TETRIX 3D-Printer

The TETRIX 3D-Printer was designed as an educational tool for middle and high school technology students, robotics teams, and adults. The purpose of constructing the printer is to train people's building, tool usage, electronics, CAD, and programming skills with a single project. You also get a 3D-printer once you're done!

The printer design is based on TETRIX parts, which are designed by PITSCO and used in the FIRST Tech Challenge robotics competition. The printer also utilizes elements of various RepRap printer designs, such as the Printrboard control system. The design is completely open-source, so feel free to personalize and alter your printer.

The overall cost of the printer is about $640, and the educational value is priceless! The majority of the cost is attributed to the TETRIX parts, but the high accuracy of the pre-drilled, pre-sized aircraft-grade aluminum saves time and reduces error, which outweighs the price.

• Soldering
• Power tool and hand tool usage
• Very simple programming
• CAD designing (Optional)

• Belt Sander
• Hacksaw or BiMetal Band Saw
• Dremel (with cutting wheel and grinding head)
• Hand Drill or Drill Press
• Drill Bits
• Thread Taps
• Cutting Oil
• Reamer
• Caliper
• Transfer Punch
• Center Punch
• Hex Keys
• Screwdriver
• Wrench
• File
• Utility/X-Acto Knife
• Heat Gun
• Crimping Tool
• Wire Stripper
• Soldering Iron (with solder and sponge)
• Laser Cutter (optional)

TETRIX:

• C-Channels
• Inner C-Channel Connectors
• Flat Bars
• Right Angle Bars
• Axle Hubs
• Bronze Bushings
• Nylon Axle Spacers
• Flat Brackets
• Flat Building Plates
• Flat Round Spacers (Instead of Flat Building Plates -- less manufacturing, but more expensive)
• Servo Bearing Set
• Stand-Off Posts (32mm and 2" sizes)
• Hard Point Connectors
• Set Collars

Non-TETRIX Fasteners:

• M3 Screws (18mm)
• M5 Threaded Rod
• M5 Nuts

Raw Materials:

• GT2 Timing Belt
• Springs
• Scotch Painter's Tape
• 1.75mm PLA Filament
• Zip Ties (large and small)

Plastic:

• PTFE Teflon Bowden Tube for 1.75mm Filament
• PETG 1/8" thick

Electronics:

• Laptop power supply (12V, 5A)
• Laptop fans (2 large, 1 small)
• Raw wire (high resistance)
• Sponge (for cleaning soldering iron)
• Solder (Lead-free)
• Crimp heads
• Heating wire (12V)
• Thermistor
• Heating block
• 0.4mm nozzle
• NEMA 17 stepper motors (57 oz and 40 oz)
• Molex Plugs (2, 3, and 4 holes)

SO, WHERE SHOULD YOU GET ALL OF THAT FROM?

• PITSCO
• RP One Labs
  • Heating wire (12V), Thermistor, Heating block, 0.4mm nozzle (pack)
  • Flex Shaft Coupling
  • GT2 20-tooth pulley with 2m of timing belt (pack)
• McMaster-Carr
  • 18mm M3 Screws
  • M5 Threaded Rod
  • M5 Steel Nuts
• Home Depot
  • Scotch Painter's Tape
  • Springs
• RobotDigg
• MicroCenter
  • 1.75mm PLA filament

Smooth Steel Rods:

• 13" (2)
• 2.5"
• 18" (2)
• 16" (2)

Threaded Rods:

• 16" (2)
• 1.75"

Angle Bars:

• 6-hole (2)
• 3-hole (Drilled/Tapped for Stepper Motors) (3)
• 2-hole (5)
• 4-hole (Center Drilled/Tapped)
• 3-hole (Drilled/Tapped between 2nd and 3rd holes)
• 3-hole
• 5-hole (Notch Cut)

Flat Bars

• 2-hole (4)
• 7-hole

Bronze Bushings

1. Secure a bronze bushing into a drill chuck (It helps if you have two hand drills and somebody to help you hold the drill chuck steady)
2. Using a 5 mm drill bit, slowly and carefully enlarge the hole of the bronze bushing. Drill in stages, and clear debris regularly.
3. Repeat to make 4 enlarged bronze bushings.
4. Note: For the other 10 bronze bushings needed, check to make sure that they can slide easily on the smooth rods but are still snug, as this is essential for the accuracy of the printer.

