Tips Of Lathe Tool Bits Rolling Up.

BarnyardEngineering said:
By "rolled up" I mean the sharp tip of the bit is bent upwards.
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Paul in OKC said:
I am still gonna bet it is material build up.
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I think Paul has it. Often aluminum will 'build up' on the tip of the cutting tool instead of shearing away. Remove the build up by pushing (with a loose piece of aluminum) against the buildup, parallel the top surface of the tool, until the build up pops off.
Avoid buildup by using a lubricant. Some suggest WD40, which is a water displacement material, I use A-9 cutting fluid, just a drop or two on the work. High cutting speed will encourage buildup of both metal and heat. Keep the work and the tool bit cool by using lower speeds.
 
T Bredehoft said:
I think Paul has it. Often aluminum will 'build up' on the tip of the cutting tool instead of shearing away. Remove the build up by pushing (with a loose piece of aluminum) against the buildup, parallel the top surface of the tool, until the build up pops off.
Avoid buildup by using a lubricant. Some suggest WD40, which is a water displacement material, I use A-9 cutting fluid, just a drop or two on the work. High cutting speed will encourage buildup of both metal and heat. Keep the work and the tool bit cool by using lower speeds.
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What does the finish on the workpiece look like?
 
No, the tip of the tool is actually bent upwards. There's no material to pop off, and when I try to force it the bent-up tip breaks off.
 
Don't say if you wee just facing, or turning as well. If just facing, I would say your tools are below center a hair too much. When you face past center your tool tip is on the 'up'side of the rotation of the part, which can crack the tip a bit and force it up.
 
Agree post a pic of your setup, and with the tool up against the material. also a pic or two of what you said is a ruined tool may help. What I was thinking of is if you were working to on the metal to far out from the chuck and it is flexing up to ride over the tool. Often those HF tools are not really sharp, thus you need a diamond stone or something so you can sharpen them. Prior to having problems what do your chips look like.
 
Assuming you are using a chuck to hold the work, how much material to you have sticking out past the jaws of the chuck? What size is the HF tooling that you are using? How much of the tooling do you have sticking out beyond the tool holder? Generally the less tooling and work you have sticking out the better. Using the largest tooling you can get away with also helps.
 
Sorry, I have no clue what you are talking about, can't offer any suggestions if the problem is not well understood. I'd be interested just to see what the heck a rolled up tool bit is.
 
It sounds like the cutting edge of the lathe tool is too "thin". Did you grind these tool bits?
Mikey on the Machinists Blog has a nice write up on grinding lathe tools bits.
Also, using good quality lathe tools may help; RexAAA or Cleveland MoMax.
 
Just about everybody including myself tempted buying HF for cheap. And all of those I had to tweek.
So I don't use those . I suggest grinding your own HSS blank with a end radius. I just find HF 's
seem not to have relief and rub and have square shanks so other than grinding your stuck with it.
We don't have diamond wheels, so a die grinder & cut off wheel is used (need steady hands for that)
Good thing about HSS you dress up as needed over and over.
Harbor Freight stuff is dull out of the box.
 
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