Week 11 - Machine Design - Marbled Paper Machine
Click to see a new 1 min video of the process of making marbled paper with our machine
What is Marbled Paper?
Marbling paper is a way of making designs with ink on the surface of a water solution and then transferring them to paper. It is an ancient technique, with references from 800 bc in China. It is used today to create images for use in bookbinding.
We built a machine that manipulates ink to make designs on the surface of water
We modified a machine that was partly assembled in our lab. It has an aluminum frame, 2 stepper motors for the x axis, one stepper motor for the Y axis, and a servo to make a simple up and down movement in the Z axis.
We designed combs parametrically in Grasshopper (thanks for the help Eduardo!) so we could easily make different combs with different width and spaced teeth. We designed and cut legs for the machine on the laser cutter.
The electronics are run by an arduino uno with a shield. We create a drawing in Inkscape that is a path for the movement we want, then use a plug-in (gcodetools) that creates a generalized gcode for the path. GRBL then changes the gcode into commands that move our machine. GRBL firmware is loaded into the arduino, the arduino takes GCODE from the PC and converts it into movements of the stepper motors via GRBL.
See more examples of gcode at the bottom of this page
5 V Slot Bars 40x20x1 3 Neema 17 Motors 1 Sevo 3001 HB Arduino CNC Shield 2 Drivers DRV8825 9 Plastid Coated Bearings 3 Belts 3 Pulleys HP2 GT2 20T 1 Sky Top Power STP 3005 Power Supply 12V. 2A. Rough cost new: 200 - 300 euro
Click to see a 1 min video of the process of making marbled paper with our machine
We had issues with triggering limit switch stops at inappropriate times. The long axis stepper would stop mid travel. We resolved it by disconnecting the short axis stepper limit switch - not sure why this resolved it. Looking on line, it was reported in several places that electrical noise can cause limit switch triggers. We cleaned up the wiring and tried to do isolation form noisy motors but that didn’t resolve the issue. Disconnecting the short travel axis limit switch resolved the long axis false trigger issue.
We had an issue with activating the z axis servo. We needed to try several different kinds of software to resolve the issue. We also had a hardware issue - the original servo had broken gear teeth, we replaced it.
Ximena is from Mexico City where earthquakes are common. She would like to continue with the project and and simulate the effects of different intensity earthquakes in the designs that the machine makes, perhaps by shaking the water pan at exponential intensities reflecting the Richter scale. One set of legs we made for the machine accomodate shaking the machine.
click here to see gcode samples from the Inkscape plug in gcodetools
Machine Assembly Drawings (Thanks Daphne!)