Newbie having trouble with sketcher

[drmacro]

1) the link in your signature doesn't actually lead to a PDF, it leads to your GitHub account. The link to the document is:

No it leads to a particular page of my gihub account where there are multiple pdf documents about learning FreeCAD.
The user can decide which he/she wants to read first...the document prefixed with the number 1 being a logical place to start.

2) the documents spends a lot of time about what is not ("this document is not for the seasoned "), and not so much about "So where do you start to design a given idea ? " Why begin to talk about the Draft WB and tell to skip it ? It's confusing. Also, this shouldn't be a course on 3D modeling ("Designing things with a CAD program entails a variety of skills " !!!), but a beginner's guide to this tool (FreeCAD) for experienced 3D designers. You could add to your intended audience introduction that some per-requisits about 3D design is a must-have.

Well you need to start somewhere. And the Draft workbench is in a section with the title Some History...

Clearly the entire series is not addressed to seasoned veterans as yourself. It intentionally makes this abundantly clear.

I suspect your confusion is related to your vast long term experience with FreeCAD. Many new users have used these documents and gone out of their way to contact with me with thanks for bringing them clarity they did not find elsewhere.

3) I'd suggest as a a first lesson: import STEP files from Internet, and learn how to visualize them, rotate them, zoom, save, re-open, change colors, transparency, select objects, faces, edges .... Get used to the interface, tree-view, property-view, play with the toolbars ... Learn to use FreeCAD as a reader before using it as an editor.

4) as second lesson, create a sketch and draw on it, make circles, squares, lines, learn the constraints ... (switch to sketcher WB, create sketch, assign to XY plane, draw). No need to mention PartDesign or Part or Draft WB for this

5) only after 3) and 4) would I go to actually making a part

Some version of all of these may be desirable. And, as we see here and in other social media, the use of STEP, and other import/export types, certainly sees a lot of questions. The problem is, for better or worse, most new users are anxious to get to the making things part and assume they can pick up the different views, color setting, etc. as they progress. Thus the series gets quickly to the point of making a something that exemplifies many of the tools needed to sketch, pad, and create voids. The series also quickly introduces TechDraw to avoid the new users getting lost when they find Drawing workbench and give a taste of the overall process.

Are these three documents the end all and be all of a complete course on all of the capabilities and intricacies of FreeCAD? Nope.
Would 30 documents meet that description? I suspect the number of pages in the wiki far exceeds 30, so yes there is a long way to go.

I suspect a How to STEP treatise could easily exceed 3 documents.

In any case, thanks for your opinions and ideas.

[GeneFC]

Many new users have used these documents and gone out of their way to contact with me with thanks for bringing them clarity they did not find elsewhere.

Sorry, I should have included your tutorials in my post above.

I consider them very good.

Gene

[OldBikerPete]

...Errmmmmm. How do I add a constraint?

Peter. Who has devoted at least 20 hours to this problem so far with zero noticeable progress.

Did you spend 15 minutes reading the first pdf in the link in my signature as I mentioned previously?

If it did not answer this question, I would like to know how to improve it...

Yes, I did read all of that. It took me a lot longer than 15 minutes. I don't know how much of that I retained.

I did notice that the pdf covered the general flow of work very well BUT. For someone like me, it needs to cover a smaller range of operations in the tiniest itsy-bitsy detail. I know from experience in other subjects that this can be very hard for someone who is extremely practiced in a subject.
For example: the button which toggles the sketch editor in and out of construction mode - how do you find out which mode it's in? When drawing a sketch made up of different elements, when do you zoom in and make sure the elements join each other properly. How do you do that (In AutoCAD it's easy)? How do you add constraints? At what point are constraints added? If you finish up with too many degrees of freedom, how do you fix that?

I suggest that you draw a very simple sketch made up of a few different elements and document every mouse movement, every mouse click, every keypress WHILE YOU ARE DRAWING IT. And when I say 'document', I mean cover what, why and how.

A thought occurred to me while writing the above sentence. FreeCAD can record macros, right? Can those macros be exported as text? If so, perhaps you could record yourself drawing that sketch and the resulting text would be fully inclusive and only require annotation to be a useful guide. If this cannot be done as of now, perhaps its an idea worth writing into the code.

Peter.

PS. I have also read a bit of the wiki, watched a few videos, read some tutorials. The trouble with all of these is that they cover a range of operations, most of which I'm not interested in right now, so my mind goes into throw-away mode and I don't retain the snippets that would be useful right now. What I think would be more useful is a large number of small tutorials on very limited operations - EG: draw a small sketch, use pad on a sketch, use revolve on a sketch. All in the tiniest detail.

[GeneFC]

I have also read a bit of the wiki, watched a few videos, read some tutorials.

