Rotary Table play

[bmurph]

I have a 4" round of 4140 on a 4" rotary table, and when cutting the outside of the round the tables backlash causes a lot of noise, and vibration, and I think it's dulling the bits very fast. So I try to tighten the screw on the side that holds the table, but it's just not enough. Do I just gotta get a 6" table, or is there better quality out there?

[HuFlungDung]

That sounds like a pretty big part for a tiny table. You might have to take the table apart and find out if there is any way to reduce the backlash: reduce the end clearance between the worm and the housing, or move the worm eccentric so that the worm meshes closer to the worm gear. But bear in mind that a tiny table is going to exhibit more flexure than a bigger one, no matter how much you try to reduce the backlash.

[Delw]

Also check the lockdown system to make sure is really locking it down tight

[hopefuldave]

...And be sure you're not trying to climb mill - table rotation should move the work into the cutting edge (i.e. cutting on an outside diameter, if the spindle's clockwise from above, the table turns clockwise too - on an inside diameter the table would turn anticlockwise) - this ensures that the worm and wheel stay constantly loaded to take up the backlash.

Unfortunately the surface finish won't be as good as climb-milled *on a rigid setup*, but it sounds like it should be an improvement on what you're getting?

Just my ha'pennorth,
Dave H.