Introduction: Cleaning-up Lo-res Plastic 3D Printer Parts

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About: I work in new york city at Eyebeam Atelier making robots that look like me and my wife michelle...

The following is step-by-step instructions for cleaning-up (i.e. sanding, filling, priming and painting) a low resolution plastic part. FDM machines are great, but the affordable ones create parts with a rough surface finish. These instructions, courtesy of FX artist, sculptor and toy maker Brett Klisch. For more info on the 3D printer and what it can do check out [http://www.robotclothes.comhttp://www.robotclothes.com/insideout/ robot clothes dot com]

Step 1: The Back Story

The Dimension BST is a great machine. It?s in the small-company price range and capable of producing functional prototypes with just a little post-build finishing and assembly. For exhibition or theatrical prop quality pieces, the surface finish is pretty crude. Curved surfaces are ribbed. Flat surfaces have thin patches where you can see the honeycomb subsurface. The limited build area often requires parts to be divided into multiple prints. The following is some step-by-step instruction in how Michelle and I clean-up the poor surface finish of simple FDM parts and seem two parts together.

The object we are demonstrating this process on is a replica 1/3 scale model of our living room table that Michelle is making for the set of our current project.

[http://www.robotclothes.com/insideout/archives/hprinterlarge.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/hprinterlarge.html','popup','width=480,height=640,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image of printer]

[http://www.robotclothes.com/insideout/archives/h1big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h1big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image of table]

Step 2: Tools

2. The tools we use:
a. Rigid Putty Knife
b. Glazing Putty by Bondo
c. Sand paper (250 ? 400 Grit, Wet-sanding pad)
d. Locking pliers
e. 5-Minute Epoxy
f. Dust Mask
g. Latex Gloves
h. White, Black or Grey Primer
i. Paint color of you choice

[http://www.robotclothes.com/insideout/archives/h22big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h22big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image ofputty and part]

[http://www.robotclothes.com/insideout/archives/h3big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h3big.html','popup','width=480,height=640,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image of putty knife, mask, part and sandpaper]

Step 3: Apply Putty

Apply the glazing putty directly to the surface of the piece. Squeeze out a small smear of putty on the part from the tube. Use the putty knife to spread it around. Try to spread a little bit of putty across as large a surface area as possible. You should be able to see the plastic surface through the translucent layer of putty. Remember to always close the tube between smear applications. The air will thicken the putty and it won?t spread around as well. Let the putty dry for 5 to 10 minutes.

[http://www.robotclothes.com/insideout/archives/h4big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h4big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

[http://www.robotclothes.com/insideout/archives/h5big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h5big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

[http://www.robotclothes.com/insideout/archives/h6big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h6big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

Step 4: Sand

Use 250 grit sand paper to sand the putty layer smooth. Sand in small circles until the surface is very smooth to the touch.

Step 5: Repeart Putty and Sand

Repeat Steps 3 and 4 two or three more times depending on the roughness of the original surface.

Step 6: Prime and Sand

Once you have gotten a few layers of putty on the piece to fill in the crack, apply 3 or 4 coats of primer in whatever color you'd like. Between each coat sand the painted surface with 300 - 400 grit sandpaper. Let the paint dry for 15-20 minutes before you handle or sand the part.

[http://www.robotclothes.com/insideout/archives/h7big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h7big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

[http://www.robotclothes.com/insideout/archives/h8big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h8big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

Step 7: Join the Two Parts

To join the two parts: mix up a batch of 5 minute epoxy. Apply a thin layer to both of the surfaces you want to join. We used the locking pliers to hold the parts in place. This is key when joining two parts. You have to find some way to preload the two surfaces together for 30-60 minutes. It is best to let it sit for a few hours to make sure the bond is strong.

[http://www.robotclothes.com/insideout/archives/h9big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h9big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

[http://www.robotclothes.com/insideout/archives/h10big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h10big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

[http://www.robotclothes.com/insideout/archives/h11big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h11big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

Step 8: Repeat Putty, Sand and Prime

Repeat Steps 3 - 6 three or four times until the seem between the two parts in nearly invisible.

Step 9: Top Coat

Once the primer surface is dry, you can apply your top coat of paint. In our case we used glossy white since our table is metal with a white powder coat. We applied three layers of white gloss, sanding the surface with a 400 grit sandpaper between every layer but the last. Finish off with your final layer of top coat.

[http://www.robotclothes.com/insideout/archives/h12big.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/h12big.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

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Be prepared for the inevitable scratch or chip. That is just life.

And don't be surprised if someone kicks you to the curb because of the fumes.

[http://www.robotclothes.com/insideout/archives/dark1large.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/dark1large.html','popup','width=640,height=480,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]

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When we finish the table, I will upload some images of the completed project and you can see Michelle?s gilded table legs.

[http://www.robotclothes.com/insideout/archives/mk.html" onclick="window.open('http://www.robotclothes.com/insideout/archives/mk.html','popup','width=480,height=640,scrollbars=no,resizable=no,toolbar=no,directories=no,location=no,menubar=no,status=no,left=0,top=0'); return false Click to view larger image]