Here’s a video to the team from software developer and RepRap expert Alessandro Ranellucci, the creator of the extremely popular Slic3r software.
We made a video to show the difference in noise between the Pololu A4988 Stepper Motor Driver Carrier, which has 1/16 steps, and the DRV8825 Stepper Motor Driver Carrier which has 1/32 steps. These drivers are common in RepRap 3D printers. The resistor soldered onto the DRV8825 is not required on their latest versions of the board.
The goal for this video was originally to capture the difference in sound that I noticed when I switched from one driver to the other, and this test seemed to do that. I updated it to be a bit more scientific than it was originally by carefully setting the current limit, adjusting the steps per unit, and including details about the setup.
For this test:
- 12.17V DC
- Kysan 1124090 (1.8°, 1.5A/phase) stepper motor
- 18T Aluminum GT2 2mm Belt/Pulley
- PLA bushings on W1 tool steel smooth rod with white lithium grease
- 1.3A current limit using VREF method
We’ve learned a lot while implementing our 3D Printer Club project plan at a local elementary school, and in the process, we’ve come up with a number of guidelines and ideas to help you get started doing the same thing in your own school. We’ll use this page as a landing page for resources and information on how to get started. As we add new content, we’ll link to it from here, so please check back from time to time for new articles.
Who Is This For?
Parents, teachers, students, makers, administrators, and more—techie or not. We’ve found that a number of different types of people would like to get started with a project like this, and each one has a slightly different perspective and purpose. While it’s not easy to write a single article for multiple audiences, we’ll try to address these different perspectives throughout. At the end of the day, though, all you really need is time, dedication, and some help from time to time.
What Are We Starting?
First of all, we recommend a project-based approach in a weekly after-school club format—the journey is a big part of the destination here, and an after school club should allow you to pull interested students from a number of grade levels, get a bit more help from parents, and potentially even pull in resources from other schools. The weekly format allows enough time between meetings for individual teams to work independently.
With the help of teachers, parent volunteers, and possibly a couple of older students, the members of the 3D Printer Club will be responsible for researching, documenting, sourcing, building, and operating an open hardware 3D printer. “Open hardware” means that the technology has been developed upon over a period of time by many (possibly hundreds or thousands) or people with a genuine interest in improving and promoting the technology and making it available for the greater good. It’s an organic approach to hardware development, and there are usually no patents or copyrights to contend with. Like Wikipedia is to information, open hardware is to physical technology.
Find a Subject Matter Expert
Some parents or teachers may be perfectly comfortable diving into this project with little or no expertise, but others may feel it’s too far over their heads. In either case, we recommend locating a subject matter expert (SME) to assist you throughout the process. This should be a person—hopefully nearby—with some experience in open hardware 3D printers. Contact a local hackerspace (visit hackerspaces.org to find one) and explain that you need some help with a 3D printer build at a local school.
Hackerspaces are part of the “maker” culture—they are groups of people who like to make or build things themselves, and they will almost certainly have someone with the expertise required and interest required to help with an open hardware 3D printer build. If there is no local hackerspace or if you’re having trouble finding a local SME, contact different hackerspaces in your state or region—most members of the open hardware 3D printer community are willing to help remotely (for example via Skype, email, or chat) as well.
The SME will be a valuable resource throughout the build and will be able to help your team solve problems as they move forward with the build. The SME should also be able to help you arrange demonstrations, or provide access to a reference machine or two to base your build upon.
We got an older laptop to use for one of our 3D printer builds, and so we set out to set it up for 3D printing. The laptop is an IBM ThinkPad T41, and because the processor doesn’t support PAE, we weren’t able to use the latest versions or Ubuntu or Mint. Mint 13 installed okay, but the default window managers gave us some trouble, so we ended up installing Lubuntu 12.04. This version doesn’t require PAE.
