Manual:Traditional 2D drafting/it

Si può essere interessati a FreeCAD perché si ha già una certa esperienza di disegno tecnico, ad esempio con un software come AutoCAD. Si conosce già qualcosa sulla progettazione, oppure si preferisce disegnare le cose prima della loro costruzione. Per entrambi i casi, FreeCAD dispone di un ambiente di lavoro più tradizionale, con gli strumenti che si trovano nella maggior parte delle applicazioni CAD 2D: l'ambiente Draft.

L'ambiente Draft, anche se adotta metodi di lavoro ereditati dal tradizionale mondo del CAD 2D, non si limita affatto al regno 2D. Tutti i suoi strumenti lavorano in tutto lo spazio 3D e molti degli strumenti Draft, ad esempio Sposta o  Ruota, sono comunemente utilizzati in tutto FreeCAD, perché sono spesso più intuitivi che cambiare i parametri di posizionamento manualmente.

Tra gli strumenti offerti dall'ambiente Draft, si trovano gli strumenti di disegno tradizionali come Linea,  Cerchio, o  Wire (polilinea), gli strumenti di modifica come  Sposta,  Ruota o  Offset, un sistema piano di lavoro / griglia che consente di definire con precisione in quale piano si sta lavorando, e un completo sistema di aggancio che rende molto facile disegnare e posizionare gli elementi in relazione tra di loro con precisione.

Per mostrare il funzionamento e le possibilità dell'ambiente Draft, cammineremo attraverso un semplice esercizio, il cui risultato sarà questo piccolo disegno, esso mostra la planimetria di una piccola casa che contiene solo un top cucina (Un piano abbastanza assurdo, ma qui possiamo fare quello che vogliamo)?:




 * Passare nell'ambiente Draft
 * Come in tutte le applicazioni di disegno tecnico, è bene preparare il proprio ambiente in modo corretto, questo farà risparmiare un sacco di tempo. Configurare le impostazioni griglia e piano di lavoro, Testo e Dimensioni secondo le proprie preferenze nel menu Modifica -> Preferenze -> Draft. In questo esercizio, però, si procederà come se queste impostazioni delle preferenze vengano lasciate ai loro valori predefiniti.




 * L'ambiente Draft ha anche due barre degli strumenti speciali: una con le impostazioni di visualizzazione, in cui è possibile cambiare il piano di lavoro corrente, attivare o disattivare la modalità costruzione, impostare il colore della linea, il colore della faccia, lo spessore di linea e le dimensioni del testo da utilizzare per i nuovi oggetti, e un'altra con le posizioni di aggancio. Quindi, è possibile attivare disattivare la griglia e stabilire delle posizioni di Aggancio individuali:




 * Iniziare attivando la modalità costruzione che permette di disegnare alcune linee guida su cui disegnare la geometria finale.
 * Se lo si desidera, impostare il piano di lavoro in XY. Se si esegue questa operazione, il piano di lavoro non cambia, qualsiasi sia lla vista corrente. In caso contrario, il piano di lavoro si adatta automaticamente alla vista corrente, e si stare attenti ad essere nella vista dall'alto ogni volta che si vuole disegnare sul piano XY (terra).
 * Quindi, selezionare lo strumento [[Image:Draft_Rectangle.png|16px]] Rettangolo e disegnare un rettangolo, a partire dal punto (0,0,0), di 2 metri per 2 metri (lasciando Z a zero). Notare che la maggior parte dei comandi di Draft possono essere eseguiti completamente dalla tastiera, senza toccare il mouse, usando le loro due lettere di scelta rapida. Questo primo rettangolo di 2x2m può essere eseguito da tastiera con: re 0 Enter 0 Enter 0 Enter 2m Enter 2m Enter 0 Enter.
 * Duplicare il rettangolo distanziato di 15 centimetri all'interno, utilizzando lo strumento [[Image:Draft_Offset.png|16px]] Offset, attivando la sua modalità Copia, e assegnando una distanza di 15 cm:




 * We can then draw a couple of vertical lines to define where our doors and windows will be placed, using the [[Image:Draft_Line.png|16px]] Line tool. The crossing of these lines with our two rectangles will give us useful intersections to snap our walls to. Draw the first line from point (15cm, 1m, 0) to point (15cm, 3m, 0).
 * Duplicate that line 5 times, using the [[Image:Draft_Move.png|16px]] Move tool with Copy mode turned on. Turn also the Relative mode on, which will allow us to define movements in relative distances, which is eaier than calculate the exact position of each line. Give each new copy any start point, you can leave it at (0,0,0) for example, and the following relative endpoints:
 * line001: x: 10cm
 * line002: x: 120cm
 * line003: x: -55cm, y: -2m
 * line004: x: 80cm
 * line005: x: 15cm




 * That is all we need now, so we can switch construction mode off. Check that all the construction geometry has been placed into a "Construction" group, which makes it easy to hide it all at once or even delete it completely later on.
 * Now let's draw our two wall pieces using the [[Image:Draft_Wire.png|16px]] Wire tool. Make sure the [[Image:Snap_Intersection.png|16px]] intersection snap is turned on, as we will need to snap to the intersections of our lines and rectangles. Draw two wires as follow, by clicking all the points of their contours. To close them, either click onthe first point again, or press the Close button:




 * We can change their default grey color to a nice hatch pattern, by selecting both walls, then setting their Pattern property to Simple, and their Pattern size to your liking, for example 0.005.




