Have you ever wanted to build your own 3D printer but felt like you didn’t know where to start? This tutorial is the perfect starting point for any beginner in the field of 3D printing. This will be a detailed account of how to create a DIY RepRap 3D printer. RepRap stands for “Replication Rapid-Prototyper” and it generally describes a printer that can be used to create parts for continuous improvement. I will begin with the physical build and continue into the coding and electronic components aspect in subsequent tutorials.
Final printer specs:
Desktop Footprint: 11in x 13in x 13in
Maximum Build Space: 5.5in x 4.5in x 5in
The list below shows the exact materials used in this tutorial. Components can be switched out depending on your preference, however, it will change the necessary dimensions of some parts. The fabricated wooden parts will also have accompanying CAD models for ease of fabrication.
Plastic milk crate, 11in x 13in x 13in
3D Printing filament PLA
5 m GT2 timing belt, cut to size
4x GT2 5mm bore timing pulley
4 x Diameter 8mm Linear Round Shaft
4 x NEMA 17 Stepper Motor
Signstek 3D Printer MK2 8 x 8 mm glass plate
2 x Thread Screw TOOGOO(R) 3D Printer 8mm Lead Screw Rod Z Axis Linear Rail Bar Shaft 400mm
2 x TriGorilla Silver Tone SHF10 10mm Linear Rod Rail Shaft Support for 3D Printer
1 x MK8 Metal Extruder for RepRap 3D Printer 1.75mm Filament 0.4mm Nozzle 12V 40W Heater NTC3950 Thermistor
4 x BQLZR SCS8UU Linear Motion Ball Bearing CNC Slide Bushing 34.5mm Length
2 x TriGorilla 3D Printer Accessories 5mm to 8mm Blue Aluminum Alloy Motor Shaft Coupler Coupling Connector
16 x M4-0.7 x 16 mm machine screws
8 x #8 x 2 in screws
4 x #8 x ½ in screws
4 x M6-1 x 25 mm screws
4 x M6-1 flange nuts
4 x 608ZZ rotational bearings
2 x 5/16th 3 in screws
4 x 5/16th nuts
6 x 1 ½ in diameter 5/16th bore washers
8 x 1 in diameter 5/16th bore washers
4 x 4 cm x 3.5 cm x 2 cm 8mm bore wood blocks (linear guides)
2 x 13.5 in x 3 in x 0.25 in wooden plates (top plates)
2 x 2.5 in x 1.5 in x 0.75 in wooden blocks (linear plates)
4 in x 1.5 in x 0.5 in wooden blocks (extruder sled)
12.5 in x 7.5 in x 0.5 in wooden plate (build plate support)
The idea of a 3D printer has been floating around since the 1970s. However, until recently, 3D printing technology had not been commercialized or made available for personal use. Now, it’s entirely possible for an average hobbyist to construct their very own 3D printer. However, there is still an equipment gap to bridge. Most 3D printer kits and RepRap printer tutorials assume that the user already has access to a 3D printer. This seemed redundant to me, and therefore, I sought to design a printer that did not require any 3D printer parts to function. The intention of this printer was to introduce beginners to printing and allow them to create a printer, which they could continuously improve from this point on.
The first step in the design process was finding the most straightforward printer design for beginners to follow. As such, I used the Maker Mendel and many RepRap printers as inspiration for a box-shaped printer. The extruder would then move in the X and Y directions while the bed moved in the Z direction.
For ease of use and stability, I decided to use a milk crate base with wooden parts that could be swapped for 3D printed parts later. Then, I choose the corexy belt configuration in order to familiarize beginners with the popular belt configuration and to ensure the base design was efficient. Finally, the RAMPS controller was chosen for its ability to interface with Arduino and its overwhelming popularity within the RepRap community.
Figure 5: Components needed for constructing the top plates
3) Using the two steppers, mark mounting hole positions on one top plate near each corner. Drill mount holes using 7/64 in drill bit. Drill center stepper shaft hole using 3/8 in drill bit. Connect the steppers to the top plate using the M4 screws.
Figure 6: Top view showing the steppers Mounted In position on one side of the top plate
4) On the other top plate, mark holes for the bearings and screws near each corner. Drill the hole using 5/16 in drill bit. Insert the 5/16 in screws into this hole. Add these parts in order: a 5/16in nut, a 3in washer, a 1.5in washer, a bearing, a 1.5in washer, a 3in washer, a 1.5in washer, a bearing, a 1.5in washer, a 3in washer, and a 5/16in nut. These parts will serve as guides for the belts.
