================================
 Some objects I printed
================================
:CreationDate: 2009-09-07 15:32:20
:Id: HW/makerbot/printed-objects
:tags: - hardware
       - 3dPrint

The round 12-sided die
======================

A friend of mine, member of my D&D group, asked me, as soon as he
discovered that I would get a 3-D printer: «can you print me the
intersection of three cylinders?»

New, the resulting object is not exactly easy to visualize, but it's a
12-sided solid, where each side would be a square, were it flat; in
fact, the sides are curved.

Obviously there is no way to print an object similar to a sphere on
the CupCake: we would need some support material. What we can do,
instead, is to print a half-sphere; we print it twice, we glue the
halves together, and we get a sphere.

[% WRAPPER 'figure.tt' pic='img_0980' alt="half-die, from an edge" %]
Half of the die, seen from an edge
[% END %]

[% WRAPPER 'figure.tt' pic='img_0981' alt="half-die, from above" %]
Half of the die, seen from above
[% END %]

[% WRAPPER 'figure.tt' pic='img_0982' alt="half-die, from the side" %]
Half of the die, seen from the side
[% END %]

[% WRAPPER 'figure.tt' pic='img_0983' alt="half-die, from the side and
edge" %]
Half of the die, seen from the side, looking at an edge
[% END %]

[% WRAPPER 'figure.tt' pic='img_0984' alt="half-die, upside-down" %]
Half of the die, upside-down. It rolls well enough, after a little sanding
[% END %]

[% WRAPPER 'figure.tt' pic='img_0985' alt="half-die, from the top" %]
Half of the die, seen from the top: it's a very good approximation of
a circle
[% END %]

Sadly, the two halves have warped a bit during printing, and it will
not be easy to glue them in such a way as to keep them "round".

The benchmark piece
===================

Just to try it out, I printed `the RepRap benchmark piece
<http://www.thingiverse.com/thing:968>`_.

First problem: the raft wasn't sticking to the build base; solved by
keeping the extruder nearer to the base.

I discovered immediately afterwards that the build base was not
precisely horizontal; I don't know whether the plastic build base is
distorted, or the translation axes are somehow misaligned (hard to
believe).

After about forty minutes of printing, I notice that the model is
distorted; it happens quite often, but this time it's warping the
build base! In fact, I soon had to abort the print: the base had
detached from the wooden support that holds it to the Y stage, and the
extruded filaments were going every which way.

Results:

[% WRAPPER 'figure.tt' pic='img_0992' alt="half the benchmark piece" %]
This is all I could print before having to abort.
[% END %]

[% WRAPPER 'figure.tt' pic='img_0993' alt="warped piece" %]
See how bent it is.
[% END %]

[% WRAPPER 'figure.tt' pic='img_0995' alt="warped piece, from the side" %]
From the side it's even more noticeable.
[% END %]

[% WRAPPER 'figure.tt' pic='img_0997' alt="warped base, from the side" %]
And this is how much my build base has bent…
[% END %]

To do for next time:

* check the orthogonality of the base
* use the bolted build base, instead of the one held with double-sided tape