First time machining getting chatter

[customchris]

Hello I got a craftsman 12" and I getting a lot of chatter unless I force the cut. Lite cuts look like crap and it chatters bad.. I was turning steal mild. Here is a pic you can see the chatter in the face cut. It was chattering on the side cuts also. If the tool bit did not have a top relief whould that make it chatter?

 

[lens42]

Something is loose. What do you feel when nudge the tool by hand in all directions. Maybe adjust gibs.

 

[Wreck™Wreck]

Procure a piece of wood, a 12" length of common 2 X 4 will work. Place one end of the lumber on the material above the tool(cut a V notch in one end if this makes it easier for you) while the cut is being made, held by hand.
This often reduces the harmonic vibrations that develop during turning operations.

The most rigid lathes that you can buy using high end tooling will chatter depending on the part being turned and the way that it is held.

Report the results here, works a charm for me.

 

[Ken_Shea]

In addition to the above which would also be my first suspect.
The chatter area resembles results from turning extra hard areas that I've seen before, not particularly infrequent in questionable what is it material.
This can be compounded by cutters that are not as sharp as they should be.
Make sure cutter is on center line.

I'd be interested in seeing the cutter if you have the time and knowing the cutter type, size, diameter of material and also RPM, perhaps something will stick out of sorts from that information.

If a small size cutter make sure there is minimal overhang.

Ken

 

[NightWing]

That part doesn't look like steel. More like bronze or a brass alloy. How far from the chuck jaws was the part? Spindle speed?

 

[customchris]

Here is a video of the chatter

 

[dracozny]

What was rattling in the background? It honestly sounds like yo have something loose on the carriage. Outside of that I think you may need to play with the RPM's a bit to find a sweet spot for that material.

 

[seasicksteve]

Can you lock down the apron? Is the part secure in the chuck? Have you checked for looseness in the gibbs on the cross slide and compound?Once the part is chattered up it can be difficult to get rid of the chatter, you might have to try to take enough to get underneath it once you get things squared away. Try playing with the speed and feed a bit, you might benefit from a bit of cutting oil

 

[caster]

I watched the vid, the chatter continued after the tool bit entered the center hole. There must be something else besides the tool cutting making the noise.

 

[NightWing]

OK, after watching the video, that is steel, not bronze or a brass alloy that I first mentioned because of the color.

What appears to be rust on the OD of the workpiece may indicate stock that was left out in the weather for a while. Some materials "age" a bit when exposed to the elements for extended periods of time.

It looks like you are experiencing hard spots in the workpiece which is aggravating the harmonics of the operation. Something appears to be loose, either in the headstock, carriage or compound. Take another cut and try laying your finger against the carriage where it contacts the ways to see if you can detect any movement. Repeat with the compound and compound rest. Of course, do this AWAY from the workpiece.