How do I remove / prevent tool chatter on pen?

[Novicewoodworker]

After I turned a pen from a wood blank, sanded it from 100 grit to 600 grit, and applied some Shellawax finish to it, I noticed tool chatter on it. I've considered sanding it more, but am afraid of completely ruining it due to it turned to its finished size. Also, I'm not sure why the chatter occurred. The chisel I used was a skew and I did not notice the chatter on the previous pen. I did notice, however, that there was a slight high pitched noise as I ran the chisel across the blank from time to time. Any advice is appreciated. Thank you.

 

[Haynie]

I am no expert but I seem to get chatter marks when my tool rest is not close enough to the material or Believe it or not, I am too tense. Sounds weird but when I relax I have fewer of these issues.

 

[Bowl Slinger]

What type of wood is it? What speed are you turning/sanding at? Its hard to believe that if you sanded from 100 to 600 you would have any tool marks in the blank. Can you post a picture of the issue? If I were in your shoes and the wood truly does have chatter marks in it then I would sand below the bushing diameter and then build it back up with CA.
A lot of chatter is also caused by a standard pen mandrel being too loose or tight. A mandrel saver will solve this issue. You may also want to try TBC and eliminate all chatter.

 

[Jim Burr]

Couple of things may help Scott. Sharpen those tools up, ride the bevel all the way through the cut. Slow your hand speed down...there is a relationship between lathe speed and hand speed, if your hands are moving to fast, you'll skip over areas of the blank.

 

[ed4copies]

Something is loose. (Hence the vibration)

Yes, it can be your toolrest is too far from the mandrel.

OR there is not enough pressure from the tailstock to keep the mandrel in the Morse Taper securely.

If you are using a "conventional" two blank long mandrel, you can have "center bow" developing as well. My only way of beating that is to use the "pro" adjustable mandrel.

But, since I have started turning one blank at a time on a very short mandrel, I have eliminated the problem you cite as well as eliminating "oval" pen ends.

 

[jttheclockman]

When a person usually posts a problem there are many factors left out in their posting. Now this becomes a guessing game. As mentioned you have a few very good guesses and I will add a few more. But before I do is this a special wood or a run of the mill wood that you have more of?? If so scrap it and start over. They sell replacement tubes for cheap.

You do not specify what method you are using to hold the blank, you do not mention if this is a 2 piece pen or a one piece, you do not mention what the wood is, and I can go on. But as I said a few good suggestions were made such as the toolrest. Need a sharp skew and you did not mention how you are presenting it to the wood which can make a difference. The mandrel you are using could be flexing. The madrel you are using requires a 60 degree live center which you may not be using and causeing slop in the end of the mandrel. You maybe cutting too far above center with your tool. I will say thjis if you used a skew and had to start sanding at 100 grit you are definetly not using the tool properly. If you need to sand at all start with 400 and be done with it. Apply your finish. Remember to sand with the grain after the lathe has stopped before applying finish.

Supply a few more details and then the guesses will get more exact.

 

[plano_harry]

To add to what John T said, after correcting any of the looseness issues, sharpening and tool handling - you need to stop the lathe and sand with the grain after rotary sanding on each grit of sandpaper change. Even if you had a really chattered blank, following that procedure from 100 to 600 should have removed virtually anything.

If all of the above replies and tips don't solve the problem. Provide more details and pics.

Harry

 

[low_48]

Rotate the skew a little. I usually have the edge contacting the blank at a 45 degree angle. Also ease up on the pressure of the tool on the wood. I sometimes have to concentrate on relaxing my hands. The cut is always better when relaxed.

 

[randyrls]

I did notice, however, that there was a slight high pitched noise as I ran the chisel across the blank from time to time. Any advice is appreciated. Thank you.

Scott; The high pitched whine is likely the source of the "chatter". The mandrel is vibrating and the blank picks up the vibration. Lighten up on your cut. Don't push as hard, and sharpen your skew. You might also want to try a different speed on the lathe.

I have this same problem with acrylics. The effect is like a "wavy" pattern in the blank.

 

[azamiryou]

I find it interesting that the "chatter" did not appear until after sanding and finishing (if I understand it right).

I've had unevenness appear during sanding with woods like palm that have very uneven hardness; soft parts sand away much faster than hard parts, and bits are left proud unless you keep sanding to a minimum and use a very light touch.

Starting with 100 grit is some pretty heavy-duty sanding. Is it possible the "chatter" you are seeing is softer wood sanded away leaving harder wood proud?

 

[Robert111]

What type of wood is it? What speed are you turning/sanding at? Its hard to believe that if you sanded from 100 to 600 you would have any tool marks in the blank. Can you post a picture of the issue? If I were in your shoes and the wood truly does have chatter marks in it then I would sand below the bushing diameter and then build it back up with CA.
A lot of chatter is also caused by a standard pen mandrel being too loose or tight. A mandrel saver will solve this issue. You may also want to try TBC and eliminate all chatter.

That's my take on it too. +1

 

[Novicewoodworker]

Your suggestions have been great! I slowed the lathe down and observed a slight wobble frm the mandrel. I have ordererd a new mandel and mandrel saver as well as adjusting the height of the tool rest. I believe that the problem will be corrected as soon as the new mandrel arrives. Again, thanks for the help. Next time I will try to be more specific on what is going on.

