Tuesday, December 1, 2009

Finishing 3D Printed Prototypes

3D printers produce amazing prototypes for a relatively low cost. However the parts often have a surface finish that is less than ideal for market testing, investor demos and production one offs. The printed parts can be finished to look very similar to injection molded parts without the significant investment injection molding requires.

Step 1: Sand your parts with 120-150 grit  sand paper

Step 2: Paint your parts with an enamel paint or primer. The suggested drying times will usually be something strange like repaint in 1 hour or after 24 hours. These drying times should be followed closely to ensure proper curing of the resins in the paint. The time to cure the resins can be improved by baking the parts in a warm dry place.

Step 3: Sand your part using 240 grit sand paper followed by 400 grit. Until smooth. If it is not smooth before the final coat, if will not be smooth after.

Step 4: Repeat steps 2 and 3 until finished.

If you are impatient and do not let the paint properly dry, the results may be unsatisfactory. Resand and repaint until satisfied.

This is the finished case for a Gumstix Palo35 display board and Overo computer module.

The part is finished when you get tired of sanding or when you run out of paint.

If anyone is interested in buying a case for their Gumstix Palo35 or Palo43, send an email to iheartrobotics at g mail.


Leshell said...

Nice work! Congrats.

I'm working on a similar project. I'll keep you posted.

Thanks for sharing!

Robotbling said...

It might be better to use modeling putty as a filler rather than paint... it fills the gaps better and can be sanded to a nice finish. Then prime and paint for best results.

I Heart Robotics said...

I couldn't find any putty but I'll try that next time.

It only took one coat of sign painter's enamel paint to fill in the gaps. Enamel paints are pretty similar to plastic because of the resins in them. You can more or less think of enamel paint as paint + epoxy. Which is why it has the weird drying times.