Turning Archive 2006
Phil Joines Krum, Tx.
>The pic is the live center that comes with the Jet mini lathe disassembled.
It shows the Morse adapter, the inside of the centerís nose, the original bearing and a replacement bearing.
The original bearing has a metal shield on the tailstock side but the headstock side is open. Itís marked NTN Taiwan 60022. The second bearing is the replacement, obtained from a local supplier, itís an MRC (France) part #102KSZZ itís sealed on both sides. The cost was $21.32. The metal "shield" won't keep fine dust out.
Itís fairly easy to tell when one of these is going bad. With the adapter held motionless try to spin the nose. If it feels bumpy or as in my case wonít turn at all the bearing needs to be replaced. The cause of the failure is the type of bearing used. Itís open on one side allowing dust to enter. I had already cleaned most of the crud out before the pic was taken. The dust hardens the grease and packs the space between the balls. I figured a replacement from Jet would be the same type with the same problem.
To disassemble I held the nose piece in one hand with the adapter pointed down over a table. A piece of 1/4Ē steel rod was inserted into the open nose at an angle so it rested on the end of the adapter. Using a 12oz hammer and light taps both the bearing and adapter where knocked out. In my case the parts came apart with out any trouble but it the fit had been tighter the rod could have been moved from side to side to press the bearing out evenly. I used my pen press to reassemble it. If you need to replace yours just take the old one to a bearing shop and ask for a double sealed replacement. There are lots of good ones out there.
This is a simple repair and the replacement should last until the lathe wears out.