FreeCAD scoffs at my cuts...

[billfromnet]

The forum does not allow me to attach the 2.5MB .fcstd. I'm trying to subtract some volume from a solid with a boolean op in the Parts menu. Specifically, I'm trying to take a bite out of leftGasket with object Cylinder. The resulting Cut012 renders on screen with lines showing where the surface of Cylinder intersect the surface of leftGasket, but the volume is not removed. I don't understand why. I'd appreciate any clues as to what to look for.

Screenshot_20180620_105658.png (190.6 KiB) Viewed 1130 times

[billfromnet]

Further to this, it's probably worth noting that I did this successfully in an earlier revision. The problem occurred after I modified the sketch underlying leftGasket (leftBase). I've checked leftBase for indications that it is not closed or some such condition, but I haven't found success. I need diagnostic guidance.

[TheMarkster]

If you hide the cylinder (select it in the combo view and press spacebar) does the gasket show to be cut the way you intended? If so, then that is the way it is supposed to work, except the cylinder should have been automatically hidden for you. If you hide the cylinder and the gasket remains full (no hole) try doing the cut again. Select the base object first, then the object you want to remove, and do the boolean cut operation.

[oldmachine]

don’t know if the problem is:

•You’re in the “Start” workbench, not the “Part” workbench.
•The “Visibility” on the "Extrude017” is false (turn it on from the “View” button lower left of View/Data panel.

•Consider remaking the part using the PartDesign workbench - it could be done in less than a Heartbeat of time…

[billfromnet]

@TheMarkster - only the intersection of surfaces is depicted when the Cylinder display is suppressed. The volume is not removed...

Screenshot_20180620_120634.png (179.14 KiB) Viewed 1113 times

Repeating the operation...

Screenshot_20180620_120634.png (179.14 KiB) Viewed 1113 times

Produces the same result...

Screenshot_20180620_120634.png (179.14 KiB) Viewed 1113 times

[billfromnet]

@oldmachine:

•You’re in the “Start” workbench, not the “Part” workbench.

Because I restarted the program after removing extraneous objects in order to simplify this forum post.

•The “Visibility” on the "Extrude017” is false (turn it on from the “View” button lower left of View/Data panel.

Indeed yes, visibility is off. I typically toggle visibility with the space bar when selected from the hierarchy. I don't understand what you are driving at.

•Consider remaking the part using the PartDesign workbench - it could be done in less than a Heartbeat of time…

Perhaps you could do it in a heartbeat. I'm a novice struggling with FC idiosyncrasies. I'm trying to understand why it fails here. I do not wish to fire a shotgun once again, but would prefer to gain proficiency.

[oldmachine]

Visibility True/False sets whether a feature is visible or not.

FYI - The Features in the Part workbench (IMO) are the foundation of 3D solid modeling and, sometimes are useful but, limited in usefulness for making modern-day models (some will, no doubt argue).
Modern-day CAD programs, such as SolidWorks, Pro-E...etc eliminate that limitation and the PartDesign workbench is the Better option to use - especially if just starting (meaning, if going out to learn Target Shooting, why start with a Flint/Powder gun when you've got a Glock in your hand)... Crude analogy

I don't know the dimensions of your part but, the attached is an example of doing it in PartDesign. Note: would have been more useful to use lines and radius/circles but, I used B-splines. However, whether using line/curve/bsplines... the approach is the same... (and the file is much smaller)

[billfromnet]

Thank you for your response. As I indicated, I have successfully made this cut in a prior model with the Part WB. I've also played around with Part Design WB and although I appreciate some of its features, I deemed its complexity unwieldy for my purposes. Some of the restrictions imposed seemed arbitrary and annoying. For example, I can extrude in a negative direction in Part, but cannot pad in a negative direction in PD, IIRC. I also was stumbling over the structural restrictions related to the use of bodies and related components. And frankly, as much as I like FC and appreciate all the work done to develop it, I'm finding the UI somewhat incoherent as a package. That I would be advised to switch tools to solve this problem is testament to the fog that surrounds it.

But all that does not really matter. A qualified Glock user ought to be able to figure out how to use a flintlock rifle, or otherwise shouldn't play with guns. If I'm getting confused using the current tool, I need to understand the problem and understand the tool.

Do you have any clue about why my operation might be failing, or are you only trying to convince me to adopt your personal work style?

[bejant]

@billfromnet, please upload your file to a file hosting service (like Dropbox, where we don't have to register to download your file) so we can troubleshoot it.

[oldmachine]

Your points are understood…

Regarding gun: My point was/is, if starting out (as you indicated) I suggest not starting with Flint/Powder - move to that after you can shoot a Glock. And, which would end up being your ‘go-to’ tool/gun?

I cannot say anything about your model as it’s not posted (and, not posted because the file is so large due to using Features in Part workbench).

Agreed - user interface can be/is not necessarily quick to learn but, neither are piano/guitar but, like a long walk, it starts with first step.

There are some aspects of Part wb, such as making a Helix that are not available (yet) in PartDesign but, 80% of PartDesign wb might be worth your time… plenty of YouTube vids…

Of course, it’s all about your needs and I’ll move on after suggesting ‘open my previously attached file’ and play around with it (edit the sketches )- you’ve already invested more time in trying to solve the issue than it would take to understand something new, like PartDesign…

Extrude in Negative direction? There is a ‘Reverse’ direction checkbox when extruding in PartDesign… but, you’d only know that if spending a few moments exploring…

best of luck... Oh, it seems more user-botherome to need to upload a Part-based file to another site... Moving on... now