After 21 month and seven prototypes i proudly present you a first version of my Open Exposer 3D resin printer which is able to print.
Open Exposer is a low budget open-hardware 3D resin printer i am working on. It uses a polygon mirror instead of laser galvanometers. When the laser hits the polygon mirror, a laser line is projected. By rapidly turning the laser on and off, i can produce any line pattern. By moving this changing line pattern in y-direction i am able to expose a whole layer.
Current hardware setup
For the first prototypes i decided to keep things simple, so i used a “reprap” design with printed parts, threaded rods and nuts. Later i will switch to a laser cut approach. For the vat i used a petri dish. Two stepper motors move the y and z axis.
The controller is a rough prototype until now. It consists of an Arduino with a fabscan shield on it for driving the motors. A small laser driving TTL circuit is used to control the laser diode. The last part is a Atiny2323 which generated a 33,333 MHZ signal to drive the polygon mirror.
Laser exposing like described above.
For slicing the STL files to SVG i use the SVG slicing option of Slic3r. After the slicing process, a python written post processor is called, which converts the SVG to Open Exposer G-Code. Then a host software sends the G-Code to the Open Exposer. There is a lot of work to do!
The video shows the layer changing procedure.
Results until now
The printing results are looking good. A lot of work is to do. And i am sure there can be a lot of optimization to get even better results.
All needed files to build an Open Exposer can be found at: https://github.com/mariolukas/openexposer/
I will keep you up to date.