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    <title>DEV Community: Walter Chen</title>
    <description>The latest articles on DEV Community by Walter Chen (@copper3dp).</description>
    <link>https://dev.to/copper3dp</link>
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      <title>DEV Community: Walter Chen</title>
      <link>https://dev.to/copper3dp</link>
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    <item>
      <title>Copper LPBF RFQ Checklist: Geometry, Material, Inspection, and Post-Processing</title>
      <dc:creator>Walter Chen</dc:creator>
      <pubDate>Fri, 17 Jul 2026 11:45:23 +0000</pubDate>
      <link>https://dev.to/copper3dp/copper-lpbf-rfq-checklist-geometry-material-inspection-and-post-processing-3b88</link>
      <guid>https://dev.to/copper3dp/copper-lpbf-rfq-checklist-geometry-material-inspection-and-post-processing-3b88</guid>
      <description>&lt;p&gt;A copper laser powder bed fusion request is much easier to evaluate when the engineering package connects function, material, geometry, finishing, and inspection. This checklist is intended for engineering teams preparing a first feasibility review for pure copper or CuCrZr components.&lt;/p&gt;

&lt;h2&gt;
  
  
  1. State the functional priority
&lt;/h2&gt;

&lt;p&gt;Start with the property that drives the design:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;thermal conductivity for heat spreaders and cold plates&lt;/li&gt;
&lt;li&gt;electrical conductivity for conductors and induction hardware&lt;/li&gt;
&lt;li&gt;strength at temperature for CuCrZr applications&lt;/li&gt;
&lt;li&gt;leak integrity for manifolds and heat exchangers&lt;/li&gt;
&lt;li&gt;low mass or compact packaging for aerospace and RF systems&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;A material name alone is not enough. Define the final condition, the required property, and the test method.&lt;/p&gt;

&lt;h2&gt;
  
  
  2. Identify the interfaces that control manufacturing
&lt;/h2&gt;

&lt;p&gt;Mark sealing faces, threaded features, electrical contacts, bearing fits, and datum surfaces. These are the locations most likely to need machining allowances or controlled surface finish.&lt;/p&gt;

&lt;p&gt;Avoid applying tight tolerances to every feature. A focused drawing makes the post-processing plan clearer and reduces unnecessary machining.&lt;/p&gt;

&lt;h2&gt;
  
  
  3. Review internal channels before releasing CAD
&lt;/h2&gt;

&lt;p&gt;For enclosed flow paths, confirm:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;minimum hydraulic diameter&lt;/li&gt;
&lt;li&gt;curvature and sudden area changes&lt;/li&gt;
&lt;li&gt;powder escape paths&lt;/li&gt;
&lt;li&gt;cleaning access&lt;/li&gt;
&lt;li&gt;CT or alternative inspection access&lt;/li&gt;
&lt;li&gt;pressure and leak-test requirements&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;Long blind passages and sharp dead ends increase powder-removal risk. Channel design should be reviewed together with build orientation.&lt;/p&gt;

&lt;h2&gt;
  
  
  4. Separate as-built and finished requirements
&lt;/h2&gt;

&lt;p&gt;The RFQ should distinguish:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;as-built geometry&lt;/li&gt;
&lt;li&gt;heat-treated condition&lt;/li&gt;
&lt;li&gt;machined interfaces&lt;/li&gt;
&lt;li&gt;polished or coated surfaces&lt;/li&gt;
&lt;li&gt;final inspection condition&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;This prevents confusion about which dimensions or properties apply before and after finishing.&lt;/p&gt;

&lt;h2&gt;
  
  
  5. Define the evidence required for qualification
&lt;/h2&gt;

&lt;p&gt;A practical verification plan may include density, dimensional inspection, conductivity testing, tensile coupons, surface roughness, CT, pressure testing, or flow testing. The smallest critical feature should drive the inspection method.&lt;/p&gt;

&lt;h2&gt;
  
  
  6. Supply a complete but concise RFQ package
&lt;/h2&gt;

&lt;p&gt;Recommended inputs:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;STEP model and controlled drawing revision&lt;/li&gt;
&lt;li&gt;material and final heat-treatment condition&lt;/li&gt;
&lt;li&gt;critical dimensions and datums&lt;/li&gt;
&lt;li&gt;machining allowances and finish requirements&lt;/li&gt;
&lt;li&gt;conductivity, density, and mechanical targets&lt;/li&gt;
&lt;li&gt;channel-cleaning and inspection requirements&lt;/li&gt;
&lt;li&gt;quantity, application, operating temperature, and delivery target&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;For additional copper additive manufacturing context, review &lt;a href="https://copper3dp.com/" rel="noopener noreferrer"&gt;COPPER 3DP's copper LPBF engineering resource&lt;/a&gt;.&lt;/p&gt;

