# First time machining  getting chatter



## customchris (Feb 14, 2015)

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?


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## lens42 (Feb 15, 2015)

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


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## Wreck™Wreck (Feb 15, 2015)

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.


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## Ken_Shea (Feb 15, 2015)

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


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## NightWing (Feb 15, 2015)

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?


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## customchris (Feb 16, 2015)

Here is a video of the chatter


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## dracozny (Feb 16, 2015)

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.


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## seasicksteve (Feb 16, 2015)

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


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## caster (Feb 16, 2015)

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.


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## NightWing (Feb 16, 2015)

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.


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## customchris (Feb 16, 2015)

Thanks for all the help... the vibration noise is the cover on the top of the machine.. it is metal on metal.. It makes alot of noise I will try some rubber in between them.


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## mikey (Feb 16, 2015)

Chris, facing is typically done with the side of the tool very near the tip but not with the point of the tip itself. Your tool looks like it has rounded flanks and no top rake; I cannot tell what the side relief looks like.  I suspect the way it is ground and the way you are using it is contributing to your problem. If you re-grind the tool so it has a 7-8 degree clearance angle under the side edge it will work better. If you can learn to grind some side rake - maybe 8-10 degrees - it will cut even better. Add 5-10 degrees of back rake and it will focus the cutting forces near the tip and the tool will cut much more easily. Angle the tool (turn the tool post) so that you are cutting with the left side of the tool, up near the tip. This is how a facing cut is typically done with a single point tool and it should work much better for you.


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## seasicksteve (Feb 16, 2015)

Here is a pic that kinda illustrates the previous post


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## Ken_Shea (Feb 16, 2015)

Mikey's advice is sound, a smaller cutter radius might be a big help .


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## Bill C. (Feb 16, 2015)

customchris said:


> Here is a video of the chatter



Can you lock your carriage?  The outer diameter looks good.  But as the tool gets closer to the center the RPM will slow down.  If I was doing the machining I would speed the RPM's up to the next speed and use cutting fluid or coolant.  The feed looks good.  From your video the rattle sounds to me gear train wear,  some lathes are just noisey.   But I am confused why the material appears to be chipping on you.


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## customchris (Feb 16, 2015)

It was already chipped up. It was a old junk that I had laying around.


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## atunguyd (Feb 17, 2015)

Is it just! Of ate those chips coming of a dark blue? From my understanding that indicates SFM too fart for HSS does it not?


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## dracozny (Feb 17, 2015)

atunguyd said:


> Is it just! Of ate those chips coming of a dark blue? From my understanding that indicates SFM too fart for HSS does it not?


Just depends on a multitude of factors, I have gotten conflicting advice about chip colors. D2 for instance, the only way I have gotten it to come off clean without chatter and minimal tool wear it will be bright to dark blue. if it's ever a big concern a mist coolant system or even just compressed air will help reduce the heat a great deal.


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## FastPauly (Feb 17, 2015)

Have you done a "lift" test to check that the spindle bearings are within spec?


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## atunguyd (Feb 18, 2015)

atunguyd said:


> Is it just! Of ate those chips coming of a dark blue? From my understanding that indicates SFM too fart for HSS does it not?


Oh crap I really gotta proof read my posts. I really hate these on screen keyboards with predictive text. 

I was supposed to say :

Is it just me or are those chips coming off dark blue. From my understanding that indicates SFM too fast for HSS does it not.


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## mikey (Feb 18, 2015)

And here I was, thinking those guys down in Durban talk kind of funny, don't they?


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## customchris (Feb 18, 2015)

So blue is bad? I have seen them yellow and tan and blue .. What is the best to shoot for ? I turned some aluminum it did better but still had some chatter. I don't have the change gears so I can't adjust the feed rate. 

I was messing around today and the compond rest moves even with the gibs tight. its like it has slop in it.. I should have just got a new grizzly and dealt with the china parts at a latter time.


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## dracozny (Feb 18, 2015)

customchris said:


> So blue is bad? I have seen them yellow and tan and blue .. What is the best to shoot for ? I turned some aluminum it did better but still had some chatter. I don't have the change gears so I can't adjust the feed rate.
> 
> I was messing around today and the compond rest moves even with the gibs tight. its like it has slop in it.. I should have just got a new grizzly and dealt with the china parts at a latter time.


I have seen it argued ten ways from Sunday. most will agree that the color should be more straw like, I'm just saying not all materials will cut that way. Aluminum won't change color much from my experience. It may look a tad dull in comparison to the stock material due to some level of oxidation


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