Machining undercuts

[BillGEGHV]

Hey guys, Im working on programming some pretty complex casting molds. It is all surface machining with only the parting wall and a single surface that are flat all other surfaces are organic.  There are 2 small areas on one side of each mold 1/2 that has some undercutting in it. Its pretty minimal no more than .08-.09 I need to cut into the side wall to clean up the material and about .8 deep.  I bought a 4 Flute 3/8, 300-degree lollypop end mill. What are my best options for a tool path that can calculate these undercuts? Im on a 3-axis machine, no 4th axis and my goal is to resolve this undercut while machining in only 3 axes and not doing an angled setup. 

[a.laasW8M6T]

There are a few that will work

• 3D Contour
• Flow
• Flow(Preview) - turn on in preferences> preview features
• Ramp
• Blend - Also in preview features

I've had the best results with Flow(Preview), but it depends on the geometry you are trying to machine

[brad_francola]

Hi.  Steep and Shallow (in Steep Only Mode) will also project toolpaths onto under-cut geometry.  

[BillGEGHV]

Thanks much!

[BillGEGHV]

Thank you 

[BillGEGHV]

HUM, Im not seeing a preview option in preferences for flow or , could it be that it has already been implemented in the software?  What is the preview? Is it a "preview" before tool path is generated because I DO get a standard preview of the tool path "after" I click OK but that's just standard stuff. 

I did turn on the Enhanced flow strategy for use of programming step over distance instead of by the number of steps which just makes more sense.  Does this also enable the preview function? 

    

[a.laasW8M6T]

Its kinda confusing I suppose, in preferences its called enhanced Flow, but in the toolpath menu its called Flow(Preview) to distinguish it from the old Flow toolpath.

The is no Preview Function as such, it just means its not a fully released toolpath yet hence its in "Preview"

[BillGEGHV]

Gotcha thank you!

New version is much better with step over, why it would have been designated by a number of steps is beyond me? 

[BillGEGHV]

I've been working with the Flow option for programming these undercuts.  Have a new question on this after playing with it for a bit.  Is there any option in Fusion that will automatically figure out and calculate the tool path ONLY where there are undercut, and then maybe alow for an offset to bend the cut.  So far the flow command is giving me tool path everywhere and not discerning where the undercuts are. Im concerned to get lap lines across my surface since this tool path must be after my scallop finishing pass. 

[BillGEGHV]

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