DirtyDusty
Plastic
- Joined
- Jun 3, 2021
Just started learning how to run a lathe. We have an old msc 13/40 3hp lathe at work, that was just sitting. I ordered a Dorian bxa tool post and some carbide inserts to get started. I have been turning some conveyor shafts, but I am having a few issues.
I am using 1.5 square stock, and turning the ends down to 1.25. One end has a round section 3 long and the other end is 10 long with a keyway. The total shaft length varies depending on conveyor width. The spindle bore is only 1 3/8, so I cant run it through the head stock. I have been using a 4 jaw Chuck and dialing it in a couple of inches from the jaw, indicating off the corners. Then I center drill the end, which was faced off on a mill. Insert a live center and turn down. I start roughing it in with a square insert, .125 doc and .007 feed rate. It goes smooth until I get down to about the 1.4 range and I start getting a lot of vibration, a few inches out. Using about @650 rpms until I get to 1.5 then speed up to @950rpms. At 1.4 I switch over to a tnmg331 and start making .050 passes with a follow rest.
I am having severe vibration and over 10 I am gaining .010 from thr live center to the shoulder. This is on a 30 total length shaft. After reading quite a few posts on here I understand that running from a Chuck to a center isnt ideal, so what would my best approach be? Is the heavy vibration from the set up or normal with that diameter and length?
I am using 1.5 square stock, and turning the ends down to 1.25. One end has a round section 3 long and the other end is 10 long with a keyway. The total shaft length varies depending on conveyor width. The spindle bore is only 1 3/8, so I cant run it through the head stock. I have been using a 4 jaw Chuck and dialing it in a couple of inches from the jaw, indicating off the corners. Then I center drill the end, which was faced off on a mill. Insert a live center and turn down. I start roughing it in with a square insert, .125 doc and .007 feed rate. It goes smooth until I get down to about the 1.4 range and I start getting a lot of vibration, a few inches out. Using about @650 rpms until I get to 1.5 then speed up to @950rpms. At 1.4 I switch over to a tnmg331 and start making .050 passes with a follow rest.
I am having severe vibration and over 10 I am gaining .010 from thr live center to the shoulder. This is on a 30 total length shaft. After reading quite a few posts on here I understand that running from a Chuck to a center isnt ideal, so what would my best approach be? Is the heavy vibration from the set up or normal with that diameter and length?