1 Attachment(s)
Using an existing cnc machine for 3d printing
I posted some time ago about using Mach3 with an existing cnc machine to do 3D FDM printing . The needed additions are a 4th axis to run an extruder stepper motor, a PID thermostatic temperature controller and a build bed from Gnexlab
Mach3 runs a old XYZ stage that I have had for 15 years and was used for drill printed circuit boards. The advantages of the machine were that the XY axis have ballscrews and thus are very precise. The XY stages are on precision linear guides.
I mounted a stepper plastruder extruder on the Z axis and wired it the a dual extruder and build bed temperature controller. For drivers I used the awesome Geckodrive G540. It runs the machine flawlessly. I use a stock version of Mach3 latest lock down with a profile that I set up. I d/led a program called Slic3r form slic3r.org . This program takes stl files and slices the object in the many layers and most importantly produces a G code file compatible with Mach3. Importantly, there are 3 tutorials on 3D printing.
In particular was how to calibrate the extruder steps per unit. This calibration procedure greatly improved the quality of my 3d Prints. Yesterday I printed a hollow ABS duck from a file that I d/led from thingiverse. While the output was perfect it did come out remarkably good. The reason for the problem area were mainly do to the stl file that I d/led. When I ran slic3r it reported that there were manifold errors in the stl file. Manifold errors are holes or gaps in the file thus from the pictures you can see the results in the top view of the printed duck. Considering there was no internal support structure or infill and the walls are only .098" thick, I think it came out very good. Should you decide to use your cnc machine for 3d printing you need to consider the time that it takes to run a part and your machine should have nearly zero backlash and ballscrews.