 

[low_48]

Your suggestions have been great! I slowed the lathe down and observed a slight wobble frm the mandrel. I have ordererd a new mandel and mandrel saver as well as adjusting the height of the tool rest. I believe that the problem will be corrected as soon as the new mandrel arrives. Again, thanks for the help. Next time I will try to be more specific on what is going on.

It's pretty easy to straighten a mandrel. With a bare mandrel, bring up the live center and just barely snug it up. Start up the lathe, place a pencil or sharpie on the tool rest at about the middle of the mandrel, and advance the pencil very slowly. As it touches the madrel, pull it back. The mark is the high spot. Tap the mark with a hammer. Repeat the whole process at a new spot. Maybe it bent back, maybe it didn't. You have to learn how hard to tap it. Once the mark gets about 3/4 or more around the mandrel, it's ready to use.

 

[Novicewoodworker]

I know this thread is old, however, I was able to get a picture taken of what I was talking about. This is a segmented part of a pen using pine and cedar. The 'chatter' is horizontal along the center of the piece. I know it's a little difficult to see, but it was the best I could do.

 

[chevyguy65]

That is hard to see.. im guessing you are talking about the horizontal band ? it looks like the wave from curly maple. In my experience i think the mandrel is bent slightly creating an out of round blank and the sanding itself created what you see now.

 

[jttheclockman]

I know this thread is old, however, I was able to get a picture taken of what I was talking about. This is a segmented part of a pen using pine and cedar. The 'chatter' is horizontal along the center of the piece. I know it's a little difficult to see, but it was the best I could do.

Well since it was an old thread, did you take in any of the advice that was given you and see if anything worked. From the photo I do not see what you are calling tool chatter. Tool chatter would be skips in the blank. High and low spots. If you did not take in any of the advice given then not much more we can say. There was alot mentioned and very good advice.

 

[seamus7227]

John, if you look above you will see that he did in fact take some or all of the advice given. You just have to read a little farther back than the most recent comment.

 

[thewishman]

Scott, when I had trouble with tool marks, I started sanding earlier. I would use the sandpaper to take down the last millimeter or two of the blank. That way, when I got to the correct size, the blank was perfectly smooth.

I asked for a mentor to show me the correct way to turn, there were three people who invited me into their shops. I learned more in those visits than a hundred videos or articles could have taught me. My technique improved with proper instruction and practice, and I have been able almost all of the sanding.

You may also want to start sanding with 180 or 220 grit rather than 100 - you will have fewer deep scratches to work out.

 

[jttheclockman]

Your suggestions have been great! I slowed the lathe down and observed a slight wobble frm the mandrel. I have ordererd a new mandel and mandrel saver as well as adjusting the height of the tool rest. I believe that the problem will be corrected as soon as the new mandrel arrives. Again, thanks for the help. Next time I will try to be more specific on what is going on.

OK Seamus points out that you tried things and from what I see this is what you tried. Did it work??? Is this photo before or after the trying of the new mandrel or the suggestions that were given. You should never have to sand to take care of poor technique, poorly sharpened tools, or poor equipment. Sanding is not solving the problem but covering it up and adding a step.

If you have a straight mandrel or the mandrel saver and you still have these results then you need to look at the presentation of your tool to the blank and the height of your toolrest. Also the sharpnest of your tools and the angle of the cutting edge. I suggest if there is a turning club join and learn first hand or see if you can find someone in your area to teach you. It is so hard to explain what to do by writing words. Seeing someone do it or watch you in your approach is worth it weight in gold when it comes to problems such as this.

That is all I have to offer. Maybe someone else can see the problem you are showing. My eyes are not what they once were.

 

[robutacion]

Hi peoples,

I was reading this thread from the very beginning and I was looking for any "guesses" that could take the problem to something that some new people to turning and to the various woods characteristics and grains visual effect, often gets caught as something unfamiliar and therefore a fault or a problem.

What I'm talking about is the curl/fiddleback/and other waving effects present in some woods, this is not a joke nor indicates any silliness from the new turner part, is simple something that people with little or no knowledge and or experience with "woods", can easily be taken for.

I remember at least twice I read in various forums I have been a member of through the years, of someone thinking that they pen barrels have "chatter" as they called it while the visual effect was what made them believe, there was a problem that they didn't understand.

What for some of us, is simple to understand and work out, can be not so easy for someone just starting using/wrking materials that they are not familiar with, that is more common that what some people may want to believe, but is a true fact.

I'm not claiming that, this is the case here but, those reading this thread that are in the "beginners category" can learn something from this and or become aware of its possibility...! :wink::biggrin:

Cheers
George

 

[low_48]

Are you still using a skew? That grain looks like it was scraped and not made with a shearing action. Are you using the skew like a scraper, or are you on top of the blank getting fine curls? Most wood will be almost burnished off the skew, and 100 grit would ruin the work. You should see a shine off a skew cut. A well made cut with a skew would allow you to start with 220. Watch a good video on skew cuts and get back to us.

 

[mikespenturningz]

Is it possible that the wood has some curl in it that you are mistaking for chatter?