In this paper, the authors present a study, of the situation in which the Inventor software is used, regarding the possibility of automating the obtaining offree contours after which the desired ...cutouts can be made in the decorative elements. The authors had realized a study concerning the possibility to reproduce contoms that were drawn using the free hand, in the Inventor software, to use tlris computer program for the activity of design of some decorative and non-decorative elements for the garden. The RCD calculation program allows the automatic collection of the coordinates of the points defining a spline curve by selecting it with the cursor and saving them in a CSV file. The CSV file allows automatic data export to the Autodesk Inventor software 3.
In turn, these two stages can be divided into several steps as follows: - design stage (office): * determination in double orthogonal, in the draught, of the polygon or polygons of intersection, ...depending on the type of intersection obtained; * positioning on the polyhedron or polyhedra that will be unfolded of the points that determine the vertices of the polygon or polygons of intersection; * carrying out the deployment for one or both polyhedra; * determination, according to the horizontal and vertical projections of the vertices of intersecting polygon or polygons, of the positions of these points on the unfolding of the polyhedron or polyhedra. - execution stage (construction site): * marking on the physical body, depending on the data obtained from the unfolding, of the points that will determine the vertices of the polygon or polygons of section; * making the cut-out or cut-outs both according to the positions of the points that determine the vertices of the section polygon or polygons and according to the three-dimensional model of the joint. To be able to use the advantages offered by computer-assisted graphics, the authors proposed that the realization of the polyhedra under study (Figure 3) 3 be made in a volume model 1. DISCUSSIONS AND CONCLUSIONS Following the study, the authors came to the following conclusions: - regardless of the number of sides, polyhedra's type (prism or pyramid) and their number, the presented steps that allow the determination of the unfolding of the polyhedron or polyhedra but also of the intersection polygons are identical; - the reasoning is similar regardless of the positions of the bases: * both located in the horizontal projection plane H; * both located in the vertical projection plane V; * both located in general position plane P; * one base located in one type of plan and the other base in another type of plan; - compared to the classical variant, the duration of determining the unfolding of the polyhedra but also of the intersection polygons is much shorter; - the working method proposed by the authors can be used only by people who have in-depth knowledge of both Descriptive Geometry and 3D computer modelling.
...the looked-for solution should allow visualization of how the shape of the curve changes depending on the sizes of the analysed surfaces and the angle between the axes of the two surfaces. The ...dimensions of the 3D bodies can be introduced with precise values but these dimensions are only on the OX. ...to change the diameter of a circle located in the XOY plane, the dimensions that define the circle at the base of the cylinder, along the axes OX and OY must have equal sizes. 20 mm in the example shown in Figure 3. ...the software draws a curve inscribed in a rectangle. The user controls the dimensions of this rectangle. ...another main drawback results, namely, when the size of one side changes, the calculation is made starting from the other side and not from the centre of the rectangle. ...once two cylinders with intersecting axes have been built, when the circle's diameter at the cylinder's base changes, the position of the axis of the respective cylinder changes in space, which makes the cylinders no longer have intersecting axes. ...after each change of the circle's diameter at the base of the cylinder, it is necessary to reposition it.
...the authors present the solutions offered for this problem by the computer programs when 3D model is used. ...they agreed that it necessary to analyse which tools provide software such Aut°CAD or ...Inventor to solve this problem when a part is designed, from the start, using 3D model. First one is based on the method of substituting planes of projection, and the second is based on the folding method of the planes on a level plane 1, 2, 3. The new projection axis (O2X2) is choose in such way in that, in the new projection system O2X2ViHi, the intersection line is a vertical line. ...the projection line O2X2 is perpendicular on the (d'i) projection, and the intersection line (D) has, in the projection system (O2X2)ViHi, the projections (d'i) and (di).
