Carnegie Science Center is a popular spot for a play date, where children and adults can experience science first hand. It is also home to a Chevron FabLab, a digital fabrication laboratory for innovation and invention. The Carnegie FabLab holds camps and programs for children 8 – 18. Its mobile lab brings in depth digital fabrication experiences to schools and events.
One of the programs that Carnegie runs is their Teaching Excellence Academy. In November, Sallye Coyle from ShopBot led a session in Digital Fabrication for Educators.
Digital Fabrication for Educators:
ShopBot CNC, Laser cutter, and 3D printer
Date: Thursday, Nov. 17 and Friday, Nov. 18;
9 am – 3 pm daily, with an optional open lab on Friday from 3 – 5 pm
Cost: $200 for two-day workshop
Audience: K—12 teachers and administrators
Fab Lab Carnegie Science Center welcomes Sallye Coyle from ShopBot as a guest educator for this two-day intensive training. For teachers or administrators with digital makerspaces in their schools, or those who are putting together makerspaces, this training is essential. Educators will gain experience with 3D scanning and printing, designing for the laser, vinyl cutter and ShopBot. Participants will be immersed in multi-platform CNC projects, experiencing first-hand the design and engineering cycle used in digital fabrication. With an optional open lab on Friday afternoon, participants will be able to move deeper into creative design for CNC machines and have some fun in the process.
A major focus of the workshop was to show that the work flow is the same for all the digital fabrication tools: use a form of CAD (computer-aided-design) software to get the “what and where” into the computer, set the “how” for the digital fab tool* and look desired, and then let the computer control the machine while it does its work. Since the large format (4’x8’) ShopBot PRSalpha CNC tool is often the most intimidating tool in a lab, we started there. To give everyone a sample of the entire process, we used VCarve Pro, the CAD/CAM software shipped with a ShopBot, to:
- design a sign
- toolpath it to engrave the lettering with a V-Bit
- generate the code for the ShopBot to follow
- set up the ShopBot run the file
Creating the Files
Then it was time for everyone to create their own files. First, the attendees had to measure the size of the various scraps of material they had to work with so they could input the data into the CAD software. Some chose simpler designs with text only, others downloaded bitmaps from the internet and traced them. Toolpathing options included engraving with a V-bit, and using an endmill bit to pocket or to profile along the vectors to cut out the designs. Giving the attendees time to design their own pieces rather than follow a set tutorial is labor intensive for the instructors, but it also allows the attendees to work through their questions while an expert is there to help them. They can also learn from other people’s techniques and mistakes.
While some were waiting for their turn to run their ShopBot project, Steve from Carnegie introduced the laser cutter and vinyl cutter. Using Inkscape, a free graphic software, the group designed a seasonal project that could be cut out of thin wood. Sallye pointed out that the 2D design files (.dxf, .eps, .ai, .svg, etc.) can be transferred into and out of VCarve to other graphic or engineering based CAD programs.
The second day, the attendees worked on bringing 3D designs to life and preparing them for machining on the ShopBot. Since we had a Handibot visiting for the PD and the Camp ShopBot to follow, we decided to machine the 3D files on the little CNC machine. Attendees downloaded 3D files (.stl) from the web that would normally be printed on a 3D printer, and brought them through VCarve to create roughing and finish passes. Here is a link to the blog that describes the technique.
Jon, who runs the Carnegie Mobile Lab, and Liz, FabLab Manager, were intrigued by many of the features of the Handibot. Its resolution is so good that it is the perfect CNC machine for making PCB’s. Since the Handibot uses the same CAD/CAM software as the bigger ShopBots, making a circuit board and making a podium is just a matter of changing the size of the bit and the material. One of the apps for FabMo, Handibot’s Control software, allows children to draw on a touch screen and have it immediately translate to drawing with a pen or carving.
In this Handibot How-To video from August, Brian Owen shows how to cut a custom circuit board:
When Jon asked if the Handibot could be used to cut the cardboard for their Quadcopter project, we grabbed a .0625” bit from the mini mill inventory, imported an Inkscape file into VCarve, and set it to profile to cut through the cardboard. Jon added the motors, soldered in the circuitry, and flew the quadcoptor. He saw potential for using a Handibot rather than a laser to cut the parts on site at a school: easier to transport, no fumes to vent, and more fun for the kids to watch. Cost is a factor, too: 4 Handibots would be cheaper than a single laser cutter.
*The digital fab tools the Carnegie Science Center FabLab has available include two CNC machines (ShopBot and Roland), a laser cutter (Epilog), 3D printers (Ultimaker), vinyl cutter (Roland) and a full electronics station. The Mobile Lab has a ShopBot Buddy with an 110v Desktop spindle, laser cutter (s), 3D printers, vinyl cutter, a mini mill and an electronics station. For those who are unfamiliar with how the various digital fabrication tools work, here is a chart that compares the various tools.