Build the Machine Hourly Rate Honestly
A laser powder bed fusion system is a large capital item with ongoing costs: depreciation or lease, service contract, filters, optics and laser replacement, recoater blades, inert gas, chiller and power, and floor space with environmental controls. Add the operator and engineer time to prepare, load, unload and clean. Divide by realistic productive hours, not 8,760 hours a year.
Many bureaus run at 50 to 70 percent utilization once downtime, powder changeovers, maintenance and idle weekends are counted. A rate calculated at 90 percent utilization is a rate you will not earn. Recalculate it when utilization changes, because the machine cost does not shrink when the printer sits idle.
Plate Utilization and Nesting Yield
Cost per part depends on how many good parts share a plate. Utilization has two dimensions: footprint on the plate and height in the chamber, since recoat time scales with the tallest part. Nesting a short part beside a tall one wastes layers over the short part.
Group parts of similar height and keep a nest template library for repeat jobs. Track planned versus actual parts per plate and capture the reason when a plate runs partial, such as a customer deadline or an order that was not ready. That reason code is useful data: it tells you whether to hold work to fill plates or to price rush builds higher.
- Footprint fill percentage versus the usable build envelope
- Height spread across parts on the same plate
- Parts per plate planned versus actually built
- Reason code for partial plates
Powder Reuse Accounting
Powder is blended, sieved and reused, so the cost of a build is the net powder consumed, not the amount loaded. For each lot record virgin powder added, reused powder blended, powder lost to sieving and contamination, and the number of builds the lot has run. Customers with specifications often cap reuse cycles or require chemistry tests such as oxygen and nitrogen on reused lots, which adds testing cost.
Assign a cost per kilogram that blends virgin and reused material and charge builds with powder issued at that cost. Without lot-level accounting, powder expense lands in overhead and the margin on titanium and nickel alloy work looks better than it is.
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Plate Nesting Utilization and Material Cost per Part Worksheet
Enter sheet size, thickness, density, part area and parts per nest to get sheet weight, utilization percent and material cost per part for each job.
Failed Builds and the Cost of Scrap
A build can be lost to a recoater crash, power or gas interruption, lack of fusion, or distortion that breaks supports. When it happens, the machine time and powder are spent and the parts earn nothing. Do not hide this in the machine rate.
Track failed build hours and cost as a separate line, compute a scrap rate by alloy and part family over a rolling twelve months, and carry it into quoting as an explicit allowance. Also record reworked parts that pass after extra finishing, since they cost labor without showing up as scrap. This history is what lets the quote differentiate a mature bracket from a risky new geometry.
Where the Data Should Live
Printer job logs, powder lots, post-processing time and inspection results usually live in four different places: the machine software, a spreadsheet, the ERP and paper travelers. To get cost per part you need one build record joined to its parts, powder lots, machine hours and downstream operations. If your ERP supports job and lot tracking, make the build a parent job with child part jobs.
If it does not, a light MES or even a disciplined database is better than a spreadsheet. A reporting layer over this joined data can then answer questions like cost per part by alloy last quarter without a manual rebuild.
Frequently asked questions
What utilization should I assume for a metal 3D printer?
Use your own measured productive hours. Many shops land between 50 and 75 percent once maintenance, powder changes, setup and unscheduled downtime are subtracted, and a young bureau may be lower. Using a vendor brochure figure inflates the machine rate's competitiveness and understates the true cost per part, so recompute quarterly from the machine log.
How should powder reuse be costed?
Track each powder lot with virgin additions, blended reused powder, sieving loss and builds run. Charge each build at a blended cost per kilogram for the lot and add any chemistry testing the reuse policy requires. If a customer specification limits reuse, record which lots are eligible for which jobs.
Should failed builds be included in the machine rate?
Better to track them as a separate scrap-rate allowance by alloy and part family. Rolled into the hourly rate they become invisible and cannot be priced differently for risky geometry. A separate line also lets you see whether process improvements are actually lowering failure cost.
If your build costs sit across machine software, spreadsheets and the ERP, Netray can set up private, read-only question answering across them so cost per part is a query, not a month-end project.