Quite recently I set myself a task to print in 3D one object, out of many, from a 3D scene in AutoCAD. How this is, or should be done, left me perplexed for a while. However, I soon realised that this objective is not too difficult a thing to do, like most objectives, once you know what you are doing, or are supposed to be doing! Especially, where in my case, probably like with most 3D printers, the printer's application software accepts 3D models in the .stl or Lithography format. By the way, in case you don't already know, my 3D printer is an UP! Mini 3D Printer.
With this objective in mind, in this blog post I demonstrate how I 3D print AutoCAD models using any 3D printer in general and the UP! Mini 3D printer in particular. Hence, the method should work for any 3D printer software that supports the .stl file format.
The 3D scene I was working on, at the time of setting this objective, can be seen in the Figure above. The orange object in this Figure has been designed to attach a 17 DOF Biped Robot to a Retort Stand. This orange plate is the central character in this scene, which I wanted to print in 3D, the other objects merely have supporting roles. Once I was pleased with the design up to the point where the relative dimensions of the plate and robot's waist bracket (the grey object in the picture above) were just that, relative, the question I asked myself was "How do we go about printing this, what I began to call, the robot attachment plate"?
Here's how I did it.
Firstly, navigate to the Export files menu item in AutoCAD, as shown in item (1) in the Figure above. From there choose the Other Formats option to export the 3D object to another format. An Export Data dialog should pop-up like in item (2) in the image above. Well, it did in my case. This dialog allows one to choose the type of format one wishes to use to save the 3D object(s), as well as provide a file name entry text field and an option to locate the file in any directory. For the exercise let's say I named the file "orange_plate.stl".
I got caught out a number of times at this point thinking that was it and all the models in the current scene had been exported in the new format. Thinking that then led me to try loading the orange_plate.stl file in to the UP application software for printing, but the file did not exist. I was left quite baffled, until it occurred to me that the file "created", in the previous step, could be considered to be empty. It needs to be populated with 3D solids or watertight meshes from the scene before it is committed to the hard drive.
Hence, immediately after providing the file name, in the previous step, the next thing to do is populate it by selecting the 3D object or objects you want to add to the file. In the Figure above, since I only wanted to print the orange plate I placed the mouse over it and selected it by left-clicking on it. I then pressed the enter button to terminate the object selection process and save the selected object in the file named orange_plate.stl.
From this point onwards my description of printing the orange plate is particular to the UP! Mini 3D printer, although similar methods probably apply to other 3D printers. In the UP application software I navigated to the File menu item and selected Open, as can be seen in item (1), in the Figure, above. In the Open dialog that results I navigated to the correct folder and selected the 3D object file (.stl) saved previously.
The orange plate, which had now become a pink one, as can be seen in the Figure above, appeared on the screen. Magic! The dimensions of the object, visually, looked perfect. The UP! Mini had been calibrated previous, thus all I needed to do, to finalise this show, was to select 3D Print from the menu and then click on Print. Approximately three-and-a-half hours later and the final result can be seen in the Figure below, where the orange plate is still attached to the perf or cell board. It has actually been printed in orange , which was not a coincidence, using 1.75mm of ABS plastic. The printed model is 4mm thick.
That's it. In this blog post I have demonstrated how straightforward it is to print a 3D object designed in AutoCAD and printed using the UP Mini 3D printer. It's easy when you know how! In the next post in this category I might demonstrate how to 3D print robot parts, as a separate post, for continuity. For now you can read more about the design process of the 3D orange plate and how it has been used to harness the 17 DOF robot to the retort stand, as seen in the image below, in the blog post Robotics and FPGAs (5) - The 17 DOF Biped Robot Assembly, Part 3 : The Inertial Frame.