CASTING MODEL

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chrisb
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Re: CASTING MODEL

Postby chrisb » Mon Jun 29, 2020 4:13 pm

ppemawm wrote:
Mon Jun 29, 2020 1:56 pm
6. I have no idea how you got Pad007 as a child of Hole001. Perhaps that is a new feature of which I am not aware but it sure does look confusing.
In the same way as you can pad or pocket a face you can "hole" a face:
Snip macro screenshot-b224c6.png
Snip macro screenshot-b224c6.png (10.77 KiB) Viewed 348 times
For the attached model I selected the Pad and not the sketch and created a hole. It looks indeed rather weird.
Attachments
holeFromPad.FCStd
(12.67 KiB) Downloaded 7 times
Dushyant007
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Re: CASTING MODEL

Postby Dushyant007 » Mon Jun 29, 2020 4:50 pm

3. Sketches should always be fully constrained otherwise expect some problems later in the tree if any changes are made.
I mostly use, Symmetric Constraint to keep the sketch in Center, and when it is constrained follwed by Horizontal and Verticle constraint from Origin, it doesn't allow me to make it fully constrained or gives an error. I don't know what is an issue and what makes it difficult to fully constrained.
Dushyant007
Posts: 49
Joined: Wed Jun 24, 2020 8:15 am

Re: CASTING MODEL

Postby Dushyant007 » Mon Jun 29, 2020 4:58 pm

If model seems complex or deteriorate is just because the drawing of this model had incomplete views and some dimension were missing, even dotted line was not there in 2D drawing. So I made this MODEL BY JUST 'GUESSING'.
Dushyant007
Posts: 49
Joined: Wed Jun 24, 2020 8:15 am

Re: CASTING MODEL

Postby Dushyant007 » Mon Jun 29, 2020 4:59 pm

If model seems complex or deteriorate is just because the drawing of this model had incomplete views and some dimension were missing, even dotted line was not there in 2D drawing. So I made this MODEL BY JUST 'GUESSING'.
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ppemawm
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Location: Manhattan New York

Re: CASTING MODEL

Postby ppemawm » Mon Jun 29, 2020 5:24 pm

Dushyant007 wrote:
Mon Jun 29, 2020 4:50 pm
3. Sketches should always be fully constrained otherwise expect some problems later in the tree if any changes are made.
I mostly use, Symmetric Constraint to keep the sketch in Center, and when it is constrained follwed by Horizontal and Verticle constraint from Origin, it doesn't allow me to make it fully constrained or gives an error. I don't know what is an issue and what makes it difficult to fully constrained.
Looks like you could use a review of the basics in Sketcher. Please see Chrisb's excellent tutorial on the Sketcher workbench. It is the foundation to sound parametric models: https://forum.freecadweb.org/viewtopic.php?f=36&t=30104
Last edited by ppemawm on Mon Jun 29, 2020 6:32 pm, edited 1 time in total.
"It is a poor workman who blames his tools..." ;)
chrisb
Posts: 25206
Joined: Tue Mar 17, 2015 9:14 am

Re: CASTING MODEL

Postby chrisb » Mon Jun 29, 2020 5:37 pm

Dushyant007 wrote:
Mon Jun 29, 2020 4:50 pm
I mostly use, Symmetric Constraint to keep the sketch in Center, and when it is constrained follwed by Horizontal and Verticle constraint from Origin, it doesn't allow me to make it fully constrained or gives an error. I don't know what is an issue and what makes it difficult to fully constrained.
I had a look at your first sketch. As you have experience in other systems you may extrapolate the hints to other sketches. If you have questions, ask back.

- minimize the number of dimensions, geometry becomes clearer using geometric constraints
- especially don't use 0mm dimensions, they clutter the view
- use point-to-point tangency if applicable, your point-on-object constraint didn't even make the sketch closed:
Snip macro screenshot-5a559c.png
Snip macro screenshot-5a559c.png (4.87 KiB) Viewed 312 times
- similar with coincidence, if applicable:
Snip macro screenshot-478603.png
Snip macro screenshot-478603.png (1.39 KiB) Viewed 312 times
I upload the file with the fully constrained first sketch for your further investigations.

As I don't know SolidWorks and you claimed in another post to be an expert, I guess you tried to transfer your workflow to FreeCAD. May I ask if SolidWorks supports such sketches for padding, or do they have a support mechanism to find the missing constraints automatically?
Attachments
CastingBodyFirstSketch.FCStd
(5.8 KiB) Downloaded 8 times
Dushyant007
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Re: CASTING MODEL

Postby Dushyant007 » Tue Jun 30, 2020 3:21 am

May I ask if SolidWorks supports such sketches for padding, or do they have a support mechanism to find the missing constraints automatically?
Yes, it has. It is called FULLY DEFINE SKETCH, in which if there are any entities forgotten to give dimensional constraint, it will add automatically and the whole sketch turned out from Blue to Black color.

However, it is limited to dimensional constraint only, not with the geometric constraint like Tangent, Parallel, Equal or Perpendicular, etc.
SW.png
SW.png (32.63 KiB) Viewed 227 times
SW1.PNG
SW1.PNG (35.13 KiB) Viewed 227 times
You can check my other models on Grabcad, where there are only 5-6 models I have uploaded on that platform. That model was uploaded when I was student :), my latest model is this one >>> https://grabcad.com/library/pump-casing-8 (Modeled with SolidWorks).

Surface modeling is not my area of expertise. Part modeling of machine components, jigs and fixtures, and plastic spacer are the main concern.
My enthusiasm is for Surface modeling and part of my hobby as a designer.
chrisb
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Re: CASTING MODEL

Postby chrisb » Tue Jun 30, 2020 7:59 am

I'm rather glad that FreeCAD only shows non fully constraint geometric elements without adding dimensions, because I would judge the result as a poorly constrained sketch. Adding dimensional constraints would not connect the points, but rather suggest everything is ok, while it isn't at all.
In FreeCAD you have the "Validate Sketch" tool, which can find and repair missing constraints though. Please note that it may add redundant constraints.
Dushyant007
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Re: CASTING MODEL

Postby Dushyant007 » Tue Jun 30, 2020 9:52 am

chrisb wrote:
Tue Jun 30, 2020 7:59 am
I'm rather glad that FreeCAD only shows non fully constraint geometric elements without adding dimensions, because I would judge the result as a poorly constrained sketch. Adding dimensional constraints would not connect the points, but rather suggest everything is ok, while it isn't at all.
In FreeCAD you have the "Validate Sketch" tool, which can find and repair missing constraints though. Please note that it may add redundant constraints.
I saw that on the wiki page. So it does find and repair but still, we have to add dimensional constraint manually. The major point is that Validate Sketch only works when it is not in 'edit mode' whereas in SolidWorks one can do that while creating a sketch, even with 3D sketch.

Reminding of constraint, I would like say that there is an issue with Tangent constraint. In almost every parametric software, when one or more than one angular line is a tangent with the circle, it also makes 'coincide with circular path or any entities' (similar to 'fix a point onto' in FreeCAD) which means it joins as an intersection of a circular path AND allows to Trim a circle between that intersections.
chrisb
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Joined: Tue Mar 17, 2015 9:14 am

Re: CASTING MODEL

Postby chrisb » Tue Jun 30, 2020 11:52 am

If you handle it correctly FreeCAD does the same, have a look at the documentation. I am no friend of too much automatism, so I am very happy with the way it is, which is easy and completely under my control.