Velleman K8200 3D Printer Kit –
Last month, I wrote about the challenges and lessons I learned from building the Velleman K8200 3D Printer Kit. As it turns out, the setup and calibration was way more fun than the build.
The printer can be a bit rough around the edges, but by the time you have everything tuned the way you like it, you will have learned a great deal about how your machine works. The Velleman K8200 3D printer has very customizable settings, with the trade off that they are not all changeable within the provided easy-to-use interface.
3D printers take a 3D model, usually an .stl file, and use "slicer" software to divide the model into printable layers. From there, a g-code is constructed to command the printer to execute the geometric movements (x, y, z axis) necessary to print the part. The supported software, Repetier, is a nice, free interface that handles the g-code for you. Repetier also handles the slicer software pretty well within the same interface, making the process relatively user-friendly.
The kit's instruction manual will give you the correct settings to use for your first print, which are not default settings. All of the other settings must be changed in a separate file meant to specify your printing material. This file is essentially a text file that the printer will use for parameters such as the fill density, infill shapes and number of shell layers.
You start the calibration by tuning the motors to a standard voltage – but there was a step left out of the instructions about when to plug in the power cord. Remember to plug in the power cord just before tuning the motors, because you will not get correct readings or enough power from just the USB connection.
I began to calibrate the printer bed and all of its "home" positions on the x-, y- and z-axis when I encountered a small clearance issue. The black home switch pictured figure 1 was blocking the extruder assembly from reaching the bottom of its range and activating the switch.
When I hit the z-axis home button in Repetier, the assembly ran into the switch housing and caused a very loud vibration as the motor kept trying to turn but could not. While I tried to figure out what was going on, a couple of co-workers walked into the room to see if I broke something. I used a washer to resolve this clearance issue and was back in business. Aside from embarrassing myself, there were no other problems caused by the clearance issue.
The next step before printing your first part is to feed your filament through the extruder. I recommend purchasing your own filament as you will likely want to start testing out what your printer can do and maybe try out more than one color. Once you get your full-sized spool primed as per the instructions, you are ready to print!
Your first print will let you know what to adjust in your printer profile text file. In our case, we could tell we needed to increase the filament retraction because PLA filament was unintentionally dripping when the extruder was moving between sections where it actually needed to lay down material (as can be seen between the Christmas tree branches in figure 3). The extra material on the first print was cleaned up a bit with a precision blade. Each of these tree halves were printed in about 20 minutes and without bugging any of my co-workers in the other room. This printer is surprisingly quiet, even with the fan turned on all the way.
Now that you know what to expect from the build, calibration and printing – build your own 3D printer.
Ben earned his bachelor's degree in Mechanical Engineering from UC San Diego, where he learned about robotics and electric vehicles. Originally from Monterey, CA, Ben currently lives in the Bay Area where he works with the Product Marketing team at Jameco Electronics. His interests include innovative technology, music, tools and anything automotive.