Hi,

I wanted to print the longest object possible with Shapeways. I though the main limitations were:

- the bounding volume (15x15x15cm for White Strong and Flexible Polished)

- the number of triangles (1,000,000 now, but I remember a time when you could bypass this limit)

I needed something that could be unfold to get bigger than this initial volume, so I choose to design a simple chain.

I first designed a simple link made of two circular loops, intersecting in a perpendicular direction by their sides (two tori to be precise).

I reduced the number of polygons as much as I could without scarifying the shape, and the result was an object with 1176 triangles.

Then I put as much of these links as I could to make a closed loop.

My first attempt was a loop of

**824** of those links (

**969,024 triangles**). As you can see, in theory, I could put 26 more links but it was not esy because the chain had to form a closed loop, so the end of the chain had to join the beginning of it, whereas staying into the maximum bounding volume. In other words, I had to fold the chain several times to fit it into this volume and thus the total length had to be a multiple of a certain basic length.

Unfortunately when I uploaded the model, I got an error, saying basically that the Meshmedic program (that check if all is OK with your model) failed to merge the shells. This was quite frustrating because there is no shell to merge: each shell (separate part) is interlocked with two other, but non is intersecting another.

But this means that the number of shell (probably also depending on the number of polygons) is an

**undocumented limit**.

So I reduced the number of shells to 758 then to 692 and finally the 626-link version was uploaded successfully.

So the

version available is made of 626 links and has 736,176 triangles, which is not bad at all. Each link add a length of 6 mm so the total length is in theory 3.76 meters. As there is a clearance of 0.5mm the actual length is more that 4 meters (that you have to fold into two since it is a closed loop).

Here is a video of the result (with a bit of me for the scale) :

http://youtu.be/yfSM1TBtBrc
And you, did you manage to print something bigger? In this case how many shells and how many triangles?