Chattering

[Nicky S]

Why do my tools chatter when I trim ?Not the effect I want No matter what position I hold tool I seem to get that effect  Happens very often Thank you Nicky 

[Hulk]

Is your work a bit on the dry side for trimming? Seems to me there's a tradeoff between firm enough such that the work doesn't get deformed and soft enough so the chips curl away smoothly. I'm leaning toward the former. Another factor may be sand/grog, which catch on the tool's edge. 

Any road, the trimmed surface can be burnished with th' flexible metal rib o'death (see Tim See), and if that doesn't smooth the micro chatters, try dampening with a sponge first, and give it a minute to penetrate a bit.

I like on purpose chattering, where the flexibility of the tool is a factor. For not chattering, gripping close to the cutting edge and solid anchor - two hands, and/or braced against splash pan, leg - seems to make a difference. Wheel speed is a factor as well; for not chattering, does slowing down help?

[liambesaw]

One hand on the handle of your tool, the other hand bracing the bowl and also with fingers on the tool will help a lot.  So will sharpening your tool.  Slow it down a bit like hulk said as well.

[neilestrick]

Hold the tool tighter, and experiment with  changing the angle of the tool against the pot. More wheel speed can help, too.

[Nicky S]

 

Thank you @neilestrick @Hulk @liambesaw

 Much appreciated Will try ALL techniques 

[GEP]

When I experience chattering, it’s because the pot is too soft for trimming. The best solution is to set it aside and wait for it to become firmer. If I don’t have time to wait, my solution is a two-fisted death grip on my trimming tool, with both elbows braced somewhere. I concentrate on not pressing the tool against the pot, instead holding the tool still and independent of the pot. I hold the tool where it will shave off the highest points of the chattered surface, and slowly work down to the lowest points. At that point the pot will be smooth again, and I can relax and resume trimming normally. If the chattering returns, I go back to the two-fisted death grip. 

[liambesaw]

Sometimes it helps to turn your trim tool diagonal to the axis instead of perpendicular when removing stubborn chatter marks.  Instead of the top picture do the bottom one to remove them.  At least that's how I do.

[Mark C.]

When I trim I feel the need for speed-

for me chattering is clay is to soft and or to slow wheel speed

also a tool with less surface area will help-I have not used a pear corer for decades  except for the handle is the perfect size to measure a candle holder hole size.

There has been. a lot written on this already as most want to chatter

use the search function from main page to find topics on this.

[curt]

I think dull tools can also contribute to chattering.  Make sure your tools are sharp.

[Babs]

Like GEPs description.

Where are your hands in relation to your body...have you got them fixed or is it all getting away from you....

Grip of death sounds ok..

[liambesaw]

Grip of death sounds painful haha.  I would rather brace the trimming tool with both hands.  I do an initial bulk trim with my Dolan pear and then finish off with a hacksaw style tool.  If I start with the hacksaw style I get more chatters even while bracing the entire blade with both hands.  I think with just more time and experience you kinda figure out how to hold the tools to get the best out of them.  I tried to draw a picture but it I don't think it says what I feel like it should.  Gotta get that sharp edge right in there and spread the cutting surface horizontally and then swing it down into the chatters and it just blasts them all away.  More of a feely thing than an explainy thing.

[Babs]

I fix the elbows bit of left hand on pot and rest on tool and  tool hand about 4 or 5 o clock unless trying to chatter then tool hand is further from body  like the tool is trying to catch the pot before it spins around the corner and so the tool gets bouncy....

Perfect picture????

[liambesaw]

Very good!

[Nicky S]

12 hours ago, liambesaw said:

Sometimes it helps to turn your trim tool diagonal to the axis instead of perpendicular when removing stubborn chatter marks.  Instead of the top picture do the bottom one to remove them.  At least that's how I do.

Multi talented .... great graphics :-)

[GEP]

9 hours ago, Babs said:

Like GEPs description.

Where are your hands in relation to your body...have you got them fixed or is it all getting away from you....

Grip of death sounds ok..

