums/a150/tubesforever/Idler Project/pollishedbearings005.jpg (Open in New Window)

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Michael Percy Audio

Topic - Pictures regarding polished main bearings.... - tubesforever 20:49:32 04/12/07 (4)

How do you measure? - Plinko 13:40:21 04/13/07 (1)

Just a common caliper guage with a dial indicator for 10 thousands - tubesforever 08:50:36 04/14/07 (0)

Re: Pictures regarding polished main bearings.... - robertkeir 09:47:38 04/13/07 (1)

Well when it comes to bass I can be very critical.... - tubesforever 10:41:15 04/13/07 (0)

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