&lt;p&gt;A structured intake page is also available for &lt;a href="https://copper3dp.com/rfq/" rel="noopener noreferrer"&gt;copper LPBF RFQ preparation&lt;/a&gt;.&lt;/p&gt;

&lt;h2&gt;
  
  
  Closing note
&lt;/h2&gt;

&lt;p&gt;Good copper LPBF results usually start before the quote. Early alignment on material condition, heat path, interfaces, support access, and qualification evidence produces a more reliable feasibility assessment and a more comparable commercial proposal.&lt;/p&gt;

</description>
      <category>design</category>
      <category>production</category>
      <category>science</category>
    </item>
    <item>
      <title>A Practical RFQ Checklist for Pure Copper and CuCrZr LPBF Parts</title>
      <dc:creator>Walter Chen</dc:creator>
      <pubDate>Fri, 17 Jul 2026 02:10:05 +0000</pubDate>
      <link>https://dev.to/copper3dp/a-practical-rfq-checklist-for-pure-copper-and-cucrzr-lpbf-parts-8i</link>
      <guid>https://dev.to/copper3dp/a-practical-rfq-checklist-for-pure-copper-and-cucrzr-lpbf-parts-8i</guid>
      <description>&lt;p&gt;Copper LPBF projects move faster when the RFQ is treated as an engineering data package instead of a short request for a price. This checklist is intended for hardware teams, thermal engineers, product developers, and sourcing teams preparing a pure-copper or CuCrZr part for additive manufacturing.&lt;/p&gt;

&lt;h2&gt;
  
  
  1. Confirm why additive manufacturing is being used
&lt;/h2&gt;

&lt;p&gt;Start with the feature that creates value:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;internal cooling channels that cannot be drilled;&lt;/li&gt;
&lt;li&gt;compact heat exchangers or cold plates;&lt;/li&gt;
&lt;li&gt;integrated manifolds that reduce joints;&lt;/li&gt;
&lt;li&gt;induction coils with controlled flow paths;&lt;/li&gt;
&lt;li&gt;RF, vacuum, semiconductor, or power-electronics hardware;&lt;/li&gt;
&lt;li&gt;low-volume parts where tooling would dominate cost.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;If the part is a simple block, tube, or plate, conventional machining, extrusion, brazing, or a hybrid route may be more economical. LPBF is strongest when geometry, integration, or iteration speed matters.&lt;/p&gt;

&lt;h2&gt;
  
  
  2. Select the copper alloy around the operating requirement
&lt;/h2&gt;

&lt;p&gt;&lt;strong&gt;Pure copper&lt;/strong&gt; is usually the starting point when electrical or thermal conductivity dominates and the component is not heavily loaded.&lt;/p&gt;

&lt;p&gt;&lt;strong&gt;CuCrZr&lt;/strong&gt; is often preferable when the part also needs strength, fatigue resistance, dimensional stability, or repeated thermal-cycle performance. It gives up some conductivity in exchange for a more balanced mechanical profile.&lt;/p&gt;

&lt;p&gt;Do not specify the alloy name alone. Include the property that drives the choice: thermal conductivity, electrical conductivity, proof strength, hardness, maximum temperature, pressure, or cycle life. If a post-heat-treatment value is required, say so explicitly.&lt;/p&gt;

&lt;h2&gt;
  
  
  3. Mark the geometry that controls feasibility
&lt;/h2&gt;

&lt;p&gt;A supplier should be able to identify these features directly from the model and drawing:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;minimum wall and fin thickness;&lt;/li&gt;
&lt;li&gt;channel diameter or hydraulic dimension;&lt;/li&gt;
&lt;li&gt;unsupported spans and overhangs;&lt;/li&gt;
&lt;li&gt;sealing surfaces;&lt;/li&gt;
&lt;li&gt;threads, bores, datums, and mating interfaces;&lt;/li&gt;
&lt;li&gt;areas that may receive support material;&lt;/li&gt;
&lt;li&gt;machining stock;&lt;/li&gt;
&lt;li&gt;internal surfaces that must be cleaned or inspected.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;For channels, provide inlet and outlet sizes, required flow direction, pressure, media, cleanliness, and the acceptance method. A hidden passage is not just a geometric feature; it is also an inspection and post-processing problem.&lt;/p&gt;

&lt;h2&gt;
  
  
  4. Define the finishing route before quoting
&lt;/h2&gt;

&lt;p&gt;Copper AM parts often need several linked operations:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;LPBF build and support removal;&lt;/li&gt;
&lt;li&gt;stress relief or alloy-specific heat treatment;&lt;/li&gt;
&lt;li&gt;CNC machining of interfaces;&lt;/li&gt;
&lt;li&gt;surface finishing or cleaning;&lt;/li&gt;
&lt;li&gt;dimensional, pressure, leak, conductivity, or material inspection.&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;The sequence affects datums, distortion risk, machining allowance, and final delivery time. State which surfaces may remain as-built and which require a numerical roughness, flatness, or tolerance.&lt;/p&gt;

