In CAM can not properly select pocket

[Anonymous]

I have fought with this for hours but have given up and come to you for help. The attached model is a solidworks STEP download. the notched out areas on the left and right are identical but I forgot to fillet the one on the right so I added it in Fusion. When i go to pocket mill the area the right side selects correctly but the left side will not do the same no matter what I try. I am suspicious there is something in the different model features but I am new to this and could just be missing something. The red arrows constantly show up on the left but not on the right which I don't understand.

BIG thanks!

Tom

[LibertyMachine]

Honestly, the one that "works" surprises me, as it's open on both ends, I'd expect it to behave differently.

It's hard to tell when two "identical" features behave in different manners. Common sense would suggest the both fail or succeed. Not one either way.

All that being said, I would not attempt the Pocket routine, as I don't think it's a good fit for this exact combination of inside/outside cutting. I'd strongly suggest a 2D Contour (simplest) or 3D Adaptive (Not so simple)

[Trigg3r]

Not near a PC with Fusion on at the moment but here's a screencast about contour selection, how to choose open or closed contours and how to reverse direction.

Basically if you click the red arrow, the other side of the contour selected will be cut. I

f you click again on the selected contour, you can edit the selection or choose open or closed contours.

HTH 🙂

[kb9ydn]

Not really sure what the deal is with this one but I've noticed that open contours tend to do some strange things sometimes.  So if you can it's best to use closed contours as much as possible.  Also it helps if you can use stock definitions to give hints about what areas to machine.

I did manage to select two open contours for that pocket but it still didn't work right so I decided to try a different approach.  The different approach is to select closed contours for the areas you don't want to machine, and then select the area you do want to machine as a stock contour.  This way you can use all closed forms which tends to be much more reliable.  It seems a bit counter intuitive at first but it's easy when you get the hang of it.

There does appear to be a bug in the selection behavior though, possibly caused by some error in the model.

C|

[Anonymous]

I see the result of what you did but I don't know how to get the "yellow" features. Any info links available?

thanks!

Tom

[LibertyMachine]

@kb9ydn I see what you did to get it to work. However, I'd argue that is not the proper way to go about it, as it's very counter-intuitive as to what needs to be done to accomplish the task. The "Pocket Selection" should be that; selecting pockets to machine. The "Stock Contours" are for defining where the stock is. You "tricked" it into working by reversing what was considered stock and what was pocket. Yes, it worked, but I'm not too certain that would be a method intended by the devs. Of course, if it works....

Although, I've seem them (developers) close up workarounds as they were unintended/undesired methods, leaving many people frustrated because that's how they learned to select something.

@Anonymous The "yellow" features come about by turning on Stock Contours and selecting the bottom of the pocket(s). You can actually go one step further and select BOTH and delete the previous pocket operation.

Again, while it works, I'm not to keen on this approach

[kb9ydn]

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@LibertyMachine wrote:

@kb9ydn I see what you did to get it to work. However, I'd argue that is not the proper way to go about it, as it's very counter-intuitive as to what needs to be done to accomplish the task. The "Pocket Selection" should be that; selecting pockets to machine. The "Stock Contours" are for defining where the stock is. You "tricked" it into working by reversing what was considered stock and what was pocket. Yes, it worked, but I'm not too certain that would be a method intended by the devs. Of course, if it works....

Although, I've seem them (developers) close up workarounds as they were unintended/undesired methods, leaving many people frustrated because that's how they learned to select something.

@Anonymous The "yellow" features come about by turning on Stock Contours and selecting the bottom of the pocket(s). You can actually go one step further and select BOTH and delete the previous pocket operation.

Again, while it works, I'm not to keen on this approach

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@LibertyMachine

What difference does it make?  At the end of the day all you're doing is selecting a boundary (the blue lines) and then telling it which side of the boundary to cut on.  If the boundary is closed and you pick the inside to be cut, everything inside of it gets machined (unless there are islands or stock contours to limit it more).  If the outside is picked then it will machine everything outside based on the selected stock contours.  If there are no stock contours then cutting the outside of a closed boundary would be an infinite area which obviously can't work.