Flat Plates

C-Channels

More details will be available soon.

You Will Need:

Tools:

• 7/64" Hex Key
• 5/16" Open wrench and socket wrench

Parts:

• Kep Nuts
• Short Socket Head Screws (5/16” long 6-32)
• Long Socket Head Screws (1/2” long 6-32)
• Short Button Head Screws
• 416mm C-Channels (x3)
• 288mm C-Channel (x1)
• Tetrix Axle Hubs (x6)
• Tetrix Inside C Connectors (x2)
• Washers (x16)
• Angle Bars (Use the 4-hole ones that you drilled holes into)
• Thin Nylon Spacers (x2)
• Short Standoff Posts (x2)

Assembly:

1. Screw together an inner C-Channel, an axle hub, and a drilled/tapped 4-hole angle bar using long TETRIX screws. The screw heads should be toward the inside of the inner C-Channel, with the the hub flange in the large hole. (Figure 1)
2. Attach a drilled/tapped 4-hole angle bar to the axle hub using the drilled holes. The screw heads should be inside the inside C-Channel. Repeat to make two sets. (Figure 1)
3. Attach the assemblies from Step 1 to the right and left ends of the 288mm C-Channel with the axle hubs and screw heads facing outward. (Figure 1)
4. Lay two of the 416mm C-Channels down parallel to each other, with the open sides facing downward.
5. Place a set of two washers over each of the indicated holes in Figure 2. Repeat on the other C-Channel.
6. Lay a 416mm C-Channel perpendicular to the first two channels, with the open side facing toward you, over the top set of holes with washers. (Figure 2)
7. Lay the 288mm C-Channel from Steps 1&2 perpendicular to the first two channels, with the open side facing toward you, over the bottom set of holes with washers. (Figure 2)
8. Using long Tetrix screws and kep nuts, secure the four channels together with the screw heads facing downward. Tighten using a hex key and wrench.
9. On each end of the 288mm channel, insert the flange of an axle hub into the top side of the channel with the set screw hole facing straight upward. Secure with short Tetrix screws with the screw heads on the inside of the channel.
10. Repeat step 6 on the top 416mm C-Channel.
11. Once the frame is secure, stand it upright. Attach a flat plate and an angle bar as shown in Figure 3, using the 9th and 13th holes from the back of the angle bar.
12. To attach the top screw, insert a short standoff post and a thin nylon spacer inside the C-Channel, using the standoff post as a nut (you may have to pry the channel open). Use a long screw on the other side of the channel to secure the nylon washer and standoff.
13. Repeat Steps 11&12 on the other side of the frame.

You Will Need:

Tools:

• Hex Keys
• Wrench

Parts:

• Constructed Frame
• NEMA 17 Stepper Motor (57 oz)
• Tetrix Screws
• Tetrix Kep Nuts
• Extra Long Tetrix Screws (4)
• 12” Smooth Steel Rods (2)
• GT2 Timing Belt
• GT2 Timing Belt Pulley, 20-Tooth
• 160 mm C-Channels (2)
• Axle Hubs (4)
• Bronze Bushings (4)
• Springs (4)
• 5 mm-Thick Acrylic Sheet
• Glass Plate (optional)
• 2-Hole Flat Bars (4)
• 288 mm Angle Bars (2)
• 2-Hole Angle Bars (4)
• Drilled/Tapped 4-Hole Angle Bars (2)
• Drilled/Tapped 3-Hole Angle Bar (1)
• Lock Nuts (4)
• Washers (24)
• Flat Spacers (4)
• Drilled Flat Spacers (4)
• Plumbing O-rings (4)
• Thin Nylon Spacers (3)
• M3 Washers (3)
• M3 Screws
• M3 Lock Nut (1)
• M3 Nuts (1)
• Short Standoff Posts (5)
• TETRIX Servo Bearings (4)
• Endstop Micro-Switch

