We purchased a 4" rotary table from Harbor Freight when they had a sale and modified it to be the 4th axis on our cnc micro-mill. To reduce some friction, a $4 thrust bearing was ordered from Mcmaster-Carr and installed just below the rubber motor coupler. The plywood motor mounts are temporary. Once I find a shorter motor shaft coupler, new ones will be made out of aluminum. The table uses a worm gear mechanism which isn't machined very well. There is some backlash, about 1/2degree. I would recommend finding a better rotary table with less backlash. This one was inexpensive so can't really complain about the quality to much.
The stepper motor is a surplus nema23, about 100oz/in, driven by a Microstep driver.
We also purchased a 3" 4-jaw chuck from Little Machine Shop so we can mount odd sized parts to the rotary table.