View Full Version : Need Help! trying to get a good 3d finish


project5k
03-05-2009, 04:02 PM
I've read all over here and i'm still not understanding how to do what i want to do...

First, some basics, V22 pro with art.

just as an example, lets say i have a hemisphere depression into a flat topped block,

now i can do the basics of getting that machined, but my questions start when i want to try and get a better finish to my parts through machining it, rather than hand sanding and polishing... as it is now, all i have is endmills, so i'm working on getting some ball mills,

but what function in the software should i use to get that nice smooth finish like i see on every tv show, so that really all i have to do is a little polishing?

when i bought the software i was told somethng about equidistant somethine or another.... but i dont understand how to use it or if that will even give me the results that i want...

Allen123
03-05-2009, 04:24 PM
Yes run a ball mill!

When you step the tool over there are ridges left. By reducing the size of the ridges you get a smoother finish.

You do this by changing the step over for the tool.

The smaller the step over the small the ridges.


The better finish you want the smaller the tool step over will be.

project5k
03-05-2009, 04:41 PM
ahh ok, i kinda thought that, but wasnt sure, so lots and lots of small passes then.. cool, now what about the equidistant stuff in bobcad? what would i use that for?

Allen123
03-05-2009, 05:04 PM
Same thing, but the equi D. tool path does an absolute step over to the surface where the slice tool paths are incremental.

This about it this way when you are cutting a slanted surfaces using a planner tool path.

You give it a step over amount, what ever it is, the software steps over that amount but the slanted surface will have different ridges or scallops.

If you use the equi D. because it's an abs step over you will get the same scallops over the slanted surface.

http://i564.photobucket.com/albums/ss86/damjuice/3d1.jpg



See how the planner tool path had the different ridges or scallops and the equi D below has the same ridges or scallops through out.

http://i564.photobucket.com/albums/ss86/damjuice/3d2.jpg


Keep in mind that it's just not about the step over it's also about tools and speeds and feeds.

project5k
03-06-2009, 09:15 AM
ahh, ok, i see now, that would make a difference in the quality of the finish of my parts...

ok, so i just ordered a couple ball mills in the sizes i'm most likely to use... I just went ahead and got them from enco, i've allways had good luck with them, we'll see how this turns out.. i got:
321-6605
321-6610
321-6615
and a couple other regular endmills that i needed...