Adaptive Clearing Toolpath Issue

[chrisjh777]

Just curious about the toolpath generated in the attached Solidworks 2015 file and shown in the image below:

The CAM operation in the Solidworks file is named "Insert Seat Roughing"

The area being cleared is a 55° Rhomboid shape and the issue is, when the clearing path get to about the hallway point across the rhomboid, the path violates the maximum step over value (0.25mm) set in the parameters.  See Image.

The toolpath “gouges” inwards towards the opposite corner, with a resultant spike in the cutting width of cut.  A bit disconcerting on my small machine.  From then on, the cutting resumes normal operation.

I am still able to use this program to make this part but the question arises “is this a bug?”

[Rob_Lockwood]

Can't open it, i'm guessing you're on newer SW than I.. What is your tolerance value set at? If it's set to the default .004", what happens if you increase it to ~.0002"?

[chrisjh777]

Hi Rob,

I changed the tolerance to ±0.02mm (from the default ±0.1mm).

Behaviour is the same.

[scottmoyse]

It's because of the hole in the face you selected for Stock Contours... I also changed the model selections slightly.

Again the spikes in the image below are because of the stock contours, since the boundary includes an edge for the inner most hole...

[chrisjh777]

Hi Scott,

This makes sense.  I should have picked up on the hole.  I'll suppress the hole and regenerate the code.

Regards

Chris Humphris

[chrisjh777]

Hi Scott,

Many thanks for looking at this for me.  Much appreciated.

I had overlooked the hole in the bottom surface of the seat plane.  I created a copy of the part without the hole, regenerated the code and all is now how I expected the tool path to be. 

Having learned from this experience, the small spikes in the upper internal corner are no doubt caused by my corner relief hole.  This is of no concern however, because the incursions are into a pre-drilled void.

Once again, my regards and appreciation.

Chris Humphris

[Steinwerks]

With 2D Adaptive you should be able to use the stock without needing to suppress the hole: instead of selecting a face, select the outer contour or create a sketch that matches the stock contour. I find it much nicer than suppressing/unsuppressing features.

[scottmoyse]

N. Stein wrote:
With 2D Adaptive you should be able to use the stock without needing to suppress the hole: instead of selecting a face, select the outer contour or create a sketch that matches the stock contour. I find it much nicer than suppressing/unsuppressing features.

That's what I did... but the inner hole forms part of the face edge. So 2D Adaptive thinks there isn't any stock there and creates a spiky toolpath. It wouldn't happen with 3D Adaptive.

[Steinwerks]

scottmoyse wrote:

N. Stein wrote: With 2D Adaptive you should be able to use the stock without needing to suppress the hole: instead of selecting a face, select the outer contour or create a sketch that matches the stock contour. I find it much nicer than suppressing/unsuppressing features. That's what I did... but the inner hole forms part of the face edge. So 2D Adaptive thinks there isn't any stock there and creates a spiky toolpath. It wouldn't happen with 3D Adaptive.

I'm saying to create a stock without the hole at all. Shouldn't ever know it's there.

Edit: Scott you and I agree  😉

I've attached a screenshot of the Stock Contours selection that will hopefully clear this up to the OP: no extra model needed.

I'll add that there isn't any stock in the inner hole, it's already been drilled out.

OP: your other geometry selection is a little weird. I suggest selecting the two top faces as the "part" and setting the height via selection instead of "From Contour", and finally turning off "Machine Cavities" in the Geometry tab.

[scottmoyse]

N. Stein wrote:

scottmoyse wrote: N. Stein wrote: With 2D Adaptive you should be able to use the stock without needing to suppress the hole: instead of selecting a face, select the outer contour or create a sketch that matches the stock contour. I find it much nicer than suppressing/unsuppressing features. That's what I did... but the inner hole forms part of the face edge. So 2D Adaptive thinks there isn't any stock there and creates a spiky toolpath. It wouldn't happen with 3D Adaptive. Cool... did you notice that I'd attached the part with my toolpath in it further up this thread? I'm saying to create a stock without the hole at all. Shouldn't ever know it's there. Edit: Scott you and I agree  😉 I've attached a screenshot of the Stock Contours selection that will hopefully clear this up to the OP: no extra model needed. I'll add that there isn't any stock in the inner hole, it's already been drilled out. OP: your other geometry selection is a little weird. I suggest selecting the two top faces as the "part" and setting the height via selection instead of "From Contour", and finally turning off "Machine Cavities" in the Geometry tab.

[Steinwerks]

scottmoyse wrote:
Cool... did you notice that I'd attached the part with my toolpath in it further up this thread?

No, I hadn't noticed that you'd attached it.

[chrisjh777]

One thing I have noticed with HSMWorks/HSMXpress is, there is a myriad of ways to select heights for geometry as listed below:

Top
Bottom
Model Top
Model Bottom
Stock Top
Stock Bottom
Contour
Selection
Absolute (from Origin)

As far as I can tell, it shouldn't matter which starting point you begin with, as long as you have you wits about you, and get the maths right, you should end up the same result.

One thing I have found counter-intuitive is the means by which you select Open Pockets.  I find that I have to watch tutorial videos time and time again, and find that it just does not sink in. 

I now have a Post It note stuck to my wall instructing me:

FOR OPEN POCKETS:

"STOCK CONTOUR" means Stock to be Removed.

"MODEL" means "TOP OF CUT" (Not needed for Closed Pockets) (This is what I mean by counter-intuitive)

Select "MACHINE CAVITY" OFF

In this case, I did not follow my own instructions >: (but somehow managed to get a tool path which worked. 🙂

This is a classic case of many, many ways to skin a cat!!

I really should create and use templates for each of the common operations that I perform with my machines to give me hints as to how I did it previously.

[scottmoyse]

Model defines what you want to keep.
Stock Contour is what you want to remove
Turn Machine Cavities off if you want to machine outside of the edges selected to define the model (when the models edges selected form a closed contour)

Bear in mind, these selections aren't like this in the paid for 3D strategies... and to be honest are far more logical in Inventor HSM & Fusion 360.