## 5 Cost Evaluation
### Economic Evaluation of Composite Blade Manufacturing  
The costs related to the physical manufacture of the prototype of the anti-torque blade can be separated into two distinct categories: costs related to the materials used and costs related to the labour involved in its manufacture. Thus, the costs but also the type of materials involved in the manufacture of the blade are centralised in Table 5, which are necessary to manufacture the composite blade. It can be observed that the total amount of materials involved in making the blade is around EUR 680.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Manufacturing Process** & **Mould Cost** & **Mould Manufacturing Time** \\  & **[EUR]** & **[h]** \\ \hline
3D printing & 1027.3 & 540 \\ CNC machining & 3335.3 & 120 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Comparison of cost and manufacturing time of different processes for manufacturing moulds.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**No.** & **Material** & **Unit** & **Quantity** & **Unit Price** & **Price** \\  & & **[EUR]** & **[EUR]** & **[EUR]** \\ \hline
1. & Carbon fibre & [m\({}^{2}\)] & 7 & 42.6 & 298.2 \\
2. & Red carbon fibre & [m\({}^{2}\)] & 2 & 48.6 & 97.2 \\
3. & Fibreglass tape 50 mm & [mL] & 62 & 0.3 & 22.5 \\
4. & Kevlar fibre & [m\({}^{2}\)] & 2 & 46 & 92 \\
5. & Epoxy resin and hardener & [L] & 1 & 37.4 & 37.4 \\
6. & Degreaser & [L] & 2 & 6.4 & 12.8 \\
7. & Protective gloves & [pcs] & 1 & 15 & 15 \\
8. & Wax & [pcs] & 1 & 11.2 & 11.2 \\
9. & Brush 0.5\({}^{\prime\prime}\) & [pcs] & 5 & 0.8 & 4 \\
10. & Brush 1\({}^{\prime\prime}\) & [ppc] & 5 & 0.9 & 4.5 \\
11. & Brush 2\({}^{\prime\prime}\) & [pcs] & 5 & 1.2 & 6 \\
12. & Protection foil & [pcs] & 1 & 5 & 5 \\
13. & Metal bushing ID20 & [pcs] & 2 & 5 & 10 \\
14. & 3D-printed core & [pcs] & 1 & 20 & 20 \\
15. & Carbon rods & [pcs] & 2 & 3.6 & 7.2 \\
16. & Paper tape & [pcs] & 3 & 1.2 & 3.6 \\
17. & Spray 400 mL RAL 6002 & [pcs] & 2 & 9.4 & 18.8 \\
18. & Spray 400 mL lac 1k & [pcs] & 2 & 7.6 & 15.2 \\  & & & & & 680.6 \\ \hline \hline \end{tabular}
\end{table}
Table 5: The type and quantity of materials used in the manufacture of composite blades.  
The cost of labour was calculated at 10 EUR/hour, the same as for the labour involved in the execution of the mould. The main operations used in the manufacture of the anti-torque blade are as follows: mould preparation 2 h; composite layer design 2 h; manual cutting of layers 10 h; preparation of workspace 2 h; preparation of materials needed in the lamination process 1 h; lamination of the anti-torque blade 9 h (3 operators \(\times\) 3 h); blade demoulding 3 h; blade adjustment after demoulding 2 h; lamination of final carbon and Kevlar layers 8 h; blade adjustment 1 h; preparation for painting the blade 2 h; painting the blade 1 h; and varnishing the blade 1 h. These cumulative activities total 44 labour hours, which means that the total labour costs of the composite blade were EUR 440. Adding the material costs to the labour costs results in a production cost of an anti-torque composite blade of EUR 1120.  
In Table 6, the total production costs of the composite blade are summarised, which include the costs of preparing and manufacturing the mould and the costs of manufacturing the composite blade for the two following scenarios: the CNC machining mould and the 3D-printed mould.