&lt;h2&gt;
  
  
  5. Turn the RFQ into structured data
&lt;/h2&gt;

&lt;p&gt;A compact machine-readable summary helps internal teams and suppliers check completeness. For example:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight yaml"&gt;&lt;code&gt;&lt;span class="na"&gt;part&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;name&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;liquid-cooled copper manifold&lt;/span&gt;
  &lt;span class="na"&gt;alloy_preference&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;pure copper&lt;/span&gt;
  &lt;span class="na"&gt;quantity&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;6&lt;/span&gt;
  &lt;span class="na"&gt;revision&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;C&lt;/span&gt;

&lt;span class="na"&gt;operation&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;media&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;deionized water&lt;/span&gt;
  &lt;span class="na"&gt;max_temperature_c&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;80&lt;/span&gt;
  &lt;span class="na"&gt;max_pressure_bar&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;6&lt;/span&gt;
  &lt;span class="na"&gt;leak_test_required&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;

&lt;span class="na"&gt;critical_features&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;min_wall_mm&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;1.2&lt;/span&gt;
  &lt;span class="na"&gt;smallest_channel_mm&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="m"&gt;3.0&lt;/span&gt;
  &lt;span class="na"&gt;machined_interfaces&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;inlet face&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;outlet face&lt;/span&gt;
    &lt;span class="pi"&gt;-&lt;/span&gt; &lt;span class="s"&gt;mounting datum A&lt;/span&gt;

&lt;span class="na"&gt;inspection&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;dimensional_report&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="na"&gt;pressure_test&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="kc"&gt;true&lt;/span&gt;
  &lt;span class="na"&gt;conductivity_report&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;requested&lt;/span&gt;
  &lt;span class="na"&gt;material_certificate&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;requested&lt;/span&gt;

 &lt;span class="na"&gt;delivery&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt;
  &lt;span class="na"&gt;destination_country&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;Germany&lt;/span&gt;
  &lt;span class="na"&gt;target_date&lt;/span&gt;&lt;span class="pi"&gt;:&lt;/span&gt; &lt;span class="s"&gt;2026-09-15&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;The values above are only an example; the useful practice is to make assumptions visible. A drawing and 3D model remain essential.&lt;/p&gt;

&lt;h2&gt;
  
  
  6. Ask questions that expose risk early
&lt;/h2&gt;

&lt;p&gt;Before accepting a quote, ask:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;Which features drive build orientation?&lt;/li&gt;
&lt;li&gt;Where will supports be attached?&lt;/li&gt;
&lt;li&gt;How will internal powder and debris be removed?&lt;/li&gt;
&lt;li&gt;Which surfaces need machining stock?&lt;/li&gt;
&lt;li&gt;What heat treatment is planned?&lt;/li&gt;
&lt;li&gt;How will channels be inspected or tested?&lt;/li&gt;
&lt;li&gt;Which requirements are included in the quoted price?&lt;/li&gt;
&lt;li&gt;Which assumptions could change lead time?&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;A good engineering review may recommend a geometry change, an alternate alloy, or a hybrid process. That is useful information, not a failure of the model.&lt;/p&gt;

&lt;h2&gt;
  
  
  A concise RFQ package
&lt;/h2&gt;

&lt;p&gt;The minimum practical package is:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;STEP or another manufacturing-ready 3D model;&lt;/li&gt;
&lt;li&gt;dimensioned drawing with datums and critical tolerances;&lt;/li&gt;
&lt;li&gt;alloy and property requirements;&lt;/li&gt;
&lt;li&gt;quantity and revision;&lt;/li&gt;
&lt;li&gt;operating temperature, pressure, media, and duty cycle;&lt;/li&gt;
&lt;li&gt;post-processing and finish requirements;&lt;/li&gt;
&lt;li&gt;inspection and documentation requirements;&lt;/li&gt;
&lt;li&gt;delivery location and target date.&lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;&lt;a href="https://copper3dp.com/" rel="noopener noreferrer"&gt;COPPER 3DP&lt;/a&gt; coordinates pure copper and CuCrZr LPBF production with heat treatment, CNC machining, finishing, inspection, and export support for industrial parts.&lt;/p&gt;

&lt;p&gt;A longer design and RFQ guide is available here: &lt;a href="https://copper3dp.blogspot.com/2026/07/designing-pure-copper-and-cucrzr-parts.html" rel="noopener noreferrer"&gt;Designing Pure Copper and CuCrZr Parts for Metal Additive Manufacturing&lt;/a&gt;.&lt;/p&gt;

&lt;p&gt;The goal is not to make an RFQ longer. It is to make the decision-critical information explicit before build planning begins.&lt;/p&gt;

</description>
      <category>3dprinting</category>
      <category>manufacturing</category>
      <category>tutorial</category>
      <category>productivity</category>
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