Carbide 3d smooth finish cut...issues

how do you get the smoothest finish in 3d projects?
I get a decent finished product but is there a way to minimize the ball mill grooves?
i am running my projects down to the smallest bits, i see other 3d projects online that look really smooth?
still in the learning phases of my shapeoko pro

any guidance is appreciated

My general guideline is to scale your finishing stepover to the ballnose endmill you’re using.
10% x Diameter or greater = rough finish.
5-9% x Diameter = Decent compromise of speed and quality
<5% x Diameter = Very good quality

This means that if for example you use a 1/32" endmill, you need to take super tiny stepovers that are going to take a very long time. If you want to save time, you should use the largest diameter ball endmill you can get away with.


You want to use the largest ball mill you can & still get the detail you want.
Using Winston’s formula, or anyone’s for that matter, 5% of 1/2" is a lot bigger than 5% of 1/8"
and will result in fewer stepovers & a shorter toolpath. But won’t be able to get in the tight corners.
The ideal solution if you have large areas of lower detail is to finish them with a larger tool, then just use the smaller tool to get in the tighter corners. But you’d need a more robust CAM software than CC to do that.

There are many scallop height calculators out there. Milling Step-over Distance Calculator for example. For that really fine finish, you want less than a 0.001" scallop height.

Somebody needs to invent a dynamically adaptable ball mill which changes shape as the RPM increases…small ballpoint tip at lower RPM range to larger/donut shape ball end at high RPM’s.

Then I’d like to see the algorithm & math needed to calculate how to run that over a complex surface topology! Hahahaha!

Thank you
so it is all about the step over.
smaller the better.

also I’ve learned to not be afraid to use a flat 2mm bit for 3D designs if the design has a lot of “flat” areas… still needs a very small stepover, but for some designs I’ve found this to work better than a ball nose bit…
likewise for more “stringy” woods, the normal cutter ends up doing better since ball nose geometry often has issues with the strings


Curious if CC 3D finish path accurately drives a flat end cutter?? I’ll have to give it a try & simulate it to see if it violates the model. I imagine in a lot of wood decorative projects it doesn’t matter.

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