Thursday, June 5, 2014

Ellipsoid


After a break, I am back at it. Yesterday's print was an ellipsoid. It is around 3.5 inches tall and took around 5 hours. Of course at a fraction the price,  I could have just purchased a package of M&Ms for the course demo. (First donuts, now M&Ms - is geometry somehow linked to dessert?)  In a future iteration, I plan to remove the remaining circular symmetry and make it an ellipse in every direction. No item in the candy aisle does that. 



Technical comments:
My first attempt was to print it to be short, but it is the overhang that matters. The front of this image shows the aborted print, where lots of filament was dripping down. The back  shows the bottom of the successful print - still a bit of drip.


Due to wanting to increase the size, I tried a modification  by adding a support in Tinkercad. 
I am currently reprinting it at 1.5 times the size. However, it seems this involves taking  more care than I gave it, because the supports do not seem to be touching the bottom. However, it seems to be doing well so far - estimated to take 11 hours.  

One day later update: First spectacular failure!  It seems that one must be very careful to get the supports right with a larger piece.  It seems that it fell over while printing, creating a lot of angel hair filament in the course of it. Well, back to the virtual drawing board. Planning to take inspiration from the support structure on the Sierpinski Tetrahedron by Owens.