sphere mill

[elraiis]

hi guys..

a quick question and any input is greatly appreciated as usual..

am making a mold.. using a sphere or (ball mill). does anyone know what ideal % of tool diameter should i overlap to have a neat finish. i know the smaller the better... but i don't want the part to take forever inside the machine as well.. i am using a 1/8sphr mill and my overlap is .0012.. the finish is beautiful.. but i was wondering how much can i increase the overlap without starting to have (bumpy) surface... is there a certain percentage of the tool dia? any clue?

thx guys..

[kujo763]

It really depends on the average angle of the surfaces you are cutting, mostly flat or mostly verticle? That is realy tight. .003 to .004 for most stuff, what type of finish does the polisher expect?

 

Erik

[Mark H]

I just put a scallop height excel spreadsheet file on CAD's FTP under "Apps_files" called scallop height.xls

 

Also if you do a scallop toolpath check out the finish scallop parameters tab and select the max stepover button. Here you will see the scallop height versus step over - for both at a flat bottom cut and at 45 degrees.

[mchin-pilot]

Draw the cusp height and feel the bumps.

 

I mean draw two circles( the dia being the dia of cutter)

Make them apart by the stepover u intend.

Check what is the resultant bumb height.

 

It is a geometrical way to judge it. Simple!

[elraiis]

hi

am using parallel surface finish and rough... the part is very wavy, no flats... i have no clue how to describe it... just wavy and not a consistent wave either... sorry donno how to explain it better. the part is practically 1 x 7.5 long by 3 wide.. its taking around 3 hours in the machine.. i was just trying to improve the timing.. thanks for the help guys.. i guess i have to experiment..

peace

[elraiis]

mchin pilot.. thx i'll try that as well.. sounds simple and can give me a rough idea.. thx

[Mark H]

The spread sheet I put up on the FTP site gives you the cusp height (scallop height). All you need to do is type in the ballmill diameter and the step over.

[elraiis]

ok thanks alot.. i'll try to get to the ftp site.. never used that before.. i appreciate it man.. thanks alot.