Surface Mill this Fillet in 3 sections

[kgueorguiev]

I have to clamp this part down to the machine table, and because I plan to switch out the clamps from the center to the outer edges, I can't go around the entire perimeter of the part in one feature (I can do that afterwards in a separate setup, but ideally I want to machine all the top side features without taking the part off the machine table).

So what I need is to machine the fillet at the upper and lower sections (when the clamps are holding down the middle of the part), and then machine the middle section (when the clamps are holding down the upper and lower sections of the part). See screenshot. Some overlap past the line is preferred. 

[AJHanson]

why not put the holes in first and hold down thru the holes? 

[lee.hillman · Accepted solution]

Hi 

You have a couple of options that can give you what you require

1. Use boundaries to control the surface milling 
2. Use X section to create the fillet radius using a regular side feature.

I have attached a part with both methods .... Just around the top profile only

Let me know which you prefer and I'll explain how to do it

Regards

Lee Hillman 

[kgueorguiev]

Thank you for demonstrating multiple methods. I've never used X-Section so I'll definitely play with that at some point. In the Z-Level feature with the boundary, it looks like you checked "Limit toolpath to boundaries and stock" with 100% in the Boundary Curve dialog box in order to get it to stay within the line.

On a somewhat related note, notice how there is a larger stepdown in the toolpath when it starts at the top, and then smooths out as it cuts further down. How do I get the stepdown to be equal from the top of the toolpath to the bottom?

[lee.hillman]

Glad they worked ..... X-section has saved my skin many times .

The reason for the large stepover / stepdown is the strategy..... As you are using Z level ..This means that the first stepdown is exactly the same as the others, but because you are at the top of a radius ..... this forces a larger step over to maintain the stepdown distance.( hope that makes sense ).

Easiest way to avoid this is to use the Scallop setting on the milling tab.

Tick the checkbox and add a scallop height of around .001" or smaller. Don't be afraid to go down to .0001" if necessary

[lee.hillman]

BTW ...Don't forget to check the box for Scallop stepover , otherwise the scallop height setting will not be visible.

[bhorstTGM48]

I would like to add another tip that I always do in zlevel surface milling is I also tighten up the tolerance to get a better / smoother finish.