Sharp Corner Cuts As Curve?

[Anonymous]

Hello all,

I am running into a weird issue.

I am cutting a triangle-custom shape, but the corners arent cutting sharp, they are cutting curved.

I am using a tapered mill tool to simulate the dims of our occilating knife. I am using the 2D contour to choose the path of the blade.

I attached a screenshot (CutLayer) and a picture of the cut part (Curve).

As you can see by "Cut Layer", the cavity is supposed to have two sharp corners, where I need our knife to rise, but instead it rolls around the corner, rounding it (like in the image Curve).

I can set an entry point on one of the corners, but then it still rounds the second because it's one continuous countor.

I want to find a way to cut this shape as individual contours, I guess. How would I achieve that?

Thanks!

[Anonymous]

Just to clarify, I am attaching another image. I need the tool to rise in the spots shown to avoid rolling around the corners. But I can't seem to select these as individual lines, only as one continous contour.

Thanks!

[Anonymous]

In order to not have the entire contour selected when you're picking your geometry you can hold the ALT key (at least on the PC) which will allow you to select individual lines.  I guess you would need to create multiple 2D Contour operations, but it should at least be a work around for you?

I'm curious, does the oscillating knife work as a drag knife?  Or is the control able to rotate it using another axis? 

Dave

[Anonymous]

Alt, Command, shift or Control don't seem to let me pick only part of the contour (I'm on mac).

I would be fine with creating multiple toolpaths (we kind of had to do the same thing in our old CAM program anyways).

The Oscillating knife does not work as a drag. If it did, the blade would snap. Our material is usually pretty thick foam (3" mostly) and the blade is 4" long with being about 0.25" wide and very thin. If it encounters a corner, it lifts automatically, turns, and plunges. On corners larger than 90 degress (probably around 100 degrees and more), it is just rolling around the corner, treating it as a curve.

In our old CAM program, we had an option called "Expolde Contour" which let us cut the contour as individual lines and curves, raising at each point. This allowed us to cut shapes like this with a tool raise at each turn (it was all individual toolpaths, and would have to be programmed seperately).

Thanks!

[Anonymous]

There should be another way to select only individual line segments, but it's not as easy as the Alt key - there must be some mac equivalent for that.

If you select the contour, then select it again a pop-up will appear with a Plus Sign and a red X and two contour selections above that.  If you select Open Contour instead of Closed Contour it should let you select part of the contour, then press the plus button to accept.  This is my first time playing with this option and it doesn't seem to always do what I want, but I'm sure I'm doing it wrong.  Hopefully it will work for you!

Dave

[Anonymous]

This workflow doesn't work on the cavity I need it to work on - it seems it is already seen as an "open contour". That is, "Open contour" is already selected when I edit it.

I can select specific sections of different cavities, but not this one. I have attached a screenshot showing it.

Is this a bug? Or is it an effect of the cavity shape?

Thanks!

[Anonymous]

Okay!

I got it to work but it is very strange how it behaves.

I have an attached a screencast. I hope someone can see this and tells me if it is a bug or not.

The workflow is:

Select contour

Edit contour

Choose "Closed Contour"

Choose OK

Edit contour again

Choose "Open Contour"

Deselect random selected lines (This is the part I think is a bug, one extra line is selected and I'm not sure why)

Accept

OK!

Usually, the line you select to "edit" is the only one selected in "Open contour" except in this shape, it ends up selecting two lines, no matter which line on the contour is selected. I think this may be a bug, or I'm misunderstanding something in my shape that is causing it to select two lines.

Also, I HAVE to chose "close contour", then accept, in order to select as open contour and get the behavior I desire.