FreeCad - really just getting started

Lesson #8 is a bit tougher. Had to take a break from it for a day.

For some inspiration, I was looking at Joko Engineering Make This Cylinder Head. 4 hour video. Step by step (at a far faster rate than I can do now) build up of a cylinder head. Sat through an hour of it. Amazing! Have learned some of the concepts so I'm actually understanding most of the process.

Have to get back in the saddle again...
 
Lesson 8. Oof, my choice of a picture to trace was unfortunate. I chose a jet to trace, but I didn't know that I needed the other orthogonal views of it, to make a rough 3d model. It would have been helpful to have gotten a link to the same pictures that were used in the video, or have some stated criteria for the pictures. I watched the video this time without being able to parrot his moves.

Still having problems with closing the polyline. Only half of the line is continuous, but the sketch doesn't show the issue. Wish I could figure this out, as this will come back and bite me. The Sketcher solver is stating Undefined degrees of freedom. For the life of me, I can't find the offending problem. Root problem might be the color change is too subtle for me to detect when I connect the dots. Then I place a dot (line) which is disconnected from the previous one.

There's some sort of bug, or, more likely, I'm not doing something right. I selected the whole polyline then selected "produce a closed shape". Then I get a message there are redundant constraints. It asks to remove redundant constraint 47 & 48. However, under Constraints, I only have 46 constraints. If I start all over again, and unclick auto remove redundants, I can see the 47 & 48. I can unselect them, and I can deactivate them, but the solver message still complains about those constraints. If I delete the constraint, the solver still complains. Don't know what to do next. Can't seem to fix the sketch. You'd think tracing a part or picture wouldn't be hard.

Let's see if I can attach the project. v0.19. If anyone could take a look and offer a suggestion. Curiously, the first part of Lesson 8 was a snap.
 

Attachments

  • Beginner8.FCStd
    2 MB · Views: 8
I wouldn't dwell on #8. That's more about showing you a method, but it would be extremely time consuming to try to do it effectively if you haven't done it before. There are some good tips on how to use the interface in #11 and that will help you a lot. I sort of breezed through #8 because I had a pretty good idea it was going to take time and it's something that you probably won't need to do initially. Understanding the boolean operations are important, but using the image sketch to create a 3D model is a much more advanced skill and was probably just shown as a 'teaser' to show you the potential.

FWIW, I'm plodding through the series as well. I'm currently on #16, looking forward to #17, which I think is an important one (Assembly).
 
Agreed. Don't sweat parroting 8. In fact, as a fellow beginner I would suggest stopping and getting very comfortable with Parts Design and Sketcher. You may watch 13, which covers Sketcher some more.
 
I wouldn't dwell on #8. That's more about showing you a method, but it would be extremely time consuming to try to do it effectively if you haven't done it before. There are some good tips on how to use the interface in #11 and that will help you a lot. I sort of breezed through #8 because I had a pretty good idea it was going to take time and it's something that you probably won't need to do initially. Understanding the boolean operations are important, but using the image sketch to create a 3D model is a much more advanced skill and was probably just shown as a 'teaser' to show you the potential.

FWIW, I'm plodding through the series as well. I'm currently on #16, looking forward to #17, which I think is an important one (Assembly).
Thanks for the advice. I understood the boolean operations part. Really it's the sketching part that still is kicking me. I don't know if it's astigmatism, or lower visual acuity, but I'm having some troubles with closing the curves/lines at times. cant join the lines.jpg
How can I join these endpoints? Nothing seems to be working for me. The image tracing isn't relevant.
 
Last edited:
How can I join these endpoints? Nothing seems to be working for me. The image tracing isn't relevant.
Watch #11, it goes into that. You'll just get frustrated if you try to 'finish' #8.
 
Ok. So should I next do #9?
Definitely. #9 is very useful. Just don't let yourself get bogged down on any of them. Watch and absorb. Try to play along, but sometimes he just does things like he's getting lost in the task rather than the syllabus. I skimmed some of 10 & 11, and 13, but the rest are good to follow the detail.
 
Lesson 8. Oof, my choice of a picture to trace was unfortunate. I chose a jet to trace, but I didn't know that I needed the other orthogonal views of it, to make a rough 3d model. It would have been helpful to have gotten a link to the same pictures that were used in the video, or have some stated criteria for the pictures. I watched the video this time without being able to parrot his moves.

Still having problems with closing the polyline. Only half of the line is continuous, but the sketch doesn't show the issue. Wish I could figure this out, as this will come back and bite me. The Sketcher solver is stating Undefined degrees of freedom. For the life of me, I can't find the offending problem. Root problem might be the color change is too subtle for me to detect when I connect the dots. Then I place a dot (line) which is disconnected from the previous one.

There's some sort of bug, or, more likely, I'm not doing something right. I selected the whole polyline then selected "produce a closed shape". Then I get a message there are redundant constraints. It asks to remove redundant constraint 47 & 48. However, under Constraints, I only have 46 constraints. If I start all over again, and unclick auto remove redundants, I can see the 47 & 48. I can unselect them, and I can deactivate them, but the solver message still complains about those constraints. If I delete the constraint, the solver still complains. Don't know what to do next. Can't seem to fix the sketch. You'd think tracing a part or picture wouldn't be hard.

Let's see if I can attach the project. v0.19. If anyone could take a look and offer a suggestion. Curiously, the first part of Lesson 8 was a snap.

I wouldn't spend too much time on this lesson. It's just to show a technique. I did have a go with your file and was able to close the sketch and pad it.

You need to make sure all you points are coincident. I saw some points that were very close together, but not coincident. I would use the polyline tool and go for it in one continuous loop around the jet. Make sure to close the sketch by ending exactly where you started. The points will change color when they are coincident. Use the highlighted tools below to close any that are not coincident after selecting both points.

Beginner8_tools.jpeg
 

Attachments

  • Beginner8.FCStd
    2.1 MB · Views: 1
The points will change color when they are coincident. Use the highlighted tools below to close any that are not coincident after selecting both points.
Hmmm, is that a setting in 'preferences'? With my new installation the point colors don't change, coincident or not.

Oh, I just tried a sketch and I can see the vertex change color as I move it over another vertex. Statically all the vertices are the same color.
 
Last edited:
Back
Top