Thanks for your help. Your threads are very informative and they helped me decide to buy these machines, plus a few other little tools I must admit. Wife wasn't too happy, but I feel it's money well spent.
I noticed my lathe is standing taller than yours by an inch or two. Maybe if I shorten the bolts to lower the lathe, it will help reduce some vibration? When I attach the 8" 4 jaw chuck, the vibration is reduced significantly. I hate using the 4 jaw chuck though, takes forever to center the piece. I will definitely try to make 4 solid mounts like you did. Hopefully that will do the trick.
No problem, that's why I post the threads. Yeah I've been known to help people spend their money. Don't tell your while who I am though.
Generally it's not a good idea to lift a lathe or mill high off the ground just using the length of studs. Like my mill, I didn't like how low it sat so instead of jacking it up with the leveling pads, I built a riser base for it.
I was taught to set spindle centerline you your elbow height. Everyone has their own preference but this works very well for me. That way it's no so low where you are bending over constantly but still high enough so you can get an aerial view of the workpiece.
I was curious so I placed a nickel on my headstock, I ran it in every gear & the nickel doesn't move at all. Take your 3-jaw chuck off & test again. If it runs smooth, check the runout on the body of your chuck.
As for indicating with a 4 jaw, lots of guys use dial indicators cause it has a larger face so it's easier to read. I use the same, I use a .001" dial indicator w/ 1/2" travel. If I really need high precision then I'll use a test indicator but usually not needed, the thou resolution is good enough. Unless you're making parts for NASA, a DTI is just going to mess with your head & make you chase the needle around trying to get it to move as least as possible.
I place my indicator at the 9 o'clock position, easy to read cause the face is right in front of you. Tighten your highs, loosen your lows. If you have a part that has a poor surface finish or not very round so you indicator bounces all over the place, just 4 point it, or in other words just indicate at every jaw position.