Parametric Portafilter Fork for Rancilio Rocky espresso grinder
by tprestero, published
Late night, trying to load coffee grounds into the filter in order to jump-start my brain with a jetfuel espresso, making a big mess because our Elektra portafilter is too big for the support forks on our Rancilio Rocky grinder. Isn't it time I learn how to use OpenSCAD anyway?
The result: a parametric portafilter support fork. Now anyone with a Rancilio Rocky coffee grinder can generate a support fork for their portafilter by plugging in their filter's exact outer diameter. The STL file is designed to print on the MakerBot Replicator 2 with support.
The included OpenSCAD file has loads of comments. I tried to cram in every OpenSCAD function I could think of, from modules and includes to mirrored geometry and recursion.
-- The code makes use of HarlanDMii's excellent Write function to add a motivational inscription for real estate salesmen. Note that it took some extra work to get the text to print on the inside of the cylinder.
-- There is generic code to create "mouse-ears" in the corners of the finished object, to prevent warping and lifting. The corners easily snap off the finished print.
-- The OpenSCAD file includes trouble-shooting code for generating model cross-sections, to verify that parts are lining up correctly.
-- The model is designed to be printed upside down using supports. Unfortunately, the latest Makerware (v22.214.171.124) adds hairy strands all over the model when printing with supports. so you'll have some finishing to do before you can make an espresso without making a mess.
More experienced programmers can probably point out a dozen ways to compress this code. Pictures to follow.
UPDATE: The print came out reasonably well from the MakerBot Replicator 2 using MakerWare with medium resolution with supports. Supports generated lots of messy "hairs" dangling off the print where no supports are necessary--not sure why that happened. Photos attached.