Test Print Time
Before I commited to a print from an outside source, I needed to know that Beary Poppins was stable. One disadvantage of ZBrush is that it’s not a CAD package as such, so doesn’t offer many engineering considerations or ‘real world’ dimensions. One of these being the design’s centre of gravity.
Fortunately, my son Lewis is a game designer and has a 3D FDM printer for creating game pieces. I could call upon his Ultimaker 2 to output a low resolution model to test for stability and scale.
Using my newly-acquired exporting/scaling ability, I created an STL file to the correct size and put the result through a ‘slicing’ application.
This does exactly what it sounds like, creating a sequence of paths for the printer to follow. I liken FDM printers to a glue gun on a plotter. A stream of molten plastic is spiralled out, layer upon layer, to eventually create the printed form. The slicing softaware also adds supports which are printed with the job. These provide a platform on which overhangs can be created. Imagine building a house from Lego, beginning with the roof. Without walls to build up from, gravity intervenes and stuff doesn’t stay floating in mid air for long, resulting in an ugly mess on the printing platform.
The printer works from what looks like fat fishing line feed from a reel. There was a short length of silver metallic in the feed pipe which proved tricky to remove, something to do with it being beyond the point of reversing it out, so we simply pushed it through with the white opaque that I’d intended. This meant that there was a silver base to my white model. No bother. It’s only a proof.
Once this was all done, Lewis and me set the print going and off he went to work. Even at this medium quality, it was to take around eighteen hours to complete the print.
I confess, I was a little giddy with excitement - my first ZBrush model, my first Bad Taste Bear figurine zizzing out of a printer nozzle! I took lots of progress shots and videos - more in fact than is decent, but I wanted to capture the occasion.
Eventually, the following morning, the print was complete, however, the supports applied by the slicing software prevented me getting a good look. The support needed to be removed, not least because it was material that wasn’t going to be present on the final piece, so could have an effect on stability.
Luckily, the crispy support material was relatively easy to remove with needle-nosed pliers, even though it seemed to take hours, most came away relatively easily. The point where the support was necessary and logically in contact with my model needed sanding to tidy up, but for now, the main thing is to assemble the elements and check stability.
You can probably imagine the relief I felt when the bag insert slid into place (after a little sanding) and Beary Poppins remained upright. Solid and upright! Phew!