Assembly:

Making the sets of flat plates:

• Stack an un-drilled plate on top of a drilled one.
• Place an O-ring inside the drilled hole.
• Insert bronze bushings in the large holes on either side of the C-Channel. Line the stacks up to the bronze bushings, and use extra long screws and short standoff posts inside the channel to tension the assemblies together.
• Repeat on the other end of the C-Channel. (Figures 1-2)

1. Line up the two 160 mm C-channels parallel to each other with the open sides facing downward. They should look like an equal sign. (Figure 3)
2. Attach two axle hubs to the insides of the channels at each end of each channel, on the faces nearest and farthest from you. Make sure the set screws are accessible. (Figure 3)
3. Insert bronze bushings to line up with the axle hubs, with the flanges toward the interior of the “equal sign.”
4. Line up 288 mm angle bars perpendicular to the C-Channels at each end, and place 8 sets of 2 washers underneath the angle bars to elevate them from the C-Channel. Then secure the angle bars to the C-Channels. (Figure 4)
5. At the ends of the angle bars, connect 2-hole angle bars as shown in Figures 4 and 5. They should create a flat surface for the build plate.
6. Lay the cut acrylic plate over the 2-hole angle bars. Mark and drill 9/64” holes to match outermost holes of the 2-hole angle bars. Put the plate aside.
7. In the middle of the top face of each 160 mm C-Channel, loosely attach a pair of stacked 2-hole flat bars. (Figure 4)

8. Attach 2 sets of flat plates to the 288 mm C-Channel on the frame. Use the 5th hole from each end.

9. Use nylon spacers, a 3-hole tapped angle bar, a 20-tooth pulley gear, washers, long M3 screws, and the TETRIX servo bearings to set up the NEMA 17 stepper motor as shown in Figures 8 and 9.

10. Mount the micro-switch to the motor with an M3 screw and a washer, as shown in the bottom left corner of Figure 8.

11. Using the tapped holes of the angle bar, mount the stepper motor onto the center 288 mm C-Channel. The gears should face to the right, and should be aligned with the center of the platform. (The stepper motor should be attached around the 10th large hole from the right end of the 288 mm C-Channel). Figures 6 and 9.

12. Clamp one end of the GT2 timing belt with the two-hole flat plates, as shown in Figure 6. Leave about 1 inch of excess belt. Do not cut the belt yet.

13. Loop the belt around the gears on the stepper motor (Figure 8). Make sure that the belt is stretched tightly.

14. Feed the belt through the Y-Carriage to the other pair of flat plates, and clamp the belt only once you are confident with the positioning and tension (The teeth of the belt crush easily so this cannot be undone). Leave an inch of excess belt, then cut it off of the reel.

More details will be available soon.

You Will Need:

Tools:

• Hex keys
• Wrenches
• Pliers (Flat)

Parts:

• TETRIX Screws
• Kep Nuts
• 416mm C-Channel
• 96mm C-Channels (2)
• 96mm C-Channel with hole cut out of center
• Axle Hubs (5)
• Shaft Collar
• Bronze Bushings (6)
• Thin Nylon Spacers (10)
• Thick Nylon Spacer
• Washers
• Flat Plate Stacks (2)
• GT2 Timing Belt
• GT2 20-tooth Pulley
• NEMA 17 Stepper Motor, 57 oz
• Small Zipties (2)
• 4-Hole Angle Bar w/ Drilled/Tapped Center Hole (Figure 11)
• Notch Cut Angle Bar (Figure 1)
• LEGO Hard-Point Converters (2)
• 18" Smooth Steel Rods

Extruder Head:

• Aluminum Heating Block
• Aluminum Extruder Plate
• PTFE Barrel (Black Plastic Barrel)
• Bronze Pneumatic Straight Fitting
• Teflon Tubing
• 0.4mm Nozzle

• Stainless PTFE Lined Barrel

Assembly:

Vertical Lift Carriage

1. Take a 416mm C-Channel and face its open side away from you.
2. In the middle of the C-Channel, secure a short standoff post and a thin nylon spacer. (Figure 2)
3. Attach flat plate stacks on the 6th hole from the left end, and the 4th hole from the right end. Use Vibra-tite to secure the screws. (Figure 3)
4. Secure hard-point converters to the bottom of the C-Channel at the 3rd hole from the left end, and at the end hole on the right end. (Figure 4)
5. Attach an uncut 96mm C-Channel to either end of the 416mm C-Channel, with stacks of 2 washers in between. The open sides should both face to the left.