Key words: technical drawing, layouts, scales, format, dimensioning, CAD 1.INTRODUCTION From the experience gained, the authors know that the steps that put students, but also users with little ...experience in using Aut°CAD, in the stages of dimensioning and formatting some representations, are related to: - choosing the dimensions of printing layout of the sheets; - setting the units of measure in which they are displayed the dimensions on printed sheet: o meter; o centimeter; o millimeter. - setting values for some dimension variable 2: o length (length of the extension line); o extend beyond dim lines and offset from origin (settings for establishment of the start and ending points of the extension lines); o arrow size (the delimiters' size of the dimension lines); o text height (the size of the dimension text); o offset from dim line (the distance from the dimension text to the dimension line); o precision (the unit format and his precision); o scale factor (the scale factor for the dimension text). Taking into account the fact that for getting the optimal version of the drawing there are many variables that influence each other, the authors have designed a computer program which according to a series of elements specified by the user: - sets the dimensioning variables; - represents the title block and the format of the drawing to the scale chosen by the user and to the measure unit desired by him. 2.MATERIAL AND METHOD At the start, the authors focused on the units of measure analysis, used by the students for draw of the current level plane of a residential building. ...if one user chose the meter (1 m) as measure unit for draw the drawing and another user chose the centimeter (1 cm), the values of the dimensioning variables, of the title block dimensions and drawing format dimensions differs from one user to another because these chose different units of measure for making the drawings. At the end of the test: - 23 students (76,67%) have correctly choose the drawing format and the representation scale without any guidance and specified the fact that the computer program is very useful; - 7 students (23,33%) have correctly choose the representation scale but the adopted drawing format and the title block for one or both graphical representations were bigger or smaller than optimal, in which case they received guidance; - from those 23 students that have correctly choose the drawing format and the representation scale, 6 (26,09%) they wanted to know if: o two or more representation scale can be set on the same drawing format; o multiple dimension styles can be automatically set in which some variables have same values and other have different values with the aim: * dimensioning of the representations on the same drawing to different representation scales; * the use of several types of delimiters for the dimension lines in the case of little distances or for leaders; * the use multiple heights for the dimension text; * the use many more precision modes to displaying the quotes; * the use of multiple scaling factors for the values of the quotes.
BUILDING A PERGOLA IN CAD SYSTEMS Pruna, Liviu; Slonovschi, Andrei
Journal of Industrial Design and Engineering Graphics,
05/2017, Letnik:
12, Številka:
1
Journal Article
Odprti dostop
In this paper the authors present a study and the conclusions they reached, regarding the possibility to automatically representing a pergola, when a CAD system is used. Also, a computer program, ...made by the authors is presented. This software was named Pergola and it offer the opportunity to sketch a pergola which cover a rectangular or circular area, when using the AutoCAD Architecture or AutoCAD computer program.
For helping the user to pursue the software logic, to understand the projections which will be represented (a, a', a", ax, ay, ay1 and az), their names, the order and their position in relation with ...the origin O, the computer program specifies to the user these data by using a series of dialog boxes. ...after which the values of the abscissa, distance and quota are specified, the computer program displays the dialog box from Fig. 3 in which it specify that: * the projection that will be specified will be ax; * the ax projection is situated in the left side of the origin (because the given value, by the user, for abscissa is positive); Fig. 3 The message displayed by the computer program after the values for abscissa, distance and quota were specified. By pressing the Ok button the computer program displays the place of the horizontal projection a, of the point A (a, a', a") and at the dialog Please select the point for annotation the user specifies the location of the a notation then, the software writes this text (Figure 9). ...the computer program, through the message presented in Figure 11, announce the user that to the end of the line of recall, previously represented, will draw the vertical projection a' which is situated above the X axis (on the negative part of the Y axis) because the value of the quota specified by the user is positive. By pressing the Ok button the computer program displays...
The paper presents a set of equations that stands to the basis of a computer program and to the software themselves, that offers to the user the possibility to automatic draw the arcs used to ...approximate the representation of a chamfer hexagonal prism. Also, the authors present the way to use software that generates the arcs that approximate hyperbolas resulting on a chamfered hexagonal prism.
The paper presents a set of equations that stands to the basis of a computer program and to the software themselves, that offers to the user the possibility to automatic draw the arcs used to ...approximate the representation of a chamfer hexagonal prism. Also, the authors present the way to use software that generates the arcs that approximate hyperbolas resulting on a chamfered hexagonal prism.
The technical drawing is one of the fundamental disciplines that helps to the forming of the students because, it offers all the rules through that the engineering drawings are correctly achieved. ...Also, the knowledge acquired to this discipline, during the years of study, help the specialists, from the domain of the technical sciences, to understand the drawings, thus giving them the possibility to obtain the elements represented in drawings. Starting from these data the authors have proposed and have accomplished a statistical analysis through which to observe, on a sample of students, the steps that raise the most difficulties in the activity of achieving of a technical drawing because this activity, in addition, requires understanding of the elements that must represented.