The location of my hands in relation to my body depends on the width and height of the pot, but I keep them as close to me as possible. And make sure that my elbows/forearms are braced. I also lean forward a lot so the weight of my back helps to steady the tool. Here's a photo of the chatter-killing death grip:

[Pres]

No one here has mentioned the sharpness of the tool. I use dull tools when trimming wetter clay, and sharper tools when trimming leather hard  clay. Think of it the same as using a wire end tool to carve into wet clay for sculpture vs a ribbon end tool for finer finishing when the work is drier.

 

best,

Pres

[neilestrick]

I disagree that dull tools chatter more. My students have much more trouble with chattering when they're using new, sharp tools.

[Nicky S]

4 hours ago, neilestrick said:

I disagree that dull tools chatter more. My students have much more trouble with chattering when they're using new, sharp tools.

Seeings I’m the blondie here will let you know :-)

[Babs]

8 hours ago, GEP said:

The location of my hands in relation to my body depends on the width and height of the pot, but I keep them as close to me as possible. And make sure that my elbows/forearms are braced. I also lean forward a lot so the weight of my back helps to steady the tool. Here's a photo of the chatter-killing death grip:

 

NOW you have me scared!

My questions were really aimed at the original poster because I thought maybe the prob.is " sloppy" arms and body.....

In my post above I meant to write the fingers of  my left hand tests on top of pot and is braced into one with my right hand which holds the tool.

How did you take that selfie????

[GEP]

 Aha, I misunderstood your comment and thought that question was for me.

1 hour ago, Babs said:

How did you take that selfie????

 I’m pretty sure this question is for me, and the answer is tripod and self-timer. Real camera, not smart phone. These days I’m also shooting a lot of videos so the camera and tripod are always around. 

[curt]

11 hours ago, Pres said:

No one here has mentioned the sharpness of the tool. I use dull tools when trimming wetter clay, and sharper tools when trimming leather hard  clay. Think of it the same as using a wire end tool to carve into wet clay for sculpture vs a ribbon end tool for finer finishing when the work is drier.

 

best,

Pres

Pres I made exactly this point about 7 posts up from yours .

 Let me add that I have extensive personal experience with dull trimming tools.  And I inevitably get even more experience periodically when I procrastinate on sharpening those tools.  

Every so often, when I have completely run out of  sharp trimming tools in my workshop, I have to stop whatever else I am doing, get out the bench grinder and spend a morning sharpening them all up.  Let it be said that I own few (if any!) high quality trimming tools, mine are almost exclusively Chinese cheapies which I purchased when I didn’t know any better, inherited from others or been gifted, so I don’t mind taking off plenty off metal with the bench grinder (which makes up for a lack of finesse and precision with sheer brutal grinding power).  I can tell you that sharpening them up this way DOES make a huge difference, so if you have access to a bench grinder and a healthy supply of cheap tools give it a try.  Mind you, I don’t think I would do this with high quality tools, which I would hand sharpen much more carefully.

A dull grinding tool, a pot which is too stiff (a stiff leather hard or beyond), and wheel speed which is a bit too fast is the perfect way to propagate chattering in my experience.  My take is that this is because the dull tool just bounces over the clay surface rather than cut in.   As you try to press harder to get the dull tool to dig in, you can risk damaging your pot if it is delicate, and the chattering often just seems to get worse!  Sharp tool is often the solution.

[Pres]

curt, missed your earlier reply. . duh. However, I have found that the sharper tools usually chatter more if not held well. I have done a lot of sharpening over the years, and use files where needed, especially on some of the tight curved trimming tools I have. I also like a mounted belt sander with a good worn medium sanding belt to finish on the flats and outside curves of tools. 

 

best,

Pres

[Rex Johnson]

Funny, I find chattering sometimes when the pot is getting too FIRM...whatever, most important is that your tool is sharp and clean. As others mentioned a firm and steady hold is important.

Try holding the tool with the thumb at  two forefingers and steadying your hand by resting the other two fingers n the pot as it turns.

"Cupping" the pot with your other hand will help give you a sense of accuracy and stability. You can also use fingers on both hands to steady/cup, while resting the non-tool thumb on the trimming hand.