5 and 4 axis Complex Surface Finish

[javi11]

Good morning peers,

 

I have been reading up on other topics lately on what scallop heights or step overs to use when youre trying to achieve a smooth / great surface finish on complex surfaces. At work I have to obtain surfaces finishes of 0.8 (or 32) or better on aluminum, but I tend to run into a problem when I am trying to accomplish that. Is there a formula to use in order to obtain a great surface finish like that because I always have to use different ball mills since every shape size varies. Or is there a rule of thumb perhaps to say, I should use the scallop height instead of the step over or vise versa?

 

Regards,

javier

[crazy^millman]

Really never used a formula. I have always just trusted my experience to help machine parts to the finish requirements. Have cut molds, prototypes, automotive, air-craft, and many other different parts have given me a good base of understanding about toolpaths. Rule of thumb I have always used I would rather cut something too nice or better than expected then risk cutting it to ugly. I have never had an issue making the part look good. Run time needs to always be considered, but the quality of the part also needs to be considered right there with it. I find myself always going counter culture in most places. I have always felt like my work is art and it should reflect something I want to put my name on. That is part of being a programmer I think it takes as much creativity and artistic abilities along with proven scientific formulas to machine and program parts.

[mkd]

I've never bothered with formulae either. although they do exist

32 finsish will with a ball...that getting down pretty fine. might be better off benching that.

I just had a part get inspected at a customers shop. VP was pretty unpressed with my 11 finish. Happy accident.

 

one consideration/trick with 4/5 axis is using very mild lead tilt with a square or bullmill. The effective cutter radius i quite huge compare to your average ball mill. so the stepover can be quite large.

 

[Guest]

There must be 50 surface finish calculators available all over the internet, a simple search should lead to many of them

 

Here's one that I use

 

https://www.dropbox.com/s/9qbtov4re5t1nco/scallop%20height.xls?dl=0