6. Attach axle hubs on the right side's 96mm C-Channel. Make sure the set screws are accessible. (Figure 5)

7. Attach axle hubs on the inside of the left 96mm C-channel. Make sure the set screws are accessible. (Figure 6)

8. Attach the notch-cut angle bar using axle hubs on the inside of the left C-Channel channel, spaced away from the channel by a washer’s thickness. (Figures 6-8)

9. Place an axle hub inside the 96mm C-Channel on the right side of the printer. (Figure 9)

10. In the axle hub from Step 6, use 1-2 washers, a large nylon spacer, a bronze bushing, a shaft collar, and the 3” drill rod that you cut to replicate Figure 9.

11. Strengthen the left C-Channel with 2 sets of standoff posts and nylon spacers. (Figure 10)

Extruder Carriage

1. Secure flat plate stacks on the 96mm C-Channel that you cut with a Dremel. Note: The end with more material cut out will now be referred to as the top of the carriage.(Figure 11)
2. Attach an axle hub to the front face of the 96mm C-Channel using the top and bottom holes, with the screw heads on the inside of the channel. (Figure 12)
3. Attach the 4-hole angle bar with a tapped center hole to the axle hub as shown in Figure 12.
4. Loosely attach the aluminum extruder plate using a ¾” screw, 3 washers, a nylon spacer, and a kep nut on each end of the plate, as shown in Figure 12.
5. Wedge the black plastic barrel between the angle bar and the extruder plate by sliding it into the slot in the extruder plate. (Figure 12)
6. Tighten the two ¾” screws on the extruder plate.
7. Screw the bronze pneumatic straight fitting downward into the tapped hole of the angle bar.
8. Screw the aluminum block onto the plastic barrel, with the two holes facing left and right (when viewed from the front). DO NOT OVER-TIGHTEN. (Figure 12)
9. Screw the nozzle and the stainless PTFE lined barrel onto the plastic barrel. DO NOT OVER-TIGHTEN.
10. Cut about 2.5 to 3 feet of Teflon tubing.
11. Carefully insert one end of the tube into the bronze tubing connector. You will need to press on the blue ring in order to insert the Teflon all the way. DO NOT CRUSH THE TEFLON. (Figure 12)

Note: RP One Labs provides further instructions for Steps 5-11.

Putting It All Together:

1. Carefully insert the 18" smooth rods into the axle hubs attached to the right 96mm C-Channel.
2. Sleeve the Extruder Carriage onto the rods through the plate stacks. (Figure 13)
3. Continue inserting the rods until you reach the left C-Channel, then secure all axle hub set screws.
4. Attach a 20-tooth timing belt pulley to a large stepper motor (Figure 14)
5. Connect the stepper motor to the angle bar on the left of the carriage, using long M3 screws and 4 thin nylon spacers. (Figure 14)
6. Attach one end of the GT2 timing belt to the right side of the Extruder Carriage with a small ziptie, as shown in Figure 15.
7. Stretch the belt around the pulley to the right, loop it over the 20-tooth pulley on the stepper motor, then secure it to the left side of the Extruder Carriage. Make sure the belt is tight. You may use pliers, but do not crush the teeth of the belt! (Figures 16-18)
8. Cut excess belt, leaving 1 cm of tail.

