First of all, leave about 0.15mm of margin for rough machining of the hole, clean the guide rail of the machine tool and add lubricating oil to the guide rail. Loosen the locking screw of the small carriage and rotate it at an angle of 1°, and then lock the screw, and then return the small carriage a few more times and then return to zero, the purpose is to eliminate the screw clearance.
Change the inner hole knife of the fine car, pay attention to ensure that the fine turning tool is sharp enough, otherwise the phenomenon of the knife will affect the machining accuracy, first use the large carriage plate and the middle carriage to try to cut a knife, the middle carriage does not move and the tool does not move the original knife to return to the orifice. Measure how much margin is left after the test cutting, no matter what measuring tools you use, calipers, micrometers, and inner diameter dial gauges are at your disposal.
The rotation angle of the small carriage is 1°, and the large pallet is moved forward by 50mm, which is 0.8276mm!
The middle carriage does not move, and the small carriage moves forward by 50mm to feed 0.8726mm
Moving 1mm means getting 0.0175mm
Moving 0.05mm means entering 0.0008mm