Finished Makerbot Objects

[Ian Johnson]

I'm not an operator, but more of a customer. I have objects I would
like to have made, but don't really want to pay print service prices,
and don't have the time to devote to building and tweaking my own bot
(though I would love to eventually). I am happy there are people like
Will who is willing to take orders through his Etsy store. Printing
with a Makerbot is much cheaper than the commercial systems, but the
big drawback is the low print resolution and rough surface. I am
happy to take on the extra effort of finishing pieces, in exchange for
the low price.

I've completed a project that fits in with the vision of "make it
instead of buy it". I have a Pottery Barn soap dish that is part of a
bath fixture set. It rests in a ring mounted to the wall, making up
for the lack of space on the edge of my pedestal sink. If the soap
sticks to the dish for a moment as you pick it up, the dish is prone
to tipping and falling through the ring, shattering against the
tiolet. This has happened so many times, continued repair is
pointless. Buying a new one is impossible, because the line is
discontinued, merely because I bought it (this is true of all the
dishes, drapes, silverware, etc in the house).

I decided that I would get a new one printed. I modeled half of the
dish, since it is too big for the Makerbot build area and sent the STL
to Will. He sent back the two halves, which I glued together with ABS
cement (found in the plumbing aisle of any hardware store). ABS
cement is ABS plastic melted in acetone and is fairly thick. I
thinned it out with some more acetone and dipped the dish in it. If
you need a color other than black, you can make your own by grinding
your filament and mixing the shavings with acetone until you have a
plastic sludge.

The surface came out smooth and glossy, but a bit uneven because the
solution was still too thick. I sanded it down to level out some
drips and finish hiding the seam between the two halves. Painting the
dip on with a foam brush restored the glossy smooth finish.

Rather than painting the dish white, I covered it with sprayed on
PlastiDip. This gave the dish a matte, slightly rubbery finish that
is more forgiving of imperfections than paint, and keep it from
sliding around on the ring. I've made a Flickr set of the various
steps, which you can find here:

http://www.flickr.com/photos/34519968@N03/sets/72157622911002038/detail/

The Makerbot is fine for creating parts where appearance is
unimportant, but it doesn't really make finished objects . Instead I
see it as a great tool for creating a base to build on. I could have
sculpted the dish in clay, made a mold and cast it in plastic.
However I don't have any skills in sculpting, but I can design an
object in 3D so I printed it instead and went from there.

By the way I found that the forum at mp3car.com is a good resource for
working with ABS. The people there are cutting up their dashboards
and fabbing custom bezels for their carputer screens

[Zach 'Hoeken' Smith]

whoa, thats epic!

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[Ethan Dicks]

On 12/1/09, Ian Johnson <ikelsey...@gmail.com> wrote:
> I'm not an operator, but more of a customer...
>
> http://www.flickr.com/photos/34519968@N03/sets/72157622911002038/detail/

Don't sell yourself short. That's an *excellent* use of the
technology. I'm much more of an operator than anything, which is why
my build team in Columbus has been trying to include folks who have no
interest in the mechanical aspects of 3D printing, but who have
visionary and creative skills. To me, the easy part is making the
printer - deciding what to print (beyond more printer parts ;-) is
much harder.

Thank you for an explanation of ABS cement. It's "obvious" in
hindsight, but I never thought of dissolving ABS swarf in acetone to
make color-matching cement. I will certainly be using that trick in
the future.

Thanks for sharing a great idea and a great story.

-ethan

[Zach 'Hoeken' Smith]

yeah, its a good idea to have a bottle with acetone next to your bot
that you throw all the extra junk in... like rafts and the first
extrusion, etc.

[Peter Davoust]

I wonder if it's even possible to skip the ABS cement step and simply
spray the model with a little acetone to melt down the outside layer a
little and smooth it out.

As for throwing extras in a bottle of acetone, I assume this just
turns into a block of ABS that can one day be recycled?

-Peter

[Zach 'Hoeken' Smith]

nope, all the little pieces dissolve and it makes abs glue that you
can use when you need. :)

[Peter Davoust]

Ah, ok. That's nice! I'll get some acetone and start doing that.

-Peter

[Cathal Garvey]

Already doing it, and the results are pleasantly murky! I gather if you evaporate off the acetone (I aim to attempt distillation instead to prevent wastage) you get a powdery residue rather than a solid block, too. Which either helps or hinders recycling into a 3mm rod, but using it as glue is fine too I guess! Anything to avoid plastic waste.

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twitter.com/onetruecathal

[Ian Johnson]

Nophead has done the acetone only thing, and has a picture here-
http://hydraraptor.blogspot.com/2009/04/glossy.html

It adds gloss to the surface without really changing the "made from
toothpaste" texture. To melt it smooth, you would have to completely
melt away the outermost "bead". Adding some plastic in provides
something to fill in the gaps. The trick is figuring out how much.
It didn't matter if I added a mm or so to the surface of the dish with
a thick mixture. If maintaining the dimension or detail is more
important, then you would want it thin enough that you could build it
up over a few coats. It would probably do a combination of filling in
the valleys and melting down the peaks until it smoothed out.

If you let the acetone dry out, you would get a new block of plastic.
I used a tupperware dish to dip, and poured the extra back into a
jar. Later I found that I had a paper-thin cast of the dish that
peeled right out. If you throw used chunks into acetone, it will take
hours or days for them to dissolve completely. If you want to create
a finishing solution and need to tweak the consistency, then it's best
to use shavings or pellets. The people at mp3car were using routers,
planers, etc on ABS pipe or sheets. I think using a bench grinder on
your discards would be a good method. For me the pipe cement was
perfect because it already had plastic in it, and I didn't car what
color it was.