You Will Need:

Tools:

• Hex Keys
• 2 Wrenches (Or 1 wrench and 1 pair of pliers)
• Tweezers (Optional)

Parts:

• Flex Coupling (x2)
• NEMA 17 Stepper Motors (40 oz) (x2)
• Cut Threaded Rods (2)
• TETRIX Screws (Socket and Button Head)
• M3 Screws (4)
• Thin Nylon Spacers (4)
• Enlarged Bronze Bushings (4)
• TETRIX Lock Nuts (4)
• M5 Nuts (2)
• Drilled Out M5 Nuts (2)
• 16" Smooth Rods (x2)
• 3-Hole Flat Bar w/ Tapped End Hole
• 1.75" Threaded Rod

Assembly:

1. With M3 screws and thin nylon spacers, attach 2 small stepper motors to the angle bars on the bottom of the frame. (Figure 1)
2. Attach a flex coupling to each stepper motor. (Figure 1)
3. Slide the 16" smooth rods through the axle hubs at the top of the frame, through the plate stacks, and into the lower axle hubs. Tighten all set screws.
4. Insert 2 enlarged bronze bushings in the top of the X-carriage's long C-Channel, at the outermost right hole, and the 3rd hole from the left. (Figures 2-3)
5. Insert 2 enlarged bronze bushings in the 2nd hole from each end of the frame's top C-Channel. (Figures 4-5)
6. Sleeve the threaded rods through the bronze bushings in the top of the frame, and through the X-Carriage's bronze bushings (The X-Carriage should not be centered).
7. Stack a drilled and an un-drilled M5 nut together. Carefully slide the stack into the center of a hard-point converter. Repeat on the other side. It does not matter which nut is on top, as long as you remain consistent between the two sides. (Figure 6)
8. Carefully screw the threaded rod into the hard-point converter, and into the flex coupling. Tighten the set screw of the flex coupling. Repeat on the other side.
9. Screw one M5 nut onto the top end of the threaded rod, and tighten it onto the bronze bushing. Then screw another M5 nut on top of it to lock the rod in place. Repeat on the other side.
10. Use a short TETRIX Screw and a TETRIX lock nut to lock each bronze bushing down on the X-Carriage. (Figure)
11. On the

More details will be available soon.

Pre-Made Extruder Alternatives:

1, 2

You Will Need:

Tools:

• Bandsaw
• Heat Gun
• Drill
• 9/64” Drill Bit
• Hex Keys
• Wrench
• Sharpie Marker

Parts:

• TETRIX Socket Head Screws
• PETG Plastic
• Large Computer Fans, 12V 2.0A (x2)
• Optional:
• Packing Tape
• Cardstock
• Small Computer Fan, 12V

Assembly:

NOTE: Dimensions may vary depending on what size fan you are using.

1. Cut out two 4.75” by 6.5” rectangles of PETG plastic.
2. Place the two large computer fans on the table, with the grille side down.
3. Lay the PETG on top of each fan, aligning the fans as shown in Figure 1. Note: The two sides will not be identical; they should be mirror images of each other.
4. Trace the edge of the fan onto the plastic with a permanent marker.
5. Mark the screw holes of the fan onto the plastic.
6. Trace a square within the screw holes, leaving enough room for drilling error.
7. Using a 9/64” drill bit, drill out the screw holes that you previously marked in Step 5.
8. With a bandsaw, cut out the square from Step 6.
9. Draw a dotted line ¾” from the side edge of the plastic with a permanent marker.
10. Stand the plastic vertically on an angle bar (Figure 2) and mark two holes on the plastic. These holes will be used to attach the plastic to the frame, so make sure they line up to the angle bar’s holes. Do not allow the holes to cross over the line you marked in Step 10.
11. Drill the two holes out for each piece of plastic, as well as another hole toward the lower edge of the plastic. (Figure 2)
12. Attach the plastic plates to both sides of the printer.
13. Use a heat gun to create a 90-degree bend along the line marked in Step 10. Use the heat gun to flex the plastic away from the platform as well.
14. Attach the fans to the plastic sheets.
15. Optional: Attach a smaller fan to the large C-Channel of the X-Axis Lift Carriage. Use tape, cardstock, etc. to direct the airflow toward the center of the build platform. (Figure 3)
    

