I haven't noticed it before until now; for a year I've been machining parts only 2-3" max for a few thou' and generally have not used the compound feed handle that much. today, I chucked a 4" piece in and turned out the full length of the compound as I wanted a fine feed for the whole length of my piece. I wanted to turn it down .080 in 4 or 5 passes and have a great finish. it's only 3" dia round, 6061 so not expensive if I ruin it.
But as I got about half-way thru and stop to check if I was turning it square to the center, I saw my cut was more than the .020 I started with, it cut about .028. Then I thought, well, I'm ok I might've bumped the cross slide and can get back on spec next pass. So I finish my turning cut and check the end close to the chuck and it's back to the .020 I planned on. scratching head. my ways are really straight (within .0015) and the main coarse feed doesn't so this, just the compound.
I don't understand what I can do to compensate or maybe I need to get a new compound? the cross feed is right on 90deg for it's full travel to the chuck.
thanks for any tips!
But as I got about half-way thru and stop to check if I was turning it square to the center, I saw my cut was more than the .020 I started with, it cut about .028. Then I thought, well, I'm ok I might've bumped the cross slide and can get back on spec next pass. So I finish my turning cut and check the end close to the chuck and it's back to the .020 I planned on. scratching head. my ways are really straight (within .0015) and the main coarse feed doesn't so this, just the compound.
I don't understand what I can do to compensate or maybe I need to get a new compound? the cross feed is right on 90deg for it's full travel to the chuck.
thanks for any tips!