2D pocket or 2D adaptive clearing

[jheinzmann]

Hi, 

I am trying to mill an inside ledge with a break in it and ran into problems with the 2D milling strategies. The problem appears to be reproducable with any geometry which is a frame with an inside ledge which has a break in it. When attempting to mill the ledge with either 2D pocket or 2D adaptive clearing, the tool paths do spare not only the break, but also mirror the break to the opposite side of the frame, leaving two breaks at opposing sides. Attached is an image. It appears any quickly whipped up frame/ledge geometry exhibits this problem. 

Am I doing something wrong or is this a bug? 

Many thanks, 

Jochen

[GPTech2444 · Accepted solution]

Hi, you need to click on the contour and then click the close box that come up and then click the inner edge.

I can do a screencast if you need it.

[jheinzmann]

Hi there, thanks looking at this! I was able to reproduce your method. 

Looks like this method depends on the tool diameter being smaller than the width of the ledge, and it looks like the machining is going to take a long time with this machining strategy. 

Playing around with this some more, I found that 3D pocket does pretty much what I was expecting the 2D pocket to do:

I must admit I am still a bit mystified by the behaviour of the 2D pocket strategy, and why it doesn't do (for a 2D ledge) the same as the 3D pocket. Having said that, I haven't entirely cottoned onto how selecting contours vs selecting faces and the open contour / closed contour feeds into the tool path strategies. If you happen to know of some reference material I'd appreciate if you could send me a link. 

Cheers,

Jochen

[GPTech2444]

Yeah I was also going to suggest to use the 3d adaptive, I did recently watch a youtube video (I can't find it now) on selecting contours like yours but I think it was for hsmworks in inventor and I think that fusion is still lacking some features that are available in hsmworks.
And the adaptive and pocket clearing strategies are intended to be roughing passes, in case you didn't already know that.

[jeff.walters · Accepted solution]

The main difference between 2D and 3D mill other than the operations is that 3D looks at the entire part while 2D only looks at the geometry you have selected.

In the case of 2D Adaptive and 2D pocketing if you have an open edge you need to tell the system that. Your geometry selection would be the outside of the pocket in this case. If this was an edge pocket than you would want to use an open boundary instead of a closed like we are doing here.

The second thing we need is to tell the system where the stock is we want to remove. That’s what Stock contours is for. For your stock selections you want both in outside and inside in this case so just pick the bottom face and you will get two yellow boundaries.

The system will now use the blue boundary as a containment or do not cross boundary, and since we don’t have a blue boundary on the inside it knows to cut past that edge. And the result is like this.

[GPTech2444]

Hi Jeff, I just tried this and I can't get it to work. I can't get the blue selection like you have in your first picture. When I select the inside corner of that pocket it will only select the face and won't extend across into the open area.
I watched a youtube recently and they were using the shift key to select the end and start of a chain and hsmworks was able to work how to cut around sections similar to this model, but they were using hsmworks so fusion maybe different in this area, IDK.

I just did a screencast.

http://autode.sk/1IOa1aZ

[jheinzmann]

Hi Jeff & GPT, 

I just tried this and it works, but only if you have an edge along the break of the ledge. When you open Jeff's model, you'll see his model has a different geometry to what we have been experimenting with, where there is no model edge between the frame body and the ledge break. To quickly make an edge I sliced the whole body along the plane of the ledge, and then the selection works as Jeff had outlined. 

The toolpath generates perfectly, exactly as one would expect. 

Jeff, thanks heaps, this is great help. If you are aware of some info material on this open and closed contour selection option that would be great. At the moment, I am unclear on when exactly this contect menu pops up, and what exactly the open/closed contour selection does. 

Thanks again.

Cheers, 

Jochen

[GPTech2444]

You can use the split body command there and it will do the same thing.
That's an extra step that you really shouldn't have to do.
Because you won't always be able to add in that split as it may affect other parts of your model.

[GPTech2444 · Accepted solution]

I found the youtube, I think it's Scott Moyse that did it.

Wish I found it earlier.

It works in fusion I just tried it, so no need to split bodies or anything like that.

Here's a screencast of what I did.

http://autode.sk/1K4uaGd

[jheinzmann]

Cool, this is great. The perfect cut. Thanks man!

[GPTech2444]

Cheers mate, we both learned something.

[Anonymous]

Interesting. The problem I have had many times is that the software will not allow me to select the regions I need to machine. Both the Geomety "Pocket Selections" and "Stock Contours" options are vague and confusing to say the least. It is almost as if the programmers understand a type of work flow, but it isn't shared with the end user. Making these two options work consistently is beyond challenging and mostly frustrating. I have found that they work fine on large features and it's hit or miss on small details like thin slots.

[kb9ydn]

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@Anonymous wrote:

Interesting. The problem I have had many times is that the software will not allow me to select the regions I need to machine. Both the Geomety "Pocket Selections" and "Stock Contours" options are vague and confusing to say the least. It is almost as if the programmers understand a type of work flow, but it isn't shared with the end user. Making these two options work consistently is beyond challenging and mostly frustrating. I have found that they work fine on large features and it's hit or miss on small details like thin slots.

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The geometry selection method is a bit unconventional, but once you understand it, it's pretty good.  Having to click the path again to bring up the open/closed option box is highly counterintuitive though.  I wish they would come up with a better method for that.

For small features you need to zoom in to be able to select the right edges and such, and it feels like sometimes you have to zoom in more than should be needed.  I think this is more of a Fusion thing in general and not just the CAM side.

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[Anonymous]

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@kb9ydn wrote:
 

The geometry selection method is a bit unconventional, but once you understand it, it's pretty good.  Having to click the path again to bring up the open/closed option box is highly counterintuitive though.  I wish they would come up with a better method for that.

For small features you need to zoom in to be able to select the right edges and such, and it feels like sometimes you have to zoom in more than should be needed.  I think this is more of a Fusion thing in general and not just the CAM side.

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What? You can click the path a second time and bring up an open/closed option box? My Fusion definitely does not offer this option. Maybe I am missing something!

[Steinwerks]

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@Anonymous wrote:

What? You can click the path a second time and bring up an open/closed option box? My Fusion definitely does not offer this option. Maybe I am missing something!

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It certainly does! You can also use Alt+left click to select individual chain segments.

[Anonymous]

Interesting. My system has so much lag that pressing Alt+left click results in that tiny dialog popping up a full 7 or 8 seconds later meaning I've never seen it!

Unfortunately, choosing either open or closed options had no affect on the tool path. It is still ignoring the pocket I clearly have selected.

thanks for the help!

[kb9ydn]

I think just about everyone gets caught by this at first.  If that box were to pop up immediately instead of requiring another click on the path it would be SO much easier to figure out.

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[kb9ydn]

Can you at least post a screenshot showing the selected geometry?  If this is an imported solid it is possible there is something wrong with it that's mucking up boundary selections. I just ran into this the other day.

And unless you're on a really slow computer it shouldn't have that much lag.

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[Anonymous]

I did post screen shots of everything in a different post.

[kb9ydn]

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@Anonymous wrote:

I did post screen shots of everything in a different post.

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Ahh, yeah just noticed that.

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