# Automated Design and Parametric Modeling of Excavator Buckets
## 2 Literature Review
### Bucket Classification  
Depending on the operational weight of the excavator, a classification of the buckets by classes was made (Table 1). Each bucket, depending on its class, differs in shape, dimensions, length, volume, and other specific indicators [1; 2; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23].  
Excavator buckets are characterized by the following features, which 3D models must also possess: bucket length; attachment for establishing the arm of the excavator; and type, size, and number of used teeth.  
Depending on the class, the length of the buckets is from 600 mm to 1500 mm and, for larger classes, it reaches up to 2000 mm. The excavator arm is attached to the bucket attachment holes using pins. The bucket attachment is different for all the models of excavators. The type and size of the teeth depends on the class of the bucket and the customer requirements, and their number is determined by the length of the bucket.  
It should be noted that it is possible to manufacture special bucket designs [1; 2; 13]. For this purpose, standard designs are used, to which the necessary changes are made. This happens often, since sometimes buckets are used under specific operating conditions that require specialized designs, which are different from standard models. Special bucket designs are shown in Figure 1. These are, for example, buckets with a length of 400 mm and 500 mm, buckets with specialized attachments, for mounting the quick-change devices (Quick Couplers), buckets with holes on the side surfaces, buckets without teeth, etc.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Excavator Operating Weight, t** & **5** & **9** & **14** & **17** & **23** & **27** & **31** & **40** & **55** & **70** & **95** & **130** \\
**8** & **13** & **16** & **22** & **26** & **30** & **38** & **50** & **65** & **90** & **120** & **150** \\ \hline Bucket class & A & B & C & D & E & F & G & H & J & K & L & M \\ \hline \hline \end{tabular}
\end{table}
Table 1: Classification of buckets, depending on the operating weight of the excavator.  
Figure 1: Special bucket designs class D: (**a**) 400 mm; (**b**) 500 mm; (**c**) 1000 mm—QC (Quick Coupler); (**d**) 1000 mm—QC1 (Quick Coupler 1); (**e**) 1000 mm—with holes; (**f**) 1000 mm—without teeth.  
According to the classification presented in Table 1, multiple 3D models need to be developed as follows for:  
* Each bucket length for each class;
* All types of bucket attachments used by various excavators;
* Each different tooth model.  
In conclusion, it can be said that, with so many different versions and variations of bucket designs, the task of designing them becomes very difficult, both in terms of the huge amount of work involved in the design and in terms of the complexity of the work and control of the entire work process.  
A certain product can be designed by applying two main methods--traditional modeling or parametric modeling. Both approaches are applied in practice. Depending on the products being developed, the method to be used is also chosen.  
In addition, the development of 3D models must be consistent with the technology for manufacturing the buckets, as well as with the possibility of using the models from the PDM and ERP system.