Before you choose
- Use explicit assumptions, including failed attempts.
- Separate a workshop estimate from a supplier quotation.
- Model powder recovery and batch processes separately when needed.
Choose the comparison unit
For a print farm, an accepted part can be a more useful unit than a spool or bottle. Define the geometry, process, production quantity and acceptance criteria. Include supports or other material consumed by an attempt rather than using the finished-part mass alone.
Show the costs that change the result
Material cost, machine time and post-processing can all contribute. Assign a machine-hour cost appropriate to the workshop and allocate batch work consistently. Cleaning, curing, support removal, inspection and rework should be included where they apply.
Account for yield explicitly
In the simple model below, expected cost per accepted part equals cost per attempt divided by the fraction of attempts accepted. The yield is an editable assumption, not a prediction of a grade’s reliability. If a defect affects a whole batch together, use a model that captures that relationship.
Keep the estimate’s boundaries visible
The calculator is a one-part-equivalent screening model for material consumption and allocated machine/finishing costs. Freight, taxes, setup, development, tooling and overhead not entered are excluded. SLS build charge, refresh and recovery need an additional material balance; this tool does not calculate those flows.
| Input | Use the same basis for both materials |
|---|---|
| Material consumed | Part plus supports or other consumed mass per attempt |
| Machine time | Time allocated to one attempted part |
| Finishing | Cost allocated to that attempt |
| Yield | Accepted attempts divided by total attempts |
| Commercial costs | Add freight, fees or setup outside this simple model |
A worked comparison with visible assumptions
Take a fictional 140 g total consumed mass, 2.5 allocated machine hours at $3/hour and $2 finishing per attempt. At $30/kg, an attempt costs $13.70. With an assumed 80% accepted-attempt rate, the expected accepted-part cost is about $17.13.
Change material price to $45/kg and assume a 95% accepted-attempt rate. Attempt cost becomes $15.80 and the accepted-part estimate becomes about $16.63. The apparent advantage comes from the assumed yield change. This example is not evidence that buying a higher-priced grade improves yield.
If both instead achieve 95%, the $30/kg case is about $14.42 per accepted part. Measure the process and keep the assumptions visible before drawing a buying conclusion. All amounts here are illustrative workshop inputs, not supplier prices or forecasts.
| Illustrative case | Material / attempt | Total / attempt | Assumed yield | Cost / accepted |
|---|---|---|---|---|
| A: $30/kg | $4.20 | $13.70 | 80% | $17.13 |
| B: $45/kg | $6.30 | $15.80 | 95% | $16.63 |
| A with the same yield as B | $4.20 | $13.70 | 95% | $14.42 |
EDITABLE PLANNING EXAMPLE
What is the cost of one accepted part?
Defaults are illustrative assumptions, not JoySpool prices. Enter costs on a one-attempt, one-part-equivalent basis. Freight, taxes and costs not entered are excluded.
- Material / attempt
- $4.20
- Machine / attempt
- $7.50
- Finishing / attempt
- $2.00
- Total / attempt
- $13.70
Use nonnegative inputs and an accepted-attempt percentage greater than 0 and no more than 100.
Cost / accepted part = ((part g + support g) ÷ 1,000 × price/kg + hours × hourly cost + finishing) ÷ (accepted % ÷ 100).
Screening model only. Powder recovery, build charge, multi-part batch dependencies and differing failure stages require a fuller process model.
Questions buyers ask
Are the default prices JoySpool wholesale prices?
No. All defaults are editable illustrative assumptions. An actual grade, quantity, pack and delivery scope require a quotation.
Can a higher material price reduce part cost?
It can when other costs or yield improve, but the result needs your actual process data. The calculator exposes the assumptions instead of asserting an outcome.
Sources
- Formlabs — SLS cost per part
Packing, build height, refresh requirements and process costs; examples are specific to the referenced system.
- Formlabs — FDM, SLA and SLS comparison
Process and workflow differences; manufacturer-specific capabilities are not universal material approvals.