Domodude17
Aluminum
- Joined
- Aug 14, 2017
I'm a VERY novice machinist, I have been setting up my 9A lathe which is my first ever machine. It came with a 3 jaw chuck, but it's got bellmouthed jaws that can't hold anything and has 0.011" of runout. I bought a NOS 6" 4 jaw chuck without a backplate. Since I didn't have a currently working chuck or thread dial, I opted to buy a pre-threaded backplate so I could machine it on the lathe, which I did.
I've been trying to get it level. I have a 3/4" piece of O-1 drill rod that I have been using as a test piece, so it's very round and straight. When I chuck it up, I can get it to 0 runout right at the chuck jaws, but I noticed that if you look further down it looks as if the bar is oscillating, and the TIR increases even if I re-zero the indicator. To me, that seems to indicate that the chuck might be sitting at an angle on the spindle-it does seat against the register. I realize this could be from the bar drooping slightly, but it seems way too excessive and is more than just a couple thou.
However, I realized that I did not machine the surface on the backplate that seats against the register, only the OD and chuck seat. Could this be my source of error, or is what i'm describing a symptom of not having a level bed yet? Theoretically, I should just be able to take the backplate off, put it back on the spindle backwards, and true up the register seating face? Or will I need to redo the chuck register step at the same time as well?
I've been trying to get it level. I have a 3/4" piece of O-1 drill rod that I have been using as a test piece, so it's very round and straight. When I chuck it up, I can get it to 0 runout right at the chuck jaws, but I noticed that if you look further down it looks as if the bar is oscillating, and the TIR increases even if I re-zero the indicator. To me, that seems to indicate that the chuck might be sitting at an angle on the spindle-it does seat against the register. I realize this could be from the bar drooping slightly, but it seems way too excessive and is more than just a couple thou.
However, I realized that I did not machine the surface on the backplate that seats against the register, only the OD and chuck seat. Could this be my source of error, or is what i'm describing a symptom of not having a level bed yet? Theoretically, I should just be able to take the backplate off, put it back on the spindle backwards, and true up the register seating face? Or will I need to redo the chuck register step at the same time as well?