That is likely 90% of the problem. You need to actually work the tutorials, step by step, or they will quickly be lost and forgotten. Perform each step and compare your results with the tutorial. If they don't agree try again until they do.

That is one reason I like written tutorials much better than video tutorials. You can stop for as long as it takes to get it right. With a video the tendency is to go on to the next step without really understanding where you are.

I started with a tutorial that is still in the wiki, updated for the current FreeCAD code.

https://wiki.freecadweb.org/Basic_Part_Design_Tutorial

I must have tried it 5 or 6 times before I got it right. It takes practice.

Gene

[OldBikerPete]

I have also read a bit of the wiki, watched a few videos, read some tutorials.

That is likely 90% of the problem. You need to actually work the tutorials, step by step, or they will quickly be lost and forgotten. Perform each step and compare your results with the tutorial. If they don't agree try again until they do.

https://wiki.freecadweb.org/Basic_Part_Design_Tutorial

I must have tried it 5 or 6 times before I got it right. It takes practice.

Gene

Language. I did work that tutorial drawing my own sketch, following it through to the point where my sketch disappeared off the 3D view.
Read my earlier post where I said this.
As has been explained, that happened because 1> I had toggled out of construction mode (probably by clicking more than once) because the tutorial did not explain how I could tell whether or not I was in construction mode 2> the segments of my sketch did not meet properly even though I had 'snap to grid' enabled. I have encountered this in AutoCAD and expected it but the Tutorial does not cover how to correct this. 3> probably half a dozen things I've done wrong that are not covered in the tutorial because it does not go into sufficient detail.
I have gone through the motions again several times with the same result, obviously making the same mistakes.

[OldBikerPete]

Job done. Proof attached.
Lessons learnt.
1> The editor opens in non-constructing mode - one can tell that it is in non-constructing mode because the little drawing-element icons are shown as outlines between dots rather than solid lines between dots. You need to do the drawing in non-constructing mode. Constructing most is a feature for ADVANCED use.
2> When adding an element to a sketch, the little red dot that terminates the previous element turns yellow when the cursor hovers exactly (well, not quite - more on that later) over it. Left-clicking the mouse at that time exactly (see later) aligns the ends of the two elements.

These details are fundamental to FreeCAD sketching and should have been covered in the wiki and any basic tutorials
BTW. A decent definition of constructing mode and its uses should be announced BEFORE its possible activation is mooted.

3> My sketch was drawn in the XZ plane and needed to revolve around the Z axis, so X and Y axes needed to be left as 0.00 and the Z axis set non-zero for that to happen. Lots of questions for other times are raised here.

BUGS:
In the initial dialog which starts the editor, the grid defaults to 70mm which is OK. I changed it to 0.1mm and made sure that the 'snap to grid' was activated because it suited my job. I then cleared the 'Show Grid' box. As expected, the non-visible grid was snapping but not quite as expected - more later. The point here is that, on one occasion I accidentally deactivated the editor. When I re-activated the editor, the grid had been re-set back to 70mm, OK once I figured out what had happened but it should have restored the most recently used grid IMNSHO.

Doing the drawing involved a lot of zooming in to check that the segments joined properly and clicking on the centre-wheel of the mouse to drag the drawing around. I found it most disconcerting and ^%$#^%$#&*%& inconvenient when said dragging often had the sketch revolving around multiple axes in seven different dimensions!! There's gotta be a way of disabling that hidden somewhere.

Finally, there seems to be some sort of cumulative rounding error in the grid. As an example, I placed an arc centre point at Z=58.0,X=48.0 joined to a line segment ending at Z=60,X=48 then drew the arc 90.0 degrees and finished up with an arc 2.0 mm radius ending at Z=58.0,X=50.1 somewhere along the line errors totalling 0.1mm had crept in.

Well, problems solved for now, so thank you all for trying your best for me. I'll be back next time I have a problem.
Peter.

[chrisb]

Did you have a look at my Sketcher lecture? It my be repelling seeing the number of pages, but you can omit some of them on first reading. I recommend to read up to section 5 "Common usage" and then a bit more about some of the geometric elements, until you have the feeling "oh my god, this is boring, it is almost always the same". Then skip to part III and read the first sections about constraints.

[chrisb]

2> When adding an element to a sketch, the little red dot that terminates the previous element turns yellow when the cursor hovers exactly (well, not quite - more on that later) over it. Left-clicking the mouse at that time exactly (see later) aligns the ends of the two elements.

Here is an extract from the lecture mentioned above:

Bildschirmfoto 2021-09-21 um 08.06.45.png (26.97 KiB) Viewed 707 times

There is really a load of information in the wiki and around it. It is nearly impossible to present it in a more suitable way, because as soon as we expose something more prominently, other things are more in the background and then someone asks to present them more prominently too ...