Milling interior corners

[Anonymous]

Lets say I am milling a square hole into a piece of material so that a square rod (with sharp corners) can be later inserted, is there a way to have 2D Contour automatically mill away the interior corner radii even if it means to cut into the material? I just don't want to have to model a interior corner condition at every corner.

[Steinwerks · Accepted solution]

Nope. However you could just create a "hole" at every corner intersection and drill them out first.

[ProteumMachining]

You could either select each corner as a point to drill through with your endmill as stated above or there was a custom API to add dogbone cutouts to flat pack items.

https://www.youtube.com/watch?v=ZCcD4MYGbzc

[Steinwerks]

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@ProteumMachining wrote:

You could either select each corner as a point to drill through with your endmill as stated above or there was a custom API to add dogbone cutouts to flat pack items.

https://www.youtube.com/watch?v=ZCcD4MYGbzc

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That's a pretty cool addon. I would add that it certainly has many applications aside from woodworking, too. I used to create tangent arcs slightly bigger than my nominal cutter in Mastercam when I needed an internal corner clearance for a punch or stripper plate, and those were more on the order of 3/4" diameter. I'll have to pick that up and see how it works.

Thanks for the heads up!

[Josh3GG88]

is there any prospect that this feature will be coming in the future?

[scottmoyse]

There's a trick with the 2D Contour rest material setting to trick a tool to drive into the square corner to create the relief you need. I would need to mess around with it to figure it out again though. 

[seth.madore]

🤔

I'm not aware of this trick...curious now, for sure

[brad.francola · Accepted solution]

@scottmoyse here is the example from our other thread.  Duplicate the 2D contour toolpath, activate rest machining (with a tool diameter equal to the tool used to cut the 2D contour) and then use negative stock to leave to make the undercuts.

[Josh3GG88]

this is a good trick and could be used for all corner cleanouts. Also very simple to apply.  However the CNC operators are complaining it is too time consuming, adding additional 10 minutes to a sheet for this option. is any way this option could be combined with the perimeter contouring?

[seth.madore]

@Josh3GG88 you could model those features into the part and use a smaller tool for it. I also seem to remember a "dog-bone" addin that would automatically add them for you.

The other option is to use a smaller tool and "drill" the corners out

[jscott6SWZG]

so seems like some quick bores solves the issue