Machsupport Forum
G-Code, CAD, and CAM => G-Code, CAD, and CAM discussions => Topic started by: pedroesteves.biosurfit on December 21, 2009, 08:56:12 AM
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Good afternoon,i have a question.
I´m micromachining a a PCB board(copper material) ,i´m using a 0.254mm mill with 15000 rpm,and a 81mm/min feedrate,and taking 0.100mm per passage,however,the mill brake after a little while.
i´m consulting inumerus books off cnc machining ,and the values i use,aren´t too far diferent from the values from the books.
Does anybody have a sugestion?
Thanks
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Even when i put an higher rotacion(30000 rpm),and lower feedrate(31 mm/mm) and deepht of cute (0.100mm), the mill(0,254mm) still brake.
I´m using the formulas and data from Gurhring and sandvik catologs to get this values.
N = (1000x Vc) / p x 0.254 adicional information Pi= 3,14 , Vc(for copper)= 27
F= N x Fz x Z , adicional information Fz=0,0005 , Z =2
I will apreciate any kind of help.
Thanks
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Are you using HSS or Carbide mills, PCB board is very abrasive and needs very hard cutting tools.
Graham
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I´m using a carbide Mill from PMT.
I´m using a two flute micro/miniature endmills are designed for the machining of small electronic components and highly abrasive materials.
that information is in the personal page of PMT,the brand of my miils.
I think taking all the right steps.
Proper mill,proper machining condition,good fixation off the mill and the PCB board ,good refrigeration...................Missing something?
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How much run-out in your spindle? .. Even the high quality micro mills get beat up pretty badly by spindle run-out.
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Hi Pedro
Can I ask what micromachining spindle are you using?
I was going to buy a Nakanishi, but the lead time is 4 months and I need something faster.
Best Regards
Pablo
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Too high a feedrate.