10:1 ratio long tools
10:1 ratio long tools
(OP)
We are having a bit of trouble kellering deep pocket walls with tools that have 10:1 ratio length to diameter. Does anyone know what tool holders are more rigid. Deflection is happening even at slow feedrates. Spindle will go 24000 rpm max. We tried a .500 endmill .120 radius 10:1 ratio reduced tapered shank and even at 20 ipm we had alot of deflection. Any help we be greatly appreciated





RE: 10:1 ratio long tools
As for tool holders, if you are running at 24K rpm I'm guessing you're using HSK style holders. Additionally the tool must be balanced so that the rotational vibration does not combine with the vibration induced by the cutting process.
Also the speed, feed and DoC (depth of cut) must be examinied. This is critical in controling your problem. Talk with tool suppliers since the cutting geometry of the tool will greatly define the tool forces that drive vibration from a very large L/D ratio tool.
RE: 10:1 ratio long tools
CODE
http://airy.pec.ncsu.edu/PEC/research/projects/small_mill/aspe1999_abstract.pdf
http://airy.pec.ncsu.edu/PEC/research/projects/force_feedback_tool/index.html
http://www.moldmakingtechnology.com/articles/030401.html
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RE: 10:1 ratio long tools
Combining this with a shrink-fit toolholder for a stiff assembly that has good balance and run-out and you might get there (or at least near your 10:1 ratio needed).
RE: 10:1 ratio long tools
http://www.mmsonline.com/articles/1196scan1.html
They have made special purpose long rotating tools with built-in vibration dampers. They are touchy to set up. Same concept has been used for a long time on non-rotating boring bars.
RE: 10:1 ratio long tools
-try smaller radii and increase feedrates.
-what shape is your spindle in?
-locating tapers ok?
-try a 3 flute cutter.
-buy a 5 axis mill
RE: 10:1 ratio long tools
They have a toolholder system which name is Tribos. Once a time I searched the min tool holder diameter for the same shank in a group consist of shrink, tribos, weldon, hydrolic types. The result was tribos.
Jck26 is definitely right. Prepare your tool with min length. If you have an extention, cut its length that you don't need. But please consider the min shank length requirement when you decide to cut it. Also reducing the cutting speed can be a solution for the long tools. Max DOC must be 0.3xDiameter but you can reduce it according to your conditions.
RE: 10:1 ratio long tools
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com