How to price SLS 3D prints.

Start with the part's volume

SLS has no supports and no infill choice, so the part's solid volume in cm³ is the base. Multiply it by what a cm³ of printed part costs you. That isn't the powder price alone, because of the next two points.

Powder you pay for and don't print

The powder around your parts heats up during the build and ages. You can reuse most of it, but each build needs some fresh powder mixed in. The machine maker tells you the ratio. That fresh powder is a cost of every build, so spread it across the parts in it.

An easy way to do it: work out what a whole build costs you in powder (fresh powder added, plus what you throw out), and divide by the cm³ of parts you usually get out of one build.

A full build is a cheap build

Print time follows the height of the build, not how many parts are in it. A build that's packed full costs about the same to run as a half-empty one. So:

• Price machine time per build, then share it by each part's volume or the space it takes up.
• Decide how full you assume a build is. If you price as if every build is packed, you lose money on the ones that aren't.
• A customer in a hurry who can't wait for a full build is paying for empty space. That's a rush fee.

Cooling, depowdering and finishing

• Cooling. The build has to cool before you open it, often for hours. That's machine time you can't sell.
• Depowdering. Digging the parts out and blasting off the powder is hands-on time, per build and per part.
• Finishing. Dyeing, smoothing or sealing are extras. Price them on their own lines.

A worked example

These numbers are made up to show the maths. Use your own.

• The part: 30 cm³ of nylon.
• Powder: $0.20 a cm³ of printed part, including refresh = $6.00
• Machine time: 14 hours of building and cooling at $6.00 an hour is $84, and this part takes 1/12 of the build = $7.00
• Depowder and blast: 6 minutes at $40 an hour = $4.00
• Failures: 5% = $0.85
• Cost: $17.85. With a 40% markup, about $24.99, or $0.83 a cm³.

Charging the powder price per cm³ alone would have priced it at a quarter of that.

Minimums

A tiny part still needs a slot in a build, depowdering and packing. Set a minimum per part or per order.

Check your numbers

The free price checker has SLS materials priced per cm³. Drop an STL and compare a fair range with what you charge. For resin, see how to price resin 3D printing.