Figure 7: A side view of the belt guiding mechanism assembled in step 4
5) On both top plates, mark the center of the board. Place the center of the linear shaft support on this mark and designate the hole placement for its other two holes. Drill these three holes. Connect the linear shaft support with the M6-1 screws and M-1 nuts.
Figure 8: Top View of Z axis guide that was connected to the top plate in step 5
6) Place the linear guide blocks against the stepper motor and line it up with the outer edge of the motor. Make sure the hole in the block is facing the other top plate, not the other stepper. Use a clamp to hold it in place. Use the #8 x 2 in. screws to connect the two. Repeat the step for the other stepper motor, as well as the other top plate. Place the blocks just within the plate boundaries.
Figure 9: Picture showing fully assembled top plates
Step 2: Build Linear Sleds
1) Cut the linear rods to size. For this tutorial, the middle rods were 260 mm and the side rods were 250 mm in lengths. Slide the side linear rods into the blocks you connected in the last step of Step 1. These rods will be your y-axis.
2) Take the linear plate blocks. Place a linear bearing on top of each block and mark where the holes must go. Drill those holes with the 7/64 in. drill bit. Insert the M4-0.7 screws to hold the linear bearings in place. Mark holes in the thinnest section of the block 1 5/8 in. apart. Drill two 8 mm holes. Place the middle linear rods in these holes. These rods will be your x axis.
Flip over the block so that the linear bearing is on the bottom. Stack two timing pulleys in the center between the mounting holes for the linear bearing. Place a #8 x 2 in. screw through the timing pulleys. Use a screwdriver to secure them to the wood block. Make sure they can still spin freely.
Figure 11: Side view of fully assembled linear sled
Figure 12: Top View of fully assembled linear sleds
These blocks allow your extruder to move along the y-axis.
3) Slide the blocks onto your side linear rods.
Figure 13: Bottom view of X-Y sliding mechanism and hex key
Step 3: Build Extruder Sled
1) Take the extruder sled block. Place two linear bearings on the middle linear rods. Press the extruder sled block against them in order to see how far apart the linear bearings need to be. Mark where the linear bearings sit and where the holes should be. Drill these holes using a 7/64-in drill bit. Drill the top of the block again with a much larger drill bit (e.g., 3/8-in) to countersink each hole. Secure the linear bearings with M4-0.7 screws into all eight holes.
2) Mark the middle of the block, 1/2-in from the linear bearings. Drill these holes with the 11/32-in drill bit. See fully assembled part in Figure 13.
3) Place command strips against the middle of four countersunk holes. Press the Extruder against the strips and hold for 30 seconds. Thread zip ties through the holes on either side of the linear bearings to hold the extruder in place. This setup will allow you to remove and/or upgrade the extruder with ease if needed.
Figure 14: Fully assembled extruder sled
Step 4: Build Extruder
1) The extruder should come with a thermistor (Figure 15) which measures temperature, a heating element (Figure 16), and an extruder head (Figure 17). The thermistor and heating element both go into holes on the extruder head as shown in Figure 17.
Figure 15: Thermistor that comes with Extruder
Figure 16: Heater that comes with Extruder
Figure 17: Hot end with holes labeled
2) Use electrical tape to bundle all the wires together and move them away from the printer mechanisms. Screw the extruder head into the main body of the extruder using the hole labeled in Figure 18.
Figure 18: Extruder with hole labeled for hot end
3) Press rubber tube for filament into the extruder body.
Figure 19: Fully Assembled Extruder with sled
Step 5: Build Z-axis
1) Take the build plate support block. Mark the block on either side in the center, 2 cm from the longest edge. Drill the hole with the 11/32-in drill bit. Push the nuts from the thread screws through each hole. It should be a tight friction fit. For added stability, use #8 1/2-in screws to secure the nut.
Figure 20: Plate support
2) Place the shaft couplers on the two remaining stepper motors and use a hex key to tighten them as appropriate. Place the thread screws in the other end of the shaft couplers and tighten them again. Use Zip ties to secure the stepper motors to the bottom of the milk crate.
Figure 21: Stepper with shaft coupler attached
3) Place the build plate support on the thread screws and twist the screws to lower the plate. Slide the top plates over the thread rods to make sure everything is in place.
Step 6: Finishing touches
1) Use Command strips to adhere the glass build plate to the wooden support. This will allow easy removal of the build plate.
Figure 22: Glass Plate Adhered to Wooden Support Plate
You may also need to sand certain parts in order to get the full range of motion.
Part 1 covered the physical build of the printer. We began by overviewing our design. Then, we cut out the wooden parts and connected the necessary hardware to each piece. All electronics and coding as well as setting up the belts will be covered in Part 2.