Vertex Rotary Table

[rogerl]

I have been thinking about buying a rotary table for a while. I have found a used one listed and I am wondering what should I look for to determine if it is good or worn out? How much back lash should there be in the dial? I need to make sure that the rotation lock handle locks the spindle. Could the bearings be bad?
Any information would be great.

Roger L

 

[Lo-Fi]

Stefan has an excellent series showing internal details. It's not the type of tool that's liable to have seen super heavy use, so just check the basics and go for it if it looks and feels good. Wearing out the table bearing surfaces would take quite a heroic effort, table locks are super simple regardless, backlash can be described as "a little, but not too much". If it turns smoothly, there's not half a turn of backlash and the handle isn't bent, you're probably good to go.

 

[Bob Korves]

Backlash always needs to be dealt with if you are looking for accuracy. It is an important issue for machinists. Make all your settings (and starts and stops) in the same direction (usually the tightening direction, usually clockwise unless otherwise required, on a rotary table.) Lock the RT down before making stationary cuts, always). You will not get good results when there is any gear mesh unless you do so. This is a basic rule on all precision moves when backlash is involved. If you need to machine while turning the table, close the lock down gently enough to turn the table but stiff enough to stop the table from bouncing back and forth from the slack of the mesh, which will hurt both the accuracy and the finish.

 

[pontiac428]

Most RTs have a backlash adjustment. Bearings are easy; I replaced the aging Japanese bearings in my RT with NOS German bearings off ebay for $25 (not that they would wear out on a hand cranked device, just look how long taper bearings last in pinions or wheel hubs). Unless the thing is wonky, the cleanup and tuning should get the result you want.

 

[rogerl]

Thank you for all of the good information. From watching the video it looks like there are no bearings inside the unit. All of the surfaces are machined so if any of the surfaces are worn it would be bad. It is good to see the worm gear is adjustable.

Thanks Again.
Roger L