When designing for 3D printing I often find that students “push their luck” and sometimes incorporate features into their designs that even with several years experience in 3D printing I personally wouldn't even attempt.
Well that's exactly what happened this week. Some of my students are doing a tried and tested printing project that I have done with several groups … Design and make a bespoke USB stick case. Anyway, one of my students got carried away adding a surface texture of 1mm diameter bumps and a tiny hole (1mm square) right through the lid of his USB stick. I smiled to myself and warned the student that these wouldn't show on the final print…. And you've guessed it… They did! Each of the bumps is clearly visible and yes the hole does actually go right through. (Maybe a bit of swallowing of humble pie needed?)
Click the above picture to see a larger version.
And here are a few technical details… The lid is 20x14x12mm wall thickness is variable but approximately 1.5mm. The object was printed in ABS using a Bits from Bytes 3D Touch machine at a medium layer thickness of 0.25mm (now I'm wondering what would be possible with 0.125mm layers). The g code generation software was Axon 3 (alpha).
Oh, and if you fancy doing the project in schools then I have produced a free lesson resource that can be downloaded here http://wiki.bitsfrombytes.com/index.php/Bespoke_USB_Stick