We develop a belt drive in nanoCAD 21 (part 3 of 3)

Build Using 3D Constraint Toolkit

Assembling a finished product involves more than just combining parts with each other. In the nanoCAD platform, an assembly is a combination of parts using 3D constraints. These constraints allow you to link items together so that the assembly becomes one piece while still being a set of parts. There are five types of 3D constraints:

3D insert

inserting one 3D object into another, or inserting to ensure the alignment of two 3D objects. Works with radial elements;

3D registration

combining the geometry of one 3D object with another;

angular 3D constraint

setting the angle between two 3D objects;

3D touch

allows you to create more complex tangencies of surfaces than the 3D alignment constraint, for example, such as: cylinder to plane, cylinder to cylinder, cone to plane, etc.;

3D symmetry

allows you to align 3D solid elements symmetrically about the selected plane.

Before assembling the drive, it is necessary to place the parts in one drawing, where the assembly will be carried out. It is not necessary to do this right away, we will add the necessary details as needed.

We carry out the assembly from the stove. To begin with, we fix it in the model using the Fix command, by opening the context menu of the slab in the construction history (Fig. 21). In this case, the part icon will be supplemented with an anchor icon: … Thanks to this operation, the plate will remain stationary during the assembly process. If necessary, you can undo the fixing of the part at any time by using the Unfix command in the same context menu. …

Fig.  21. Fixing a part in the construction history window
Fig. 21. Fixing a part in the construction history window

Add a glass of one of the shafts and fasteners: washers and bolts. Since the glass is made in a separate file, it must be inserted into the current drawing. I already started out of habit to open a file with a glass in order to copy it through the clipboard, but I remembered that the developer casually mentioned the new possibility of working with links. I close the file with the part, insert it as a regular external link – and the part I need appears in the construction history window (Fig. 22). This tool opens up completely new possibilities for the design of complex products consisting of multiple assemblies, subassemblies, etc. When you insert a component with a link, all changes in the part file also occur in the assembly file (unless, of course, the link is broken). This is definitely a big advantage over simple copying. But let’s postpone a detailed conversation on this topic until another occasion and continue with the assembly.

Fig.  22. Adding parts to an assembly as xrefs
Fig. 22. Adding parts to an assembly as xrefs

Add fasteners from the base of elements. To do this, switch to the database tab and go to the Fastening parts → General mechanical engineering → Washers → Spring washers section and to the Fastening parts → General mechanical engineering → Bolts → Hexagon head section to accommodate the bolts (Fig. 23).

Fig.  23. Window of the base of elements
Fig. 23. Window of the base of elements

Before selecting the required normative document for a part, make sure that the Use 3D model button is pressed when inserting standard parts, since the base contains both 3D and 2D representations of parts. Next, we select the normative document, place the element in space and select the element parameters in the parameters window (Fig. 24).

Fig.  24. Placing a standard element
Fig. 24. Placing a standard element

Place the bolt in the same way and copy it according to the number of sets (four) – fig. 25. After placing all the necessary elements in the model, you can start assembling.

Fig.  25. Plate, glass and fasteners are ready for assembly
Fig. 25. Plate, glass and fasteners are ready for assembly

We combine the plate and glass using the 3D insert constraint. Sequentially point to the aligned edges of one part and the second (Fig. 26).

Fig.  26. When 3D-inserting, specify the aligned edges of the parts
Fig. 26. When 3D-inserting, specify the aligned edges of the parts

As a result, both parts are aligned coaxially (Fig. 27). In this case, the initial position of the parts in space does not matter, as can be seen from the example of fasteners.

Fig.  27. Combined details
Fig. 27. Combined details

Sometimes dependency alone may not be enough to reliably tie parts together. In our case, for example, the glass was inserted into the hole in the plate, the holes for the fasteners were visually aligned as well. But if you try to rotate the plate in space around the axis of the glass, the holes for the fasteners may “run away” (Fig. 28).

Fig.  28. Loss of alignment of the holes in the plate and the nozzle as a result of turning one of the parts
Fig. 28. Loss of alignment of the holes in the plate and the nozzle as a result of turning one of the parts

To avoid this, you will need to impose one more dependency: 3D alignment (Fig. 29). It is enough to align one of the holes, and the parts will reliably connect. Now, no matter how we try to move or rotate one of the parts, the second will follow it.

Fig.  29. Constraining 3D registration
Fig. 29. Constraint 3D registration

Install the fasteners with a 3D insert in the following sequence: the washer to the hole in the plate, the bolt to the washer (Fig. 30).

Fig.  30. Specify the face for the 3D-insert of the bolt
Fig. 30. Specify the face for the 3D-insert of the bolt

As a result, we get an assembly of two parts and fasteners (Fig. 31). In the 3D Draw History window, each part is displayed as a separate position, and when a part is selected, it will be highlighted in the model. The reverse link also works.

Fig.  31. The glass is connected to the stove
Fig. 31. The glass is connected to the stove

Further assembly of the drive is carried out in the same way, part by part.

conclusions

In this article, I tried to present the sequence of creating a prefabricated product. Of course, the format of the article does not allow describing all the nuances of the workflow. It did not cover cross parameterization of two or more assembly elements, the creation of revolved shapes, chamfers, fillets, threads, and much more that is already in the program. In doing so, I focused on creating sheetable 3D solids. Could I create sheet metal in version 20 with the tools it contains? Of course he could. I would have spent much more time on work, but I did. But I would definitely not be able to get a scan from a sheet 3D body, which is simply necessary for the manufacture of a part. At the same time, in nanoCAD 21, I received a ready-made scan of the main fan drive plate with all the holes in three mouse clicks (Fig. 32).

Fig.  32. Obtaining a flat pattern of a sheet body
Fig. 32. Obtaining a flat pattern of a sheet body

In the example presented, I have used only three commands for working with sheet bodies out of seventeen possible. I am sure that upon further study of the 21st version of nanoCAD with the “Mechanics” module, I will meet with other equally useful innovations.

Sergey Stromkov
engineer of the first category
Arksoft company
arcsoft.ru

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