After installing and updating the operating system, we set out to install pronterface (Printrun) and slic3r from the git repository. Here’s what we did:
First install python support for printrun, and git.
sudo apt-get install python-serial python-wxgtk2.8 \ python-pyglet python-tk sudo apt-get install git
Create a directory for RepRap stuff, and clone Printrun to it from the git repository.
mkdir RepRap cd RepRap/ git clone https://github.com/kliment/Printrun.git
Next comes build-essential, perl, and cpanminus — all required for slic3r.
sudo apt-get install build-essential libgtk2.0-dev \ libwxgtk2.8-dev libwx-perl libmodule-build-perl \ libnet-dbus-perl sudo apt-get install cpanminus
Go into the Printrun directory, get slic3r, and then dive into that directory where we’ll test it to be sure it all works.
cd Printrun/ git clone http://github.com/alexrj/Slic3r.git cd Slic3r/
Grab the cpan modules required for slic3r, and test it to be sure it loads up properly.
sudo cpanm Boost::Geometry::Utils Math::Clipper \ Math::ConvexHull Math::ConvexHull::MonotoneChain \ Math::Geometry::Voronoi Math::PlanePath Moo Wx ./slic3r.pl
Step up one directory and make sure pronterface works well.
cd .. python ./pronterface.py
In this video, Jacob shows an easy way to make very simple and inexpensive (yet dependable) bare wire end stops for your 3D printer (or other motion control project). This design helps to “demystify the box” by putting all of the switch mechanics in plain view, making it very easy to understand. We’ve had a printer with end stops just like these running without incident for over a year.
Our original “One-Penny Bare Wire End Stop” can be found here, but you can see from the video that we’ve changed the way we do it slightly: http://www.thingiverse.com/thing:23878
Supplies used: Old network cable, paper clip, end stop holder, electrical tape, solder, and about 2 cm of solid copper wire. Tools used: Wire strippers, small triangular file, needle-nose pliers (with wire cutter), ruler, soldering iron or gun, and scissors.
Music: “Crosstalk (Take 3)” by Javolenus, 2013 – Licensed under Creative Commons Attribution Noncommercial (3.0), http://ccmixter.org/files/Javolenus/41845
We went to the Midwest RepRap Festival (MRRF) in March, and Jacob interviewed some experts to learn more about the event, the RepRap project, 3D printing and its future. This video includes a great overview of a delta bot 3D printer, which is pretty new on the RepRap scene.
Music: “December Nights” by cdk, 2011 – Licensed under Creative Commons Attribution (3.0) http://ccmixter.org/files/cdk/34714
This is an SVG file of a Sanguinololu electronics circuit board for 3D printers, and it will likely be helpful if you’re trying to layout a mounting board for your electronics that includes the Sanguinololu and other components. The drawing includes extra space required by connectors or wires that are plugged into it, and the holes have cross-hairs so you can tape it onto a board and easily drill it. (Right-click and Save As to download the SVG. In you need an SVG editor, check out Inkscape—it’s fantastic and free.)
Note that there’s extra space for the USB cable because it tends to be a beefier cable.
Here’s a short video that shows how I make hobbed bolts using an M4 tap, a drill press, and a couple of 608 bearings. If you don’t have a grinder, you can chuck the bolt in the drill press and use a dremel tool or file to cut the groove. The groove gives the tap something to bite into.
Please pardon the focus hunting and lighting—it’s thefirst video with the DSLR. And here’s what especially cool about this video: At about 2:40 you might notice that the bolt is spinning in time with the music… totally unplanned.
Here’s the result. You may notice that I was trying to correct for a slightly off-center grind, so the cut profile looks a bit different on either side.
Music: “Me Robo El Show” by Alex, 2011 – Licensed under Creative Commons Attribution (3.0) http://ccmixter.org/files/AlexBeroza/34167
(BTW: Yes, I’m aware that the lyrics have nothing at all to do with making a hobbed bolt, but this is a great mix of an excellent vocal by Farina, and so I used it anyway.)