Tapered Hole in Stock

[info99H4D]

Hi all,

Is there a way to rough out a tapered hole in the top of a piece of stock?  I'll explain what I'm wanting to do:

I've already machined this block and in this op I'm removing the excess material.  The bore in the centre is already roughed out but what's happening is that the material around that hole is breaking off and chipping my cutters.  My idea is to bore a tapered hole on the top of the stock so that its kinder on the tool.

See video below for a Titan's of CNC video explaining the theory and application in Mastercam.  I can't work out how to do this in Fusion.

Brilliant Technique that All Machinists can use to Prevent Breaking End Mills

[programming2C78B]

confine your boundary to inside the stock contour and  it'll start by ramping the center.

[info99H4D]

But then I'll get the problem as the cutter gets to the edge of the part / stock.  

The issue is that there will be either an island (outside to inside) or a wall that will eventually become thin enough that the cutter will tear it off which often leads to tool breakage.    This video from Titans of CNC explains it better than I can:

Brilliant Technique that All Machinists can use to Prevent Breaking End Mills

[DarthBane55]

I've watched the video.  You can easily do this in Fusion, just model yourself a block with a tapered hole in it on top of your part, and use the Bore operation.  It will mill the tapered hole.

An alternative I often do when I have this problem, is that I model the opposite... I model a post in the middle of the part, which is big enough that it will not snap (1/4" or depends on the height of it too).  So when the adaptive path is finished, I have a boss in the middle, which I just remove by facing with small cuts (boss diameter is smaller than my tool, so 1 pass removes all material, but I take small Z passes to face it all off).  This never breaks a tool and it does not add much cycle time at all.

[Linus_Follinger]

Create a 3d body thats tapered where you want the roughed taperd hole.
and use the the "model" option in 3D adaptive toolpath to select the taperd 3d body.

i can make a quick file as an example when i et home from work if you want to see how i replicated that technique fron titans of cnc.

[seth.madore]

Just use a sketch with 2x 2D Adaptive toolpaths, the second using negative radial stock to leave?

 

[info99H4D]

Thanks, or a bore operation would likely do the trick as well.

[info99H4D]

Thanks, it's a bit clunky but would do the job.  I'll give it a go.

[info99H4D]

That wouldn't leave a tapered bore though would it?

[seth.madore]

2D/3D Adaptive have a Helix Taper option:

 

[info99H4D]

Ah OK,

I think I had mis understood your workflow.  Makes more sense now and would achieve what I'm hoping.

[DarthBane55]

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@info99H4D wrote:

Thanks, or a bore operation would likely do the trick as well.

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Literally in the first sentence of my answer 😂