High Precision Bearing
A completely new designed, rigid, close tolerance, high precision bearing for Technics SL-1200 & SL-1210 Turntables.
I have had another set of bearings manufactured which are ready for immediate dispatch. You can order yours online from this page.
The Standard Technics Bearing
This completely new design of bearing for the SL1200 arose from an evaluation of the shortcomings of the present bearing, and the realisation that this bearing could not be effectively improved on by modifying any friction pad or spindle end, owing to a number of factors.
The main spindle is only 7.1mm in diameter and has a separate brass taper piece, which locates the platter. Now this taper component is held in place by a ‘circlip’, which fits into a groove machined into the main shaft where the taper sits, exactly where you do not want any weakening of the shaft.
This groove effectively reduces the diameter of the main shaft to just less than 6mm!!! and more importantly has the far more serious effect of potentially causing micro vibrations at this point which will travel down the shaft and be reflected by any modified rigid pressure pad arrangement, causing harmonics to be generated which will travel back out across the platter to the cartridge resulting in sonic coloration of the replayed sound.
Additionally a second groove is machined into the bottom of the shaft just above where the support ball is located, which produces additional problems of rigidity and sonics.
Further the very light cast aluminium housing of the bearing cannot ever offer the rigidity required for the superior sonics which the excellent Direct Drive Motor is capable of.
The foregoing and the relatively loose fit of the main shaft to the bearing, are the reasons why it was considered necessary to design a completely new bearing assembly, taking advantage of the maximum available envelope afforded by the current motor/coil assembly and which cannot be changed or modified.
The Mike New High Precision Bearing
In order to maximise the length of the bearing consistent with the dictates of engineering physics, and to obtain optimum rigidity of the ‘system” a shaft length of 36mm was chosen together with a diameter of 12.8mm. Consistent with the need to maintain these ideals, the taper has been designed into the shaft as an integral part of it. (no push-fit Brass taper or grooves)
In order to obtain optimum shaft length and at the same time use a ball/pad combination in keeping with the overall design concepts, a 6mm deep counter bore has been cleverly machined into the end of the shaft in which an 8mm Silicon Nitride ball floats. This ball rests on a ground carbide pad. The locating spindle has been made 3mm longer than standard to allow for those people who require to use the thick copper mats and centre clamps now available.
The bearing material is a special sintered bronze and filled with a very thin synthetic oil.
The bearing shaft is fitted to a substantial housing machined from solid brass and which has designed into it a totally sealed oil cavity for the ball/pad assembly. This Oil cavity is filled with a special Synthetic Oil to which a very Extreme Pressure Additive has been added. The top of the bearing contains a shallow oil reserve for occasional re oiling with the much thinner oil.
- The Bearing Housing is machined from a solid billet of machining quality brass bar 65mm dia. by 45mm long.
- The three locating posts on the Bearing Housing have been made as large as practical (allowing for the manufacturing tolerances of the SL1200) so as to provide the largest possible mechanical contact between the housing and the main chassis and also for maximum accuracy of concentricity with the Magnet Rotor and Motor coil assembly to which it attaches.
- The centre column of the Bearing, which fits into the centre of the printed circuit/motor coil assembly, has been made as large as possible for maximum rigidity.
- The bearing bush is made of close sintered bronze impregnated with oil and honed to fit each spindle as a set, to a nominal clearance accuracy of 0.008mm (less than 1/2 of a thousandth of an Inch) There is a procedure to honing sintered bearings A course stone is used on the hone in order to keep the pores of the sintered bearing as open to oil as possible.
- The main shaft/Spindle is 12.9mm in diameter by 39mm long. The 12.9mm diameter was chosen so as to allow for any over tolerances in the nominal 12.7mm (1/2”) bushes.
- The main shaft, record spindle and the locating taper are made from a single piece of M200 Cr-Mo tool steel hardened and gas Nitrided.
- The shaft and Taper are precision ground in a NC grinder to an accuracy of 0.002 TIR.
- After gas nitriding the spindles are polished to a surface finish of 0.4 microns.
- The vertical load of the Platter and associated copper mat (if fitted) is supported by a 8mm dia. Silicon Nitride Ball. This Ball floats in a 6mm deep cylindrical cavity in the end of the shaft. This cavity allows the Ball to locate within the Honed Bearing for absolute maximum rigidity, removing any possible resonance problems. This design also allows for the maximum length of bearing.
- The Silicon Nitride Ball rests on a 3mm thick solid carbide pad. These components are housed in a large sealed oil well in the bottom of the bearing housing. The well is filled with very Extreme Pressure Synthetic Oil.
- The record locating Spindle has been made 3mm longer to cater for those people who wish to use the increasingly accepted copper mats with 200gm vinyl and center clamps.
- These Bearings are totally made in Australia by myself with the main spindle being supplied by a high precision tool and gauge manufacturer who is NATA approved and a NCS International-Certified-Quality company for Aero Space and Medical Work.
- Technics SL-1200 Mk2
- Technics SL-1200 M3D
- Technics SL-1200 Mk5
- Technics SL-1200 LTD
- Technics SL-1200 GLD
- Technics SL-1210 Mk2
- Technics SL-1210 M3D
- Technics SL-1210 Mk5
- Technics SL-1210 M5G
The Mike New High Precision Bearing can be installed in under an hour with a screwdriver and some side-cutters, or even some nail clippers.
There are no options for this product.
Buy It Now
- 1x Mike New High Precision Bearing
- 1x syringe of our super slippery oil
including worldwide shipping