Parting Practice Chatter

I was parting just yesterday a 2 1/8" bar of aluminum. I have a killer Aloris parting tool and holder w/ 1/8" replaceable carbide tip. I was running my G0602 on the slowest speed (BTW - not slow enough), I had my drip oiler system set up to keep it cool and the carriage locked down. I was getting a whole lot of chatter!

To better explain why, the bar stock was about 10" long and it was mounted in my 3-jaw chuck. I had a nice, large center in the end with a live center. I had just knurled it with no problem and thought it should be solid enough to part-off, being aluminum and all. After trying different feed rates and checking that everything was as tight as I could get it, I decided that the bar stock had just enough flex under pressure that it will never part smoothly. I had to resort to installing my steady rest, which I should have done from the beginning but thought that I could get away without using it. After that it cut smooth as a warm knife through butter.

Moral of the story is: Keep it short or don't be lazy and use a steady rest.

Rick
 
Very interesting.... Good that you isolated your issue. I'm surprised that was the problem, unless it is masking a less than perfect cutting tool o something? Rigidity never hurt anyway!

Bernie


Sent from my iPad using Tapatalk
 
Fabrickator said:
I was parting just yesterday a 2 1/8" bar of aluminum. I have a killer Aloris parting tool and holder w/ 1/8" replaceable carbide tip. I was running my G0602 on the slowest speed (BTW - not slow enough), I had my drip oiler system set up to keep it cool and the carriage locked down. I was getting a whole lot of chatter!

To better explain why, the bar stock was about 10" long and it was mounted in my 3-jaw chuck. I had a nice, large center in the end with a live center. I had just knurled it with no problem and thought it should be solid enough to part-off, being aluminum and all. After trying different feed rates and checking that everything was as tight as I could get it, I decided that the bar stock had just enough flex under pressure that it will never part smoothly. I had to resort to installing my steady rest, which I should have done from the beginning but thought that I could get away without using it. After that it cut smooth as a warm knife through butter.

Moral of the story is: Keep it short or don't be lazy and use a steady rest.

Rick
Click to expand...


Great Rick- the steady rest is the way to go, but for two reasons.

Obviously it resolved the rigidity issue. But a note here as well- technically we aren't supposed to ever perform parting operations between centers, even if one end is in a chuck.

It may not seem possible, but it compresses the cut enough that the tool can bind and with nowhere to go, you might bend a spindle or throw a part.

So I'm glad you upgraded to the steady rest!

Bernie


Sent from my iPad using Tapatalk
 
Let me second Bernard's suggestion of leaded steel. CRS is not the best material to be learning on.
 
You must log in or register to reply here.
Back
Top