Please Critic My Machining Strategies for this part

[JerryFlyGuy]

Have you tried creating a sketch and extracting the edges of the surfaces you want to work on and creating your own boundry that way? I've always found the 'automatic' type boundrys to not be optimum and sometimes down right un-usable. If you created a sketch on the part showing the region you want to machine on this might have better results than selecting surfaces.

At worst HSM while working on these sides like this may not be the best option [at least for a one off part] if it's a production part [runs of hundreds or more] then it might be worth beating on to get it to work..

Keep us posted..

J

[MechanoMan]

Originally Posted by JerryFlyGuy Have you tried creating a sketch and extracting the edges of the surfaces you want to work on and creating your own boundry that way? I've always found the 'automatic' type boundrys to not be optimum and sometimes down right un-usable. If you created a sketch on the part showing the region you want to machine on this might have better results than selecting surfaces.

I'm not quite sure what you mean. How would you do that?
I'm doing the Select Faces most times, and let it generate boundary loops out of it (which it didn't do correctly). Are you saying draw loops manually in SW and try to bring them into SolidCAM?

I'm seeing where the non-HSM 3DM ops aren't running into this bug, so maybe I'll use that. Except the non-HSM has a completely different bug, where it will calculate the boundary totally wrong for certain curved surfaces, which appears to be a failure to use the Tool On Working Area and Offset fields AT ALL when doing Working Area->Work on Selected Faces->Drive Faces. It's there but has no effect on processing no matter what goes into it. Thus it generates an inconsistent, junk path on concave (and sometimes even vertical) surfaces because the surface edge is exactly on the boundary, sometimes it steps off the edge and machines all or partway down and sometimes it doesn't, probably depending on how the faceting got calculated internally. Basically it's viewing the boundary as the very edge of the face, but a face which goes vertical (or undercuts) has a conflict as to whether it sees the face edge as inside the boundary and calculates Z-level as the bottom (desired), sees the boundary before the edge and stops before it goes vertical, or drops to some totally unpredictable Z-value. Failing to go down to the bottom means the wall won't get machined which was essential. The resulting toolpath is basically noise.

And that's apparently because the Tool on Working Area isn't being used. See this is sort of what you'd expect from 0 offset, but giving it any positive value should have put the boundary past the face edge and solved it. You can give it any offset you like and it has no effect. In fact I can change to Internal, and give it a negative value larger than the face's width, which should keep ANY toolpath from being generated. Still generates. The field is totally unused.

And I've tried every single option in the whole operation, anywhere, nothing will fix this problem.

So I'm kinda thinking HSM for the curves that the 3DM can't do right, and 3DM for the straights that HSM can't do. Wow, that's kinda messed up but it does seem to be the situation and the answer.

[MechanoMan]

Huh... ok... check out this workaround I discovered:

So:
1. 3DM won't work consistently on selected FACES which go vertical, because the Offset option doesn't apply properly.
2. The 3DM "Working Area" option didn't work because it works by defining a boundary via Solidworks edges. But picture a cylinder on its side, stuck to a wall. I want to go around the cylinder, but there is no "edge" on the side of the cylinder wall anywhere. There is nothing to specify. This option will not do what needs to be done!
3. When using HSM, when you Select Faces, you get these broken loops which HSM will totally screw up on. However, it turns those faces into a Boundary Loop in the process which gets thrown onto the main, shared list of closed Loops.
4. THAT Loop, created in the HSM interface, can then be selected for a 3DM operation as the Working Area. Now that it's a Loop and not Selected Faces anymore, the 3DM's Offset option will finally work, and the 3DM works beautifully!

[JerryFlyGuy]

Mecho sorry, was away for the weekend. Just to clarify, to put a sketch in like my pic there and use that as geometry just means you jump over to SW [at the top of the feature tree] and add a sketch.. as simple as that..

Also, I've not tested it but the software SHOULD use the profile edge on your cylinder example to create a work area boundry... not nesc a profile boundry you can machine off off, because it's not really an 'edge' that you can select.. but it still should work as a work area boundry.

Fwiw

J

[MechanoMan]

Originally Posted by JerryFlyGuy Also, I've not tested it but the software SHOULD use the profile edge on your cylinder example to create a work area boundry... not nesc a profile boundry you can machine off off, because it's not really an 'edge' that you can select.. but it still should work as a work area boundry

But it's not possible. When selecting Contours, they have to be made of lines. You can't select a surface by this method. A cylinder on its side, calling 0 deg straight up, we'd want to select a line at 90 deg, the top face, and 270 deg as our Work Boundary. But that's not possible, there's no lines there to select because it's a continguous surface. The top face has a line of course.

[JerryFlyGuy]

I think we're saying the same thing..

I agree that using the edge of the cylinder would not be possible in selecting a profile however if in constraints boundry you select the "auto of part" [I'm paraphrasing as I'm not in front of SC to copy it directly]

Then it should put in a boundry around the whole part so it has a work zone only.. I'm pretty sure I've done this in the past on a similar part [infact I know I have] and it worked then..

Fwiw

J

[MechanoMan]

Originally Posted by JerryFlyGuy I think we're saying the same thing.. I agree that using the edge of the cylinder would not be possible in selecting a profile however if in constraints boundry you select the "auto of part" [I'm paraphrasing as I'm not in front of SC to copy it directly] Then it should put in a boundry around the whole part so it has a work zone only.. I'm pretty sure I've done this in the past on a similar part [infact I know I have] and it worked then.. Fwiw J

That it does. That'll work for HSM, if you indeed want to do the entire part. 3DM, I don't think I've seen how to do that, but it's beside the point because I don't want to select the whole silhouette.

[JerryFlyGuy]

If your wanting to only work on one section of the model vs the whole thing then you'll have to add a sketch [re: the picture I marked up] and then select that as your boundry.

Also, you can make a cylinderical wall into a profile [to machine along]. Orientate the model as it is in on the mill and in the plan view [X/y Plane Perp to the Z axis] insert a sketch and select the face of the cylinder and press "convert entities" it will create a profile of the outside perimeter of the part. Then you can use that for your profile.

One thing about CAD/CAM is if there is one way to do it.. then there's usually many different ways to get to the same result..

J

[Brakeman Bob]

Originally Posted by JerryFlyGuy One thing about CAD/CAM is if there is one way to do it.. then there's usually many different ways to get to the same result..

Amen to that.