DIY platter bearing
- Thread starter cougarnut
- Start date
hi, i think that the design of a bearing is really very simple, but actually *making* one needs a great deal of precision.
Not a drawing, sorry, just a basic sketch of a pretty typical layout of Scheu/Teres type, which is really a variation on the ancient Garrard/Thorens design.
The large bearing surface provides some oil drag with a ball bearing/thrust pad at the bottom. An oil reservoir at the bottom, too.
Its sucess depends largely upon the quality and finish of the machining so if I were making one I would make the bottom removable, like the Garrard 401, simply because it's easier to lap a through hole than a blind one. I also think that unless you have access to some very good equipment (I don't!) then it will be a case of very carefully lapping the bore against go/no go plugs and then slowly, slowly finishing the shaft to fit.
regards, jeff
Not a drawing, sorry, just a basic sketch of a pretty typical layout of Scheu/Teres type, which is really a variation on the ancient Garrard/Thorens design.
The large bearing surface provides some oil drag with a ball bearing/thrust pad at the bottom. An oil reservoir at the bottom, too.
Its sucess depends largely upon the quality and finish of the machining so if I were making one I would make the bottom removable, like the Garrard 401, simply because it's easier to lap a through hole than a blind one. I also think that unless you have access to some very good equipment (I don't!) then it will be a case of very carefully lapping the bore against go/no go plugs and then slowly, slowly finishing the shaft to fit.
regards, jeff
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Hi, didn't know the Scheu was the other way up. I guess that still applies for the Teres/Garrard type, though the Garrard uses a domed end rather than a separate ball and has a male taper at the top of the shaft.
Even so, they're simple things, just dependant on very accurate machining and finishing
regards, jeff
Even so, they're simple things, just dependant on very accurate machining and finishing
regards, jeff
Jeff.. your drawing is appx. correct forr the Teres bearing....
except there is a wider pocket in the middle 1/3 of the bushing.. this reduces drag friction and also serves as an oil reservoir fo rhte upper part.......
Cougarnut....
I have made the Teres bearing, - but I don't have access to the drawings at the moment......they were public on Teresaudio.com until sometime 2003, - and I later exchanged mails with Tom Machris, one of the original Teres builders...
The diameter of the spindle in a revised version was 20 mm, - spindle length into bearing appx 50 mm.
A good bearing needs to be machined and polished to an accuracy of 3-5 microns.....0r 0.005 mm...
Jeff....
something was rumbling in the back of my head....
I just checked out the mod's you made as well as the original #26...
except there is a wider pocket in the middle 1/3 of the bushing.. this reduces drag friction and also serves as an oil reservoir fo rhte upper part.......
Cougarnut....
I have made the Teres bearing, - but I don't have access to the drawings at the moment......they were public on Teresaudio.com until sometime 2003, - and I later exchanged mails with Tom Machris, one of the original Teres builders...
The diameter of the spindle in a revised version was 20 mm, - spindle length into bearing appx 50 mm.
A good bearing needs to be machined and polished to an accuracy of 3-5 microns.....0r 0.005 mm...
Jeff....
something was rumbling in the back of my head....
I just checked out the mod's you made as well as the original #26...
I made the bearing two years ago,.. on a standard good quality manual lathe, with very careful measurements going along, using micrometers instead of calipers...I happen to have access to a fairly good workshop outside normal working hours..
I later made another one using a piece of a very high precision 20mm hydraulic piston rod and what we call a precision "brotsh" (reamer ??) for the housing.... both came out quite well, with a tolerance of appx 5 microns...I still have a little fine polishing to do, - using 1-2 micron papers....
Unfortunately other events stole my spare time, so the bearings are still happily residing in a drawer in my office...
Hopefully I will be able to complete the "thing" during the winter, as at least some of the major events governing my spare time has died out quietly.....................
I later made another one using a piece of a very high precision 20mm hydraulic piston rod and what we call a precision "brotsh" (reamer ??) for the housing.... both came out quite well, with a tolerance of appx 5 microns...I still have a little fine polishing to do, - using 1-2 micron papers....
Unfortunately other events stole my spare time, so the bearings are still happily residing in a drawer in my office...
Hopefully I will be able to complete the "thing" during the winter, as at least some of the major events governing my spare time has died out quietly.....................
Come to think of it....
a couple of years ago... 2003 I think, someone posted an idea for a bearing using a hydraulic valve as the basis for a bearing..
ready made high precision... just remove the O-ring seals...
I tried to locate such a valve, but did not succeed..
anyone here into hydraulics that could find a name and number???
EDIT:
Found it! Dice45 in post # 29!
http://www.diyaudio.com/forums/showthread.php?threadid=4578&perpage=10&highlight=&pagenumber=3
Actually-- it all started many years ago, when I set out to make the "Platine Verdier" as published in "l'Audiophile".....I then used an intermediate shift axle from a Ford Transit gearbox..!!!
The project halted , because I could not find ring magnets strong enough to hold the upper bearing half and platter...............
at least not for an acceptable price!
a couple of years ago... 2003 I think, someone posted an idea for a bearing using a hydraulic valve as the basis for a bearing..
ready made high precision... just remove the O-ring seals...
I tried to locate such a valve, but did not succeed..
anyone here into hydraulics that could find a name and number???
EDIT:
Found it! Dice45 in post # 29!
http://www.diyaudio.com/forums/showthread.php?threadid=4578&perpage=10&highlight=&pagenumber=3
Actually-- it all started many years ago, when I set out to make the "Platine Verdier" as published in "l'Audiophile".....I then used an intermediate shift axle from a Ford Transit gearbox..!!!
The project halted , because I could not find ring magnets strong enough to hold the upper bearing half and platter...............
at least not for an acceptable price!
How about a fluid dynamic bearing? These are used for low-noise fans and hard drive motors, and if the right type could be found (something that is designed for low rpm operation), should be extremely quiet.
In 1985, Kenwood (Trio) made a DD turntable called the KP-1100 that had a platter spindle similar in concept to a modern fluid dynamic bearing. The spindle had a herringbone pattern embossed on the shaft surface, and was located within an oil well. The rotation of the spindle caused the herringbone pattern to function rather like an Archimedes pump, and this circulated and pressurized the oil, and the pressurized oil film kept the spindle aligned accurately without any direct contact with the bearing housing.
Link here (text in Japanese):
http://www.niji.or.jp/home/k-nisi/kp-1100.htm
hth, jonathan carr
In 1985, Kenwood (Trio) made a DD turntable called the KP-1100 that had a platter spindle similar in concept to a modern fluid dynamic bearing. The spindle had a herringbone pattern embossed on the shaft surface, and was located within an oil well. The rotation of the spindle caused the herringbone pattern to function rather like an Archimedes pump, and this circulated and pressurized the oil, and the pressurized oil film kept the spindle aligned accurately without any direct contact with the bearing housing.
Link here (text in Japanese):
http://www.niji.or.jp/home/k-nisi/kp-1100.htm
hth, jonathan carr
