Hello, my name is David Pello and I'm from Asturias, North Spain.
I work at LABoral arts and industrial creation centre as the manager of the production centre and labs, and will be the one in charge of the Asturias FabLAB (opening soon).
My idea for my final project is the design, construction and programming of an open source platform for high altitude balloon tracking, including structure (support, thermal isolation, etc), and electronics (MCU, radio transmission, gps, sensors, etc).
Classes > Molding, casting, and composites
I've been printing a part in the makerbot a lot of times. It's a support for making yagi antennas (I'm a radio amateur), so for the assigment of this week I thougt it'll be great to make a mould for it, so I can make these parts faster and cheaper, and also try some other materials than ABS plastic.
So I started designing the moulds for the casting. I decided to go with the positive mould/silicon negative mould/positive part method. As I designed the part in OpenSCAD, making the mould was not hard, using the part as a module, and using some boolean operations with prisms, this work was done.
Then I exported the STLs and went to the modela to machine them. I used polyurethane foam I had at the lab to test the moulds, and after milling them they looked really nice.
Here you can see the test pre-moulds.
After this, I machined the wax pre-moulds..
and used silicon to make the final moulds.
Then I used polyurethane to cast the part.
I got some bubbles in the process, but the part is nice and hard.
Here you can see the part working as intented, supporting an aluminium element for a yagi antenna. The legs are designed to mantain the part perpendicular to the antena boom, and are parametric (all the design is).