Very often there is a need to build a 3D object of a certain cross-section along a complex path, such as piping, wiring, pipes, hoses of sleeves, etc. Such an object can be constructed using the EXTRUDE using the Trajectory parameter, or by using the SHIFT command on the toolbar Modeling.
First, we build a path necessarily using the POLYLINE command, the geometry can be any.
We construct a section that will be extruded, necessarily perpendicular to the trajectory, in our case it is a circle.
Select the command to EXTRUDE.
At the prompt, enter the command line » T » (for the Russian version of AutoCAD) ie squeeze the trajectory.
Frequently asked question when working in AutoCAD is the dialog boxes that suddenly cease to appear when calling commands, for example when saving a drawing or opening a new drawing, while a request for a drawing name is issued via the command line.
For the appearance of dialog boxes in AutoCAD, the FILEDIA variable responds. If its value is 1, then when calling commands that have dialog windows, they will appear, if the value is 0, then all user interaction will occur via the command line. to change the value, enter FILEDIA on the command line and set the desired value.
The building of fillets and angle mates in a flat or a 3D object in AutoCAD is done with a team MATE (_fillet). You can run the command by typing at the command prompt or by clicking on the toolbar.
After running the command, options for further actions appear:
Entering a letter:
T — cancel the command,
And it will be possible to select a polyline where you will build a fillet all corners of a given radius,
D — set radius value,
B — set the mode with or without cropping the lines that create the angle to be rounded,
H — you can round multiple corners without interrupting the command.
If the choice of the lines forming the angle, but does not have a common point of intersection to hold down the Shift key, the command will extend these lines to their intersection point.
Calculation of mass of a 3D solid
In AutoCAD, you can cut a 3D solid to produce new 3D bodies in several ways. Consider two ways.
The easiest, use the CUT command (_slice in English version). At the command prompt, type CUT, press Enter, select 3D solid, and then the command prompts you for several options for cutting the solid. You can cut a body by specifying three points (the default) by selecting a flat object, a surface, or one of the coordinate planes (XY, YZ, ZX).
Another way to create another 3D solid completely intersecting the one you want to cut. Next, using the command SUBTRACT (_subtract) cut the desired 3D body by subtracting from it another 3D body.
However, after you use the command REDTEL (_separate), to actually divide the body into several.
AutoCAD is a very versatile CAD program. In confirmation of this, let’s consider a method by which you can translate relatively simple graphics from pdf to dwg format without the use of special programs. The essence of the method is to insert the so-called «pdf Underlay»into the current AutoCAD document. Open the Insert menu, select PDF Underlay. The pdf file selection window appears, select the file and in the next window select the desired page, the insertion point in the document and the scale if necessary.
If the graphics in the PDF vector after inserting into the AutoCAD document to it can be bound by object binding and» outline » the graphics pdf standard means AutoCAD such as polyline, circle, spline, etc.
Several variables are «in charge» of binding to the substrate graph: DWFOSNAP, PDFOSNAP, DGNOSNAP, their values must be equal to «1» for the binding to work.
To calculate the mass, volume, center of mass of a volumetric body in AutoCAD, there is a corresponding command button to call it is on the Details panel.
Also call the command with its command-line MASS-HAR or _MASSPROP and press Enter.
After you run the command, you must select a volumetric body, then a window with the characteristics of the 3D body will appear.
The first line is called Mass, but in fact it is the Volume of the selected body in mm3.
To obtain body weight, it is necessary to make some calculations, namely, multiply the value In the mass or Volume column by the density of the materials that corresponds to this solid.
To simplify and speed up this procedure, it is easier to use the appropriate application for calculating the mass of 3D body in AutoCAD.
In AutoCAD 2015, the function of pre-selection of objects when you hover the mouse pointer over them, this function is not always and not for all is convenient and useful. For disabling pre-selection of objects meets the variable
SELECTIONPREVIEW. when calling it from the command line and setting the value to 0, the function of preliminary selection of objects will be disabled .
Quite often there is a need to reduce the size of the AutoCAD DWG file, except for the methods already described in the article, we will consider two more. In AutoCAD, there is a command that allows you to delete Unused blocks in the current file, fonts, layers, etc., which also increase the file size. To call this command, select the File menu, then the Utilities item, the Clear command, in the command window click the «Delete All» button.
Blocks can be used to reduce the size of a DWG file with a large 3D assembly containing duplicate objects (_block command in the Russian version). We place one instance of an object or a group of objects in a block, and use the already created block as the remaining instances. when inserting the next block instance into a file, AutoCAD inserts only a link to it, which significantly reduces the file size .