LouLeggett
Member
What is the cause of tool chatter? Near the headstock, all is smooth and no chatter. Turning the lower barrel near the tail stock, chatter starts and nothing seems to dampen the effect.
Tool chatter
- Thread starter LouLeggett
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Most will probably say dull tools and mandrel flexion.
With the dull tools causing the mandrel to flex more than if you are using sharp tools. There is a lot of support at the head stock so the mandrel doesn't flex as much in that area.
With the dull tools causing the mandrel to flex more than if you are using sharp tools. There is a lot of support at the head stock so the mandrel doesn't flex as much in that area.
wdcav1952
Activities Manager Emeritus
Lou,
That sounds like you might have a slightly bent mandrel. Check your mandrel for a bend, make sure your retaining nut at the end of the mandrel is not too tight. One method I use is to have the mandrel turning with no blanks on it. Let a pencil rest lightly on the mandrel and move it down the mandrel. If the pencil bounces, the mandrel is likely bent. Also, hard though it may be to believe, having the nut too tight or too much pressure on the mandrel with the tailstock can flex the mandrel, causing your problem.
Some beat the problem by only turning one end of the pen at a time, keeping all turning near the headstock.
FWIW,
That sounds like you might have a slightly bent mandrel. Check your mandrel for a bend, make sure your retaining nut at the end of the mandrel is not too tight. One method I use is to have the mandrel turning with no blanks on it. Let a pencil rest lightly on the mandrel and move it down the mandrel. If the pencil bounces, the mandrel is likely bent. Also, hard though it may be to believe, having the nut too tight or too much pressure on the mandrel with the tailstock can flex the mandrel, causing your problem.
Some beat the problem by only turning one end of the pen at a time, keeping all turning near the headstock.
FWIW,
Tea Clipper
Member
It could also be that the live center you are using is not 60 deg. For example, if you are using the stock center with a Jet mini, that is 30 deg and would wobble on the mandrel shaft causing chatter or out-of-round issues.
GBusardo
Member
Does this happen on more than one blank? Its possible that the grain of the wood turns and at the very end? Then at that part of the blank you would have a cross cut blank that is much tougher to turn. Just a thought.
fstepanski
Member
Couple questions, thoughts...
Is the tool rest the same distance from your work at the headstock and tail stock?
Is everything snug i.e. tail stock locked?
With the lathe off, can you wiggle the lower barrel?
Are your bushings snug on the shaft and pen tube along the lower barrel?
Please let us know what you've isolated the problem to be..
Is the tool rest the same distance from your work at the headstock and tail stock?
Is everything snug i.e. tail stock locked?
With the lathe off, can you wiggle the lower barrel?
Are your bushings snug on the shaft and pen tube along the lower barrel?
Please let us know what you've isolated the problem to be..
stevers
Member
I have this problem quite a bit too. Always near the middle and end of the second barrel. Seems to be present on wood, resin and any combination of the aforementioned. (my big word for the day[
]) I have thought of turning one at a time. Lee (firefighterEMT) has a possible new solution. He is sending me some new style bushing to try. We'll see how that works out.
My mandrel is pretty straight. It occurs with most types of bushings. My nut isn't too tight. So I lean toward the idea of flexion of the shaft.
I'll be interested to see further data on this one. I really hate that chatter near the end.
Also , I have a little luck when I switch to the Skew.
]) I have thought of turning one at a time. Lee (firefighterEMT) has a possible new solution. He is sending me some new style bushing to try. We'll see how that works out. My mandrel is pretty straight. It occurs with most types of bushings. My nut isn't too tight. So I lean toward the idea of flexion of the shaft.
I'll be interested to see further data on this one. I really hate that chatter near the end.
Also , I have a little luck when I switch to the Skew.
cdcarter
Member
Had a little of that last weekend with my "B" mandrel, and am almost certain it was a matter of the nut being too tight.
cdcarter
Member
Had a little of that last weekend with my "B" mandrel, and am almost certain it was a matter of the nut being too tight.
LouLeggett
Member
Yep...turn out to be nut too tight!
fstepanski
Member
Better than a loose nut []
]
Rifleman1776
Member
All of the above plus just a charateristic of using a long, thin rod as the mandre. They have some flex and, depending on the blank, your tools and speed of lathe, chatter is (almost) inevitable. I use an adjustable mandrel or the no-mandrel method of turning to eliminate chatter and getting oval pens.
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