 * We can now hide the construction geometry by right-clicking the Construction group and choose Hide Selection.
 * Let's now draw the windows and doors. Make sure the [[Image:Snap_Midpoint.png|16px]] midpoint snap is turned on, and draw six lines as follow:




 * We will now change the door line to create an opened door symbol. Start by rotating the line using the [[Image:Draft_Rotate.png|16px]] Rotate tool. Click the enpoint of the line as rotation center, give it a start angle of 0, and an end angle of -90.
 * Then create the opening arc with the [[Image:Draft_Arc.png|16px]] Arc tool. Pick the same point as the rotation center we used in the previous step as center, click the other point of the line to give the radius, then the start and end points as follow:




 * We can now start placing some furniture. To begin with, let's place a counter by drawing a rectangle from the upper left inner corner, and giving it a width of 170cm and a height of -60cm. In the image below, the Transparency property of the rectangle is set to 80%, to give it a nice furniture look.
 * Then let's add a sink and a cooktop. Drawing these kinds of symbols by hand can be very tedious, and they are usually easy to find on the internet, for example on http://www.cad-blocks.net . In the Downloads section below, for convenience, we separated a sink and a cooktop from this site, and saved them as DXF files.You can download these two files by visiting the links below, and right-clicking the Raw button, then choosing save as.
 * Inserting a DXF file into an opened FreeCAD document can be done either by choosing the File -> Import menu option, or by dragging and dropping the DXF file from your file explorer into the FreeCAD window. The contents of the DXF files might not appear right on the center of your current view, depending on where they were in the DXF file. You can use menu View -> Standard views -> Fit all to zoom out and find the imported objects. Insert the two DXF files, and move them to a suitable location on the tabletop:




 * We can now place a couple of dimensions using the [[Image:Draft_Dimension.png|16px]] Dimension tool. Dimensions are drawn by clicking 3 points: the start point, an end point, and a third point to place the dimension line. To make horizontal or vertical dimensions, even if the two first points are not aligned, press Shift while clicking the second point.
 * You can change the position of a dimension text by double-clicking the dimension in the tree view. A control point will allow you to move the text graphically. In our exercise, the "0.15" texts have been moved away for better clarity.
 * You can change the contents of the dimension text by editing their Override property. In our example, the texts of the door and windows dimensions have been edited to indicate their heights:




 * Let's add some description texts using the [[Image:Draft_Text.png|16px]] Text tool. Click a point to position the text, then enter the lines of text, pressing Enter after each line. To finish, press Enter twice.
 * The indication lines (also called "leaders") that link the texts to the item they are describing are simply done with the Wire tool. Draw wires, starting from the text position, to the place being described. Once that is done, you can add a bullet or arrow at the end of the wires by setting their End Arrow property to True




 * Our drawing is now complete! Since there begins to be quite a number of objects there, it would be wise do some cleaning and place everything in a nice structure of groups, to make the file easier to understand to another person:




 * We can now print our work by placing it on a Drawing sheet, which we will show further in this manual, or directly export our drawing to other CAD applications, by exporting it to a DXF file. Simply select our "Floor plan" group, select menu File -> Export, and select the Autodesk DXF format. The file can then be opened in any other 2D CAD application such as LibreCAD. You might notice some differences, depending on the configurations of each application.




 * The most important thing about the Draft Workbench, however, is that the geometry you create with it can be used as a base or easily extruded into 3D objects, simply by using the [[Image:Part_Extrude.png|16px]] Part_Extrude tool from the Part Workbench, or, to stay in Draft, the [[Image:Draft_Trimex.png|16px]] Trimex (Trim/Extend/Extrude) tool, which under the hood performs a Part Extrusion, but does it "the Draft way", that is, allows you to indicate and snap the extrusion length graphically. Experiment extruding our walls as shown below.
 * By pressing the [[Image:Draft_SelectPlane.png|16px]] working plane button after selecting a face of an object, you are also able to place the working plane anywhere, and therefore draw Draft objects in different planes, for example on top of the walls. These can then be extruded to form other3D solids. Experiment setting the working plane on one of the top faces of the walls, then draw some rectangles up there.




 * All kinds of openings can also be done as easily by drawing Draft objects on the faces of walls, then extruding them, then using the boolean tools from the Part Workbench to subtract them from another solid, as we saw in the previous chapter.

Fundamentally, what the Draft Workbench does is provide graphical ways to create basic Part operations. While in Part you will usually position objects by setting their placement property by hand, in Draft you can do it on-screen. There are times when one is better, other times when the other is preferable. Don't forget, you can create custom toolars in one of these workbenches, add the tools from the other, and get the best of both worlds.

Downloads


 * The file created during this exercise: https://github.com/yorikvanhavre/FreeCAD-manual/blob/master/files/cabin.FCStd
 * The sink DXF file: https://github.com/yorikvanhavre/FreeCAD-manual/blob/master/files/sink.dxf
 * The cooktop DXF file: https://github.com/yorikvanhavre/FreeCAD-manual/blob/master/files/cooktop.dxf
 * The final DXF file produced during this exercise: https://github.com/yorikvanhavre/FreeCAD-manual/blob/master/files/cabin.dxf

Read more


 * The Draft Workbench
 * Snapping
 * The Draft working plane