Sunday, July 21, 2013

Further 3D Printing Tests





















After working with the Form 1 since the last update, I've obtained a better understanding of the capabilities of the printer in addition to many necessary printing design considerations.  In the meantime I've printed an array of objects pulled from the internet to do so.

Failed heartbox print due to drooping lids
and inability to open / rotate.















For example, I printed a popular 3D secret heartbox which is an object that works really well when printed using a standard FDM printer--easily opening up, rotating / transforming, etc.  However, things didn't work as smoothly when printed from resin using SLA.  One issue that is of concern is the fact that a small amount of resin can get trapped in the interior of the box as it's printing, added to the fact that after the object is printed, a viscous layer of resin is coating the build platform and part, creating a sticky mess that takes a large amount of rinsing in isopropyl alcohol to clean off.  This stickiness is a very large hindrance in the smooth / proper operation of printed rotating hinges.  Standard FDM prints from PLA plastic or ABS are smooth and dry so "built-in hinges" work very well--the opposite is true when printing from resin.  If the rotating hinge joint is able to be rinsed extremely well and fully-dried it may be possible to get smooth rotating action, but with complex models this may be completely impossible.  Therefore it seems like rotating joints will need to be printed in multiple pieces and assembled after the fact.

A fancy Möbius strip and a crystal.















Solid objects with decent (>9 mm2 square solid) thickness print extremely well and are very rigid and strong.  However, thin objects are very soft and flexible when newly printed and are easily prone to being damaged until the "solvent-like" excess resin is washed away.



























I tried printing a complex phone case but the results were disastrous as the object would delaminate in sections when printed directly onto the build platform without supports.  The printed parts adhere extremely strongly to the steel build platform as well and require massive amounts of force to remove, causing fragile parts to be easily damaged during removal--which is what happened when trying to peel the phone case off the build platform.  A second printing attempt was made using supports, however, the supports are still extremely strong in bulk and are not easily "peeled away" when the printed part is thin and fragile.  An exacto knife is likely necessary to cut delicate parts free from the supporting structures.

















A friend made a request for a large "bracelet-sized" Möbius strip after seeing the miniature version above, so that part is currently being constructed at the moment.  Additionally, I've received requests for 3D printed wearable jewelry, so that is next on the agenda.  I have some ideas in mind which I'll be attempting to draw in CAD and prototyping shortly.


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