This document provides tips for finishing 3D printed parts in one step to achieve a shiny production-ready surface. It recommends starting with high-quality prints using small layer heights and infills. The main steps are to sand the print with gradually finer grit sandpaper from 100 to 2000 grit, washing occasionally to check for imperfections. This process smoothes the surface until it becomes very clean using 600 grit or higher. An optional final step is using a plastic polish compound to achieve an injection-molded plastic-like shine.

1. Finishing 3D Printed Parts in One Step
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2. • All hardware want to show off their production
ready shiny prototypes.
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3. Start with a good print
• 3D printing isn’t like magic yet. So practice good
printing techniques in general.
• Learn the settings in the slicer.
• Choose a filament with final desired color or close
to it to avoid requirement of heavy painting later.
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4. • Use the smallest layer height (which in most printer is .1mm
or less). This is absolutely important. Make sure the first
layer is also printed in smallest height (or highest
resolution).
Striation or stringy surface when printed with large layer height.
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Start with a good print

5. • We started with the face plate upside down (attaching to
the hot plate) to get the best finish to start with.
• Start with a new Kapton tape (for ABS) and clean the surface
to get rid of any debris. We used IPA (from Walmart,
optional) to remove surface oil, if any
• For finer features, use slower speed. Avoid faster speed in
general if not absolutely necessary.
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Start with a good print

6. • Use a dense infill. We used 100% infill, But a thicker shell
may also suffice. (A good amount of material is removed
while sanding).
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Start with a good print

7. Sanding
• Use five to six gradually increasing grades of sand paper (we
used papers with grit 100, 240, 400, 600, 1500 and 2000).
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8. Sanding
• Sanding with 100 grit is the most important part to remove any odd bumps or
deep scratches. We washed it occasionally to verify. Its very important to verify
in every stages (under good light) or else, once moved up to higher grit papers,
the scratches neglected will become prominent and may have to start over.
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9. Sanding
• Initially the surface will look ashed.
Sanded with 100 grit paper
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10. Sanding
• However once you start using 600 and higher, the surface
will start to become cleaner and it becomes very smooth.
Sanded with 600 grit paper
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11. Polish (Optional)
• Plastic finish compound was bought from walmart (~$6). It
gives you a shine that is comparable to a regular injection
molded plastic.
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12. Question?
• More detail on: https://rumy.io/blog/finishing-3d-
printed-parts
• Go to https://rumy.io and click contact.
• Thanks for reading through.
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