Making lines for construction on an imported sketch

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lesthegringo
Posts: 19
Joined: Wed Nov 24, 2021 5:46 am

Re: Making lines for construction on an imported sketch

Post by lesthegringo »

Thanks - just tried using sketcher, and now the snap toolbar is not available, whereas before it was ...

Hopefully this time the screenshot has attached

Cheers

Les
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drmacro
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Re: Making lines for construction on an imported sketch

Post by drmacro »

Snap is a Draft workbench tool. It is not available in Sketcher.

The workflow with sketcher is to define the general shape, then use constraints to set the size.

In Sketcher use the polyline tool. It makes end vertexes coincident automagically.
Favour geometric constraints (horizontal, vertical, tangent, etc.) over dimensional constraints.
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Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
lesthegringo
Posts: 19
Joined: Wed Nov 24, 2021 5:46 am

Re: Making lines for construction on an imported sketch

Post by lesthegringo »

Thanks, so how do I select midpoint for the centre of an arc if there is no midpoint snap?

Cheers

Les
drmacro
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Re: Making lines for construction on an imported sketch

Post by drmacro »

lesthegringo wrote: Wed Nov 24, 2021 3:42 pm Thanks, so how do I select midpoint for the centre of an arc if there is no midpoint snap?

Cheers

Les
You add an arc and add a symmetry constraint to the center vertex.
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Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
lesthegringo
Posts: 19
Joined: Wed Nov 24, 2021 5:46 am

Re: Making lines for construction on an imported sketch

Post by lesthegringo »

Right, thanks.... a lot more complicated than SW, QCAD, Autosketch etc.....

I may reconsider my move from SW32 bit!

Cheers

Les
chrisb
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Re: Making lines for construction on an imported sketch

Post by chrisb »

drmacro wrote: Wed Nov 24, 2021 4:50 pm You add an arc and add a symmetry constraint to the center vertex.
This can be done even easier: select the line and the point and create the symmetry.
lesthegringo wrote: Wed Nov 24, 2021 6:40 pm I may reconsider my move from SW32 bit!
If you are interested, you may look at the sketcher document in my signature.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
drmacro
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Re: Making lines for construction on an imported sketch

Post by drmacro »

lesthegringo wrote: Wed Nov 24, 2021 6:40 pm Right, thanks.... a lot more complicated than SW, QCAD, Autosketch etc.....

I may reconsider my move from SW32 bit!
You asked how to do it in FreeCAD.

Both @chrisb and I explained how it is done in two different ways.

Alas, this is FreeCAD, not SW, QCAD, Autosketch etc., unfortunately.
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
chrisb
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Re: Making lines for construction on an imported sketch

Post by chrisb »

It could be an interesting new autoconstraint to create a symmetry constraint if a point is near the center of a line.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
drmacro
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Re: Making lines for construction on an imported sketch

Post by drmacro »

chrisb wrote: Wed Nov 24, 2021 10:10 pm It could be an interesting new autoconstraint to create a symmetry constraint if a point is near the center of a line.
There are plenty of constraints that are present in other software that would be of interest, midpoint, concentric, and more. And, any may be able to be implemented for general sketching, but, whether the solver supports them is another matter. Adding them to that could be a major effort.

I think one issue with the Sketcher is expectations. I don't think it is or was ever intended to be a general drafting tool.
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
lesthegringo
Posts: 19
Joined: Wed Nov 24, 2021 5:46 am

Re: Making lines for construction on an imported sketch

Post by lesthegringo »

drmacro wrote: Wed Nov 24, 2021 7:32 pm
lesthegringo wrote: Wed Nov 24, 2021 6:40 pm Right, thanks.... a lot more complicated than SW, QCAD, Autosketch etc.....

I may reconsider my move from SW32 bit!
You asked how to do it in FreeCAD.

Both @chrisb and I explained how it is done in two different ways.

Alas, this is FreeCAD, not SW, QCAD, Autosketch etc., unfortunately.
Indeed, I did ask how to do so in FreeCad, but please don't take it as a criticism that I find it a more complicated way of working. I do appreciate the help you are giving me.

Nonetheless I have to look at what I am doing and what I am trying to do dispassionately; the intent is to be able to create components quickly, easily and correctly. Right now with SW, despite its foibles, I can go from a blank canvas to a very complicated component in an astoundingly (for me at least!) short time. One of the reasons for that is that I am able to use the Sketch function to lay out a lot of the basic parameters and key features, and I can do that quickly due to the ability to use snaps, fillet / chamfer, arc etc tools in a fairly intuitive way. I can even work on a 2d .dfx drawing in QCAD, and import that as a starting point.

The very simple way that I can sketch out what I want I think is fundamental to my 'workflow', plus I also have to consider that these parts do not remain in the computer. I use a combination of a resin and a filament 3D printer, a CNC router, a laser engraver, a CNC desktop mill and a desktop lathe to make the parts for my flight simulator rig. Very often that also involves exporting .dxf files to CAMBAM, or to Inkscape, or .stl files to Lychee. However the number of times the 2D sketches are used for the production means that being able to produce and manipulate them is essential in the process.

My desire to learn FreeCad is not driven by the fact that SW cannot do what I want, but by the fact that I can only use it on one old PC, and if that goes down so does everything else. It also is struggling to deal with very complicated assemblies, but if I just use subassemblies it works OK. However I know that one day I will have to move on from it....

The impression I get is that Freecad can do what I want, but I would have to adopt a complete philosophy change in how I approach the workflow, which trust me at my age is no easy thing. For me, having the 2D sketching functionality and simplicity of something like QCAD or the old AutoSketch would make the whole process 100 times easier.

Just an old man's view!

Hopefully I've managed to attach a picture this time!

Cheers

Les
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