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    3D printers, often called Rapid Prototype Machines, have been around for a very long time. Until the early 2000s, they were priced well out of range for most schools and individuals. In 2004, the RepRap open-source movement was launched where the electronics, plans, and materials for constructing 3D printers brought the world of 3D printer within reach of everyone. 

    The RepRap community supports dozens of printer designs with individuals creating new models all the time. High quality printers can now be constructed for as little as a few hundred dollars using open-source software to design models, create the G-code files, and run the machines. 3D printers are capable of printing many of their own parts! Below is a list of helpful resources designed to assist those with a desire to try this innovative technology. 
     
    Printer Sources:
    Whether you want to build your own printer from scratch or purchase a kit, here are some reliable resources:
     
    The official RepRap website with plans and all the information you need to build and use a 3D printer.
     
    While there are many vendors out there selling inexpensive kits, this Ebay vendor, Chowhe Electronics, has done well for us. We have purchased 3 complete Prusa i3 kits and 2 Kossel kits from them and the electronics to refurbish our older Rapman 3.1 printer. Shipping is quick and they always answer questions quickly. 
     
    Controller Software:
    The 3D printer needs special software to control the machine and convert the G-Code file generated from your model into machine code. RepRap printers mostly work using the Arduino open-source electronics system. Our printers use the standard 3D printer electronics Arduino Mega 2560 circuitry. There are two parts to this system: the firmware that is copied to the printer that runs the machine and the Arduino software that reads the firmware, allows you to modify the code for your machine, and uploads the firmware to your machine. 
     
    This is the website for downloading the software. 
     
    Marlin is a popular firmware used to run the 3D printer. Specific Marlin files can be found under each printer to the right. This link discusses the various settings.  
     
    A program that can be used to directly control your printer from a computer.
     
    Slicing Software:
    After making your 3D model, you will need a program to slice the model and create the G-code file. 
     
    Slic3r is our program of choice for creating our G-code file because of it's reliability, flexibility, and ease of use. 
     
    3D Modeling Software:
    You will need software to make your 3D models. While there are many purchased programs out there that work great like AutoCAD and SolidWorks, there are also free alternatives.
     
    Blender is a free open-source 3D design & animation program that can be used to build elaborate 3D models. It also contains a plug-in for 3D printing analysis. 
     
    Sketchup is a free modeling tool originally developed by Google. A great place to also find 3D models to download.  
     
    Sources for 3D Models: 
    If you would like to find a 3D model on the web, there are several sources.
     
    A community site where users post 3D printable models. 
     
     
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    The RepRap Prusa Mendel i3 (iteration 3) is our second 3D printer in the lab. The complete kit cost about $350 from an Ebay vendor (Chowhe Electronics) and included a display screen with SD card reader. This allows the machine to run as a standalone with no need to be connected to a computer. 
    Prusa  
     
    These are the basic build instruction for the Prusa i3. The actual kit has been improved in several areas which means some of the steps will need to be modified from these plans. While these changes will require a little thought, the plans are still very useful. 
     
    Here is the modified firmware for the Prusa i3. These settings work well for our machine. You may need to modify a few of the settings if your model differs. Use the Marlin Firmware link to the left for assistance.  
     
     
    Construction Notes:
    Be prepared to research, ask questions, and learn a lot through the construction process. Construction and calibration of a 3D printer can take 30-40 hours. Here is an STL file that can be printed to house the display screen, as seen in this video. The file: Screen Case File
     
    Helpful Diagrams:
    Here are a few helpful diagrams for wiring the circuitry.
     
    ArduinoMega  
    The above diagram displays the connections and settings for the Arduino RAMPS 1.4 circuitry.
     
    RAMPSWiring  
    The above diagram displays the wiring to the Arduino Ramps board to all printer components.
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    We purchased our first 3D printer kit in 2010 from Bits from Bytes. The kit cost about $2,000 and included dual extruder heads. It was a slow machine with lots of moving parts. This machine, the RapMan 3.1, is based off of RepRap's very first printer design, the Darwin, which is now considered an obsolete design. While considered a dual extruder machine, it could never print in 2-colors due to the inadequate hardware and power supply design. The machine worked well for about 4 years. At that time, the electronics and extruders began to fail. After building the Prusa i3, we saw an opportunity to rebuild the RapMan using the same Arduino Mega 2560 electronics system and re-engineering the extruder assembly to make a true 2-color printer. 
     
    RapMan  
     
    Here is the modified firmware for the Rapman printer. These settings work well for the newly modified system. 
     
    The entire extruder carriage was re-designed for the printer and those parts were printed on the 3D printer.
     NewCarriage
    The only parts that were reused were the extruder stepper motors. All part designs are available on Thingiverse for download so you can print your own.
      
     
    Construction Notes:
    If you have an old Rapman 3.1 and wish to try these modifications, please refer to all construction notes found up on Thingiverse. This project presented a few challenges, but is proving to be working well. A few of the challenges included moving the X-axis belt slightly, switch from 3 mm filament to 1.75 mm filament,  and finding small fans for the new extruder layout. 
     
    The electronics we used for the modification were purchased from Chowhe Electronics on Ebay. It was a complete Arduino Mega 2560 with RAMPS 1.4 and display screen with SD card reader. We also added a MK3 heated bed to allow for better builds.  We reused all stepper motors. 
     
    Here is a handout my students use in the lab to help them setup and print on the 3D printers. 
     
     Kossel Mini Kit
     
     
    Early in 2016, we were able to purchase 2 Kossel Mini printers (one for each high school) with a grant from the Panther-Ram Foundation. These kits were purchased from the same vendor as our Prusa i3 listed above. The kits were of good quality and went together well. The students enjoyed seeing it built and one student was actually inspired to purchase a kit for himself. 
     
    As with the other kits, there were a few parts we needed to design and print ourselves, such as an LCD screen case, electronics mount/cover, and a few brackets. These designs have been posted on Thingiverse HERE.
     
    There are many examples of the Marlin firmware on the internet that can all work well with a few setting changes that need to be made specific to your build. 
     
    A video of the project can be found on YouTube that details the project: https://www.youtube.com/watch?v=Yg8C3U2arPI
     
    And thanks again to the Panther-Ram Foundation for making this purchase possible! 
     
    Kossel
     
     PETE&C 2016 Presentation
    3D Printers Hard to Build? Maybe Not!
     
    Here is the PowerPoint presentation from the session:  PETE&C 3D Printer Presentation
     
     
     
     
     
    contact: jchronister@cdschools.org