Wow, it took me almost two months to build, but I finally completed building my 3D printer from PrintrBot! Two weeks ago, I put the finishing touches on it by calibrating the motors and attempting to level everything out. [The reason I'm not writing until now is because we've been focused like a laser for the last two weeks on working toward our PLTW program's 5-year re-certification, which we achieved on Friday.]
Along the way, I had to troubleshoot various problems (most of my own making):
- not seeing an asymmetric hole pattern until it was too late
- one misaligned hole
- limit switch wire accidentally torn off
- putting the wrong gear where a pulley-belt system should go
- motors moving in the wrong direction
- a pulley-belt system that was slipping over the motor axle and not moving the extruder along the x-axis the way it should
- incorrectly feeding the plastic material into the extruder
To solve these problems, I used my own engineering knowledge accumulated over the last six years, another teacher’s expertise and tools, and PrintrBot’s online videos and help fora. As mentioned before, I feel that having made these (and many smaller) mistakes and learning how to fix them has really given me a better understanding of the gears, pulleys, bearings, ball screws, nuts/bolts, switches, motors, and wiring that go into making my 3D printer. I also think I have a more concrete understanding of how 3D printing works, and hopefully will be able to fix my printer if it were to break or need improvements.
My First Print
I took (PrintrBot founder) Brook Drumm’s recommendation for my first print, the “Mr. Jaws” shark figure.
The program that runs the printer, Pronterface, estimated that it would take 45 minutes to complete the shark.
On my first try, I had trouble getting the ABS plastic to stick to the printbed, so I increased the bed’s temperature. Here’s some filament that extruded but did not contribute to the shark design:
After a few more minutes of heating up, this time it worked!
Here is the first-layer outline of the shark:
Here you can see that it is starting to fill in the outlines:
And here it is after completing approximately three layers (one filling in the shape up and down, the next left and right, and so on):
I figured I would have some time to grade papers while waiting for the print to finish, but instead I was mesmerized by the printing.
It was also cool to see that the program works using the same G&M codes that I teach my manufacturing engineering students to operate the CNC mill:
It built up slowly, layer by layer.
In thirty minutes, the shark was finished.
You can see some errors, like the strands between fin and tail where the filament turned a corner but the corner didn’t stick. And you can see the granularity of some of the layers is not as fine as on a more expensive 3D printer. But, all in all, for something that cost only a few hundred dollars, and that I built myself, I’m very proud of what it did!