FreeCAD learning curve

Have some feature requests, feedback, cool stuff to share, or want to know where FreeCAD is going? This is the place.
tonydiethelm2
Posts: 33
Joined: Fri Oct 19, 2018 5:46 pm

Re: FreeCAD learning curve

Postby tonydiethelm2 » Thu Mar 14, 2019 6:00 am

If I may chip in...

I'm learning FreeCAD. I've been using it for simple 2.5D CNC projects, now starting to do more 3D stuff. I'm not deep into stuff.

Some of the GUI is not very clear....

An example... I wish to model a guitar neck along the Y axis. I choose to use a loft between two sketches. Easy peasy! I make a sketch in the XZ plane. I make another sketch in the XZ plane, and I change the offset attachment on one of my sketches to move it along the Y axis..... and that's not what happens. It moves along the Z axis. Huh? I search the forums. It seems that the offset is relative to the plane I made the sketch on. Ok, fine, but that's not intuitive, and not in the documentation.

I can use the Sketch -> Reorient sketch, and that IS intuitive. It presents the offset as a simple number and it works on the Y axis for my sketch in the XZ plane. It changes the attachment offset. Same thing, way more intuitive.

The learning curve is .... steep. The documentation is excellent for basic stuff, but once you stray off that path.... It gets hairy fast.

The biggest problem I'm finding myself having is not knowing what methodology to use on stuff. I'm fine reading up. It's gotten me this far! Often now though... I just want to know what the Best Known Method is. And that's hard to find.
chrisb
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Re: FreeCAD learning curve

Postby chrisb » Thu Mar 14, 2019 9:05 am

tonydiethelm2 wrote:
Thu Mar 14, 2019 6:00 am
It seems that the offset is relative to the plane I made the sketch on.
That's what the documentation says, but I admit, that I understood it was there only after I knew the behaviour. I have extended the docs, and would appreciate it, if you can have a look and add further improvements. https://www.freecadweb.org/wiki/Part_At ... ent_Offset
The docs got a bit out of balance, because I added not only an annotation to the general part of the subsection, but also to only the Z-value. I hope it's ok, because this is the most frequently changed value, as far as forum questions are taken into account.
I can use the Sketch -> Reorient sketch, and that IS intuitive.
For simple cases yes, but in fact the advantege of the attachment behaviour becomes clear, when you think about a skewed plane, to which the sketch is attached. Swapping Y and Z is very easy opposed to calculating the offset in 3D space for a sketch at a certain distance from a plane which is turned 20° around X, 30° around Y and 2° around Z axis.

Perhaps it is worth a feature request to combine the attachment dialog with the transformation tool.
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HarryGeier
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Re: FreeCAD learning curve

Postby HarryGeier » Thu Mar 14, 2019 10:08 am

chrisb wrote:
Thu Mar 14, 2019 9:05 am

Perhaps it is worth a feature request to combine the attachment dialog with the transformation tool.
++1
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NormandC
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Re: FreeCAD learning curve

Postby NormandC » Fri Mar 15, 2019 3:20 am

tonydiethelm2 wrote:
Thu Mar 14, 2019 6:00 am
I can use the Sketch -> Reorient sketch, and that IS intuitive. It presents the offset as a simple number and it works on the Y axis for my sketch in the XZ plane. It changes the attachment offset. Same thing, way more intuitive.
No, it's not the same thing. Reorient sketch will detach the sketch if it's actually attached, and place it floating in space. The Attachment utility actually attaches the sketch to a reference inside the Body. You may think the reference positioning is unintuitive, but it has to be that way, because the Body itself can be translated/rotated in reference to the global coordinates.

Granted, the attachment UI is not the easiest to grasp, with its 23 different modes of attachment, many of which will never be used by the majority of end users (the commercial software I use at work as 6 or 7 at the most).

tonydiethelm2 wrote:
Thu Mar 14, 2019 6:00 am
The learning curve is .... steep. The documentation is excellent for basic stuff, but once you stray off that path.... It gets hairy fast.
Welcome to parametric modelling. It's a complex subject. When companies purchase licenses for commercial software (which can cost easily upward to $4,000-15,000/license only for mid-range programs), they send their CAD operators to a 5-day 32-hour introductory course. In such a course you only learn the basics to get you going, the rest of the way you need to learn on your own. The documentation for these programs is not more detailed than FreeCAD's.

At some point, only experience can teach you what you need.

tonydiethelm2 wrote:
Thu Mar 14, 2019 6:00 am
I just want to know what the Best Known Method is. And that's hard to find.
More often than not there is no single "Best Known Method". In any case, it always depends on what type of modelling you want to do. Best practices for architecture work are totally different from mechanical design work. And I've not mentioned the intended manufacturing processes that can affect how you'll model and organize your stuff.