Jet 16 quill bearing preload?

[mws]

I found a had a little chatter recently and discovered the bearings needed a little tightening up on my Jet 16 quill. Does anyone know what a proper pre-load for these bearings should be? I've been making them a little more than snug, about 10 ft-lbs, since I never load the machine too heavy and this is tight enough to create slight bearing warmth when running.

Thanks

 

[TomS]

I replaced the quill bearings on my Enco round column mill drill about 4 years ago. I couldn't find any information on the web about bearing preload that was relevant and Enco wasn't helpful either. What I did was measure the end play with a DTI and tighten the preload nut until there was zero end play and then tightened it until the lock washer tab lined up with the slot. Not very scientific but it worked for me. The lower bearing does get a bit warm to the touch when I run it for long periods of time at the highest speed.

There's got to be a better method, e.g. such as what you've done with a torque wrench, so it would be interesting to hear from others on how they do it.

Tom S.