VPI TNT Bearing question

Yes, the TNT non-inverted Mk5 bearing is a significant upgrade over the previous generations. The older TNT bearings were made out of aluminum and were attached using 3 small bolts. The Mk5 bearing is made out of stainless steel with MUCH greater mass. The bearing is mechanically coupled to the plinth using a very fine threaded 3 inch stainless steel collar which secures the bearing much better than the previous versions. In addition, the Mk5 bearing has much thicker Rulon (sp?) bearing collar sleeves which are made to a higher tolerance.

Some Mk5 bearings do not come with the 3 inch threaded mounting collar but come with a traditional nut and bolt combination, although not as attractive, performance wise they are the same. I own three examples of the TNT bearing. TNT Mk3.5, TNT Mk5 with nut and bolt, and a Mk5 with the 3 inch collar. The end result with the Mk5 bearing is a quieter bearing with improved micro detail and dynamics

VPI no longer stocks the MK5 bearing, therefore finding a bearing will be your challenge. The Mk5 bearing is a drop in replacement for older TNT bearing. The TNT Mk5 inverted, Mk6 and HRX inverted bearing require a larger bearing hole, therefore, older TNT tables will require modification. I am not sure if the new inverted Classic bearing will fit a TNT. Hope this helps

That bearing, and its companion MKV platter is what I have on my TNT. According to Mike at VPI: "they are as good as anything we have ever made; including the Super Platter".

Totally agree 100%. I used both the Super platter and the MkV platter. Kept the MkV platter and returned the Super Plater.

Please allow to offer some clarification. The MkV mechanical coupling is vastly superior to that of the 3 bolt coupling. VPI also changed to this type/method of coupling the newer JMW Memorial tone arm bearing; it is basically a mini MKV setup.

My only concern with modifying an older TNT bearing to utilize a single bolt coupling method as deployed in the MkV is that the older bearings are aluminum and I am not sure if your could get the appropriate torque without stripping the soft aluminum threads. If you are interested in my back up MkV bearing, send me a pm.

I am not a machinist, but I can surely appreciate the precision required to make a bearing that must run true along with providing a 90 degree platform for the platter to rest. How much would a machinist charge for a stainless steel bearing similar to that of the TNT Mark V?

Thanks Ketchup. You have confirmed my suspicion that it sounds easier than it is…… plus you are taking a gamble that it will work and sound good. If I had machining skills and access to equipment, it would be a fun project to attempt with the only real cost being materials. I see a lot of threads on DIY plinths, outboard tone arm mounts, motor drives etc, but very few are attempting their own bearing and platter assembly (except for Dgarretson)