An open boundary is really no different from a closed boundary, except that stock contours (or some other means to limit the area) will always be required so that you don't end up with an infinite area to cut.  I think where open pockets fall down is when they have two open boundaries and have to cut between those boundaries.  It seems to work fine when you only have a single open boundary; it cuts on one side or there other.  But with two open boundaries it can't seem to reconcile the two to find where to cut, even with stock contours as hints.

C|

[LibertyMachine]

The difference it makes is in the new user who has very little experience with CAD/CAM. 

There are dozens of little tricks, cheats and workarounds that can be made to do clever things that perhaps aren't intended. Perfectly acceptable for someone who knows what they are doing to utilize! Not so much for someone getting off the ground..

I'm looking at it by what exactly is expressed in tool tips, naming conventions and whatnot. What's the actual intent? Based simply on a textual level, Pocket and Stock seem to be self explanatory. If they were meant to be regularly treated interchangeably, they would most likely be called Boundary 1 and Boundary 2

And there has been more than one occasion where an unusual selection and definition method yielded perfect results. The catch was that wasn't the intended method, so when they tweaked an algorithm, it completely broke that method. Then the update goes through and you have people up in arms because they learned a method that was never intended and now it's broken, and on top of that, all the programs that have that operation are now invalid

And I agree, open areas and Pockets don't mix well. It's one of the easier examples to use when suggesting 3D Adaptive

[kb9ydn]

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@LibertyMachine wrote:

The difference it makes is in the new user who has very little experience with CAD/CAM. 

There are dozens of little tricks, cheats and workarounds that can be made to do clever things that perhaps aren't intended. Perfectly acceptable for someone who knows what they are doing to utilize! Not so much for someone getting off the ground..

I'm looking at it by what exactly is expressed in tool tips, naming conventions and whatnot. What's the actual intent? Based simply on a textual level, Pocket and Stock seem to be self explanatory. If they were meant to be regularly treated interchangeably, they would most likely be called Boundary 1 and Boundary 2

And there has been more than one occasion where an unusual selection and definition method yielded perfect results. The catch was that wasn't the intended method, so when they tweaked an algorithm, it completely broke that method. Then the update goes through and you have people up in arms because they learned a method that was never intended and now it's broken, and on top of that, all the programs that have that operation are now invalid

And I agree, open areas and Pockets don't mix well. It's one of the easier examples to use when suggesting 3D Adaptive

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The funny thing is I would say that it matters regardless of the user's experience level.  The field names should be as descriptive as possible of what the fields do.  In this case they are not, and I'm pretty sure I've argued before that they should be changed.  In fact, in HSMXpress the pocket selections are called "model" and not "pocket", which makes a lot more sense.  Although what's interesting is that in HSMXpress the only way you can get open pockets to work at all is if you draw a giant box around the whole thing, which makes no sense at all. 

As far as intent, how do we know for sure what the developers intend?  They hardly ever tell us directly.

C|

[Steinwerks]

@LibertyMachine 

@kb9ydn's method is not a cheat, it is intended behavior and how it has been in HSMWorks since forever AFAIK, as well as the original behavior all the way back in the CAM360 beta until they kept pulling obvious functionality out of it. In HSMWorks (and yes, it USED to be in Fusion) 2D Adaptive has a lovely little checkbox that says "Machine Cavities" and it works exceptionally well IMO:

These obviously aren't exactly the same, but they're real close:

Edit: On a hunch I went looking for something and found it in the Compare and Edit dialogue:

[daniel_lyall]

Curtis showed to do it that way, select what you don't wont to cut is what he called it.

[Steinwerks]

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@daniel_lyall wrote:

Curtis showed to do it that way, select what you don't wont to cut is what he called it.

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Exactly this. Here's a screencast I did in April last year showing it as well: