Introduction[edit | edit source]
MOST performs tests to measure the energy required to produce a 3D print in units of kWh/kg, termed specific energy. This data is useful when performing economic and environmental life-cycle analysis of printed parts. See for example:
- Environmental life cycle analysis of distributed 3-D printing and conventional manufacturing of polymer products
- Environmental impacts of distributed manufacturing from 3-D printing of polymer components and products
- Life-cycle economic analysis of distributed manufacturing with open-source 3-D printers
Following is the protocol used for collecting this data.
Equipment[edit | edit source]
- RepRap 3D printer and host computer
- kW-hr monitor such as the commercial Kill-A-Watt power monitor (The precision of the Kill-A-Watt is around 0.01 kWh)
- Timepiece if printer host does not display print duration
Method[edit | edit source]
- Plug the power monitor into an outlet and plug the printer's power supply into it.
- Chose an open source digital design that will weigh more than 50g when printed. (Small prints can consume less than 0.01kWh.)
- Ensure heaters (hot end, heated bed, etc.) are at room temperature.
- After slicing the model and just before printing it, record:
- print description
- nozzle diameter (mm)
- print T (C)
- heated bed T (C)
- print speed (mm/s)
- starting kWh
- Print the model.
- When the print is complete, record:
- ending kWh
- actual print time
- weight of the print (kg) see; Digital mass protocol:MOST
Reporting[edit | edit source]
- Calculate the energy consumed by subtracting the starting kWh reading from the ending kWh reading.
- Group the data by print speed and nozzle diameter.
- Create a scatter plot with power consumption (kWh) on the ordinate and printed part weight (kg) on the abscissa. A data series should be created for each group of print speed and nozzle diameter. For example, if one series of prints was performed at 60 mm/s with a 0.5mm nozzle and another at 30mm/s with a 0.5mm nozzle, two data series would be required.
- Add a trendlines to the plot and display the equations.
- Record the slope of the trendline(s) as the specific energy and the intercepts as warming and idle energy.
