ReadMe:

Cost tool for the publication with the title: Methodology for Cost Estimation Using Characteristic Factors in Additive Manufacturing

Authors:  *K. Asami1, 2, D. Herzog1, 3, T. Deutschmann1, T. Röver1, 2, I. Kelbassa1, 3, C. Emmelmann1, 2 (1.Hamburg University of Technology, Germany, 2.Institute of Laser and Systems Technology, Germany, 3.Institute for Industrialization of Smart Materials, Germany) 

Description:

The cost tool for Additive Manufacturing (AM) processes was developed to provide a simplified estimate of the manufacturing costs of additively manufactured components compared to traditional manufacturing methods such as casting or milling. Since the costs for AM processes in series production, especially for medium and large quantities, are often higher than for conventional processes, the tool offers a method to realistically compare these costs.

The tool is based on a model that estimates the manufacturing costs based on the component volume. First, the volume of the conventional part design is used as a starting point to approximate the price of the part for AM processes such as powder bed fusion and sinter-based methods. Since these costs are usually higher, the tool translates these higher costs into a weight saving requirement that must be met to achieve the cost of the conventional process.

The tool then evaluates this requirement in terms of the typical weight-saving potential of the respective AM technologies in order to predict the economic feasibility of additive manufacturing for the specific component.

The application consists of four sheet: Input-Output, Process Parameter, Machines and Specific Parameter. It can estimate the cost dependent on the provided information. The application is implemented in excel and the sheets Process Parameter and specific Parameters are completely protected.

Simplifications for the estimation: 

PBF-LB/M: 

Influencing factors: Print time is the sum of exposure time and recoating time. The recoating time depends on the number of layers, i.e. build height divided by layer thickness, independent of the number of parts fitting onto the build plate. The exposure time is mainly dependent on the volume of the printed structure (parts and supports).

Simplification: Print time is estimated from the part volume multiplied by a theoretical build rate per machine and material, neglecting recoating time.

MEX/M: 

Influencing factors: The printing time is dependent on the process parameters such as the layer height and the printing velocity. 

Simplification: Only one process parameter set up is assumed.

Binderjetting: 

Influencing factors: De powdering is a required step for geometries with channels or inner structure after the print job depending on the part complexity.

Simplification: The time for the de powdering is only estimated in the se up time independent of the part complexity.


For all technologies:

1)

Influencing factors: The setup time occurs with each new batch. During this time, labor is utilized.

Simplification: The set-up time is reduced to a fixed value for each machine.

2)

Influencing factors: The material loss is all the material that is needed but is not in the finished component.

Simplification: Material loss is estimated solely by considering shrinkage with a fixed percentage value. Other losses, such as those from support structures, are neglected.

3)

Influencing factors: For machine costs, the batch size is essential. The batch size is influenced by the geometry of the components, the type of manufacturing or processing, and the build volume of the manufacturing machine.

Simplification: To determine the batch size, the length and width of a rectangle assumed around the base area of the component are used as additional input parameters. The calculation is then made to see how many times this rectangle fits into the base area of the respective machine. If stacking is possible, the calculation is similarly performed in three-dimensional space.

4)

Influencing factors: The post-processing costs include, for example, the removal of support structures or the post-processing of functional surfaces.

Simplification: The post-processing costs are estimated on the basis of a classification of the work involved. The classification is based on a scale of 0-3.

5.)

Influencing factors: Overhead costs include all cost items whose significance has proven to be minor in the course of creating the calculation. It also includes costs that cannot be attributed to a single cost carrier.

Simplification: An upper and lower limit for the cost per batch is established for each machine. From these, an average value and a range for the overhead costs are calculated.



Cost tool: 

Input-Output:

On this page the Input section allow to provide the information of the component dimension, volume, the selected material, the manufacturing quantity, the post-processing factor and the costs of the conventional manufacturing process.
The machine section allow to select the specific machines for the manufacturing technologies: filament-based material extrusion of metal (MEX/M), the powder bed fusion laser based (PBF-LB/M), the binderjetting (BJT/M) and the metal injection molding (MIM).
The Output section provide the specific costs in € of each process step, the total costs in € of the technology, the necessary weight saving in percent of the component to achieve the same costs as in the conventional manufacturing method and a comment section provide an information if the process is suitable for the entered component characteristics. 

Process Parameter: 

In the Metals section it is possible to enter the material costs for the specific materials and also to change the name of the material. It is also possible to change the Binder costs. The print velocity is a value for the productivity of the technology and can also be changed.

Machines:

The machines can be changed and added on this page. The necessary information are required for each process step. If the technology has not the process step nothing has to be added in this case. Afterwards the machine with each process stepp will appear on the Input-Output page.

specific Parameter: 

No values have to be changed to receive a cost estimation. 



For further information please contact: karim.asami@tuhh.de