Calculation info
Purposes and multipliers
Purpose affects material usage, design effort, and failure risk via a multiplier:
- general: 1.0
- prototype: 0.8
- functional: 1.2
- critical: 2.5
Infill multiplier represents the expected density of the printed object compared to its bounding box volume. It does not only represent infill but also occupancy of the bounding box volume. Recommended values:
- 0.10 - Default value
- 0.06 - Very hollow object (e.g., box)
- 0.16 - Moderately filled object (e.g., functional part)
- 0.26 - Mostly solid object (e.g., mechanical part)
Cost estimate model
Formulas mirror the implementation of cost estimate calcuation:
- Size conversion (cm³):
size_cm3 = (x_dim * y_dim * z_dim) / 1000 - Printing time (hours):
printing_time_hours = (size * infill_multiplier * complexity_multiplier) / flow_rate - Material cost (EUR):
material_cost = size * material_density * material_cost_per_gram * infill_multiplier * complexity_multiplier * PURPOSES[purpose]Assuming that the more advanced items will require more specific and costly materials. - Electricity cost (EUR):
electricity_cost = printing_time_hours * (printer_wattage / 1000) * electricity_cost_per_kwh - Depreciation cost (EUR):
depreciation_cost = (cost_of_3d_printer / printer_lifespan_hours) * printing_time_hoursIncludes also maintenance cost - Failure rate:
failure_rate = (0.01 if ups_connected else 0.05) * complexity_multiplier * PURPOSES[purpose]Assuming that the presence of a UPS reduces failure rate due to stable power supply. Also more complex items have higher failure rates due to QC requirements. - Design cost (EUR):
design_cost = 0.0 if design_done else (design_cost * complexity_multiplier * PURPOSES[purpose])More complex items will require more design time and testing.
Per-item manufacturing price and totals:
- Manufacturing cost estimate:
manufacturing_price_per_item = (material_cost + electricity_cost + depreciation_cost) * (1 + failure_rate) - Total cost estimate of manufacturing all item including design cost:
total_price = manufacturing_price_per_item * quantity + design_cost - Cost estimate per item including design cost:
price_per_item = total_price / quantity