Functional metal DMLS prototype series

The brief

An engineering client needed a small series of structural aluminum parts to validate a mechanical assembly before committing to tooled production. The geometry included internal channels that could not be reproduced by CNC machining alone. Lead time was critical — they had a testing window and a product launch date that depended on it.

Why DMLS was the right choice

Three factors pointed away from traditional manufacturing and toward Direct Metal Laser Sintering:

• Internal channels — integrated fluid passages that cross through the part body. Impossible to machine without splitting and rejoining, which would have compromised structural integrity.
• Geometry complexity — organic, load-optimized shape that was designed for additive manufacturing from the start.
• Low quantity, high value per part — tooling-based production would have been 10x the cost and 4x the lead time for the volumes needed.

Process

1. DfAM review — one-hour call with the client to review the CAD and flag any geometry that would fight the DMLS process (overhangs, thin walls, support-trapped cavities). Minor adjustments were suggested and accepted.
2. Material selection — AlSi10Mg (aluminum-silicon alloy) for the combination of strength, weight, and post-T6 heat treatability.
3. Build — parts printed in a single build with support structures optimized for minimal post-processing.
4. Post-processing — support removal, stress relief, T6 heat treatment, bead blasting, and a dimensional inspection report.
5. Handover — finished parts delivered with an inspection report against the CAD model.

Results

• Ten working days from CAD handover to delivered parts.
• Passed all functional tests on the first iteration — no reprints required.
• Weight reduction of 32% versus the original machined design (which the DMLS geometry replaced).
• Client moved to volume production on the validated design with confidence.

Key takeaways for engineers evaluating metal 3D printing

1. DMLS is not a replacement for machining — it is a complement. Pick it when geometry demands it or when lead time and low quantity make tooling uneconomical.
2. Design for AM early. Parts designed for subtractive methods and converted later rarely perform well. The best DMLS results come from geometry conceived for the process.
3. Post-processing matters. Heat treatment and surface finish can change mechanical properties significantly. Plan them into the spec from the start.
4. Budget for QA. A dimensional inspection report is not a luxury — it is how you know the part you are testing matches the digital design.

Have a similar project?

We offer a free 30-minute DfAM review for any metal 3D printing project. We will look at your geometry, flag potential issues before you commit, and give you a realistic budget and lead time range.

Get in touch or read more on the 3D printing service page.