You Will Need:

Tools:

• Hex Keys
• Wrench
• Pliers (Optional)

Parts:

• 7-Hole Flat Bar
• 5-Hole Angle Bar
• M3 Screws (3)
• M3 Lock Nuts (3)
• M3 Nuts (2)
• TETRIX Servo Bearings (2)
• TETRIX Metal Servo Horn
• 3/4" Socket Head Screw
• Thin Nylon Spacers (3)
• Kep Nut

Assembly:

• Attach the 5-hole angle bar to the feet of the frame as shown in Figure 1, using 2 M3 screws, 2 M3 lock nuts, 2 servo bearings, and 2 M3 nuts.
• Attach the 7-hole flat bar as shown in Figure 2, using the 3/4" socket head screw and 2 nylon spacers. The bar should line up with the 13th hole up from the base of the vertical 416mm C-Channel, which will be the 3rd hole beneath the bottom standoff post of the extruder.
• On the 3rd hole from the far end of the flat bar, attach a servo horn and a nylon spacer with an M3 screw and an M3 lock nut. (Figure 3)

Printrboard:

1. Cut a piece of PETG plastic according to the dimensions in Figure 1.
2. Drill 3-4 holes that line up with the holes on the left vertical C-Channel of the frame, and attach the plastic to the frame with washers, nylon spacers, TETRIX screws, and kep nuts.
3. Find a space toward the bottom of the plastic for the Printrboard, but leave 1.5 inches of plastic empty at the bottom. That space will be used later for installing the power plug.
4. Drill holes to line up with the holes on the Printrboard.
5. Mount the Printrboard upside down (Red button at top), using TETRIX screws, nylon spacers, and kep nuts, as shown in Figure 2.

Stepper Motors:

1. Attach the provided plug/wire to the stepper motor.
2. Strip the ends of the provided wires and the ends of different-colored raw wires by about 1 cm.
3. Twist the frayed ends together tightly. For the two Z stepper motors, twist the same-colored wires from the provided motor wires together before twisting them into the raw wires. This will tether them electrically and enable them to move in sync.
4. Solder the wires together and wrap the area tightly with Kapton tape. The tape should cover 1-2 cm on either side of the joint.
5. Trace the wires along the frame and underneath the build platform in order to reach the Printrboard. Tuck the wires into C-Channels whenever possible, but do NOT thread them through any holes. Give the wires 2-3 inches of slack.
6. Cut, strip, and tin the ends of the traced wires.
7. Using a crimping tool, add crimp heads to the end of each wire.
8. Insert the wires into the 4-port Molex plug. (Make sure that the small tab on the end of the crimp head is sticking up before you insert it into the plug; you should hear a soft click when it seats properly.
9. Plug the wires into the Printrboard as shown in Figure 5, giving about 1" of slack for each wire.
10. Bundle the excess together, and ziptie it within the bottom C-Channel of the frame.

More details will be available soon.

Printer Firmware

Download Arduino 1.0.5 and the Marlin firmware (altered by Lincomatic for the Printrboard here). Follow Lincomatic's and RepRap's instructions for installing the firmware through Arduino.

Note: the BOOT jumper is a small removable plug that is placed over two pins. Do not lose it!

Once you have Marlin installed, open the file "Marlin_i3_LCD_EPCOS.ino" and click on the "Configuration.h" tab. Scroll down to the "#define X_MAX_LENGTH"

Set X_MAX_LENGTH to 225, Y_MAX_LENGTH to 130, and Z_MAX_LENGTH to 190.

Printing Software

I use Cura 14.12.1 as a slicing and printing engine. More recent versions under Generation 15 seem to be more locked down to Ultimakers, so I recommend downloading a Cura 14 software. You can find all versions here.

Another easier program for controlling the printer is Pronterface, which is a subsection of Printrun (download here). This only controls the motions of the printer, so you will have to download a GCode converting program (I recommend ReplicatorG) and a slicing program (Slicr).

My preferred setup uses Cura for general printing, and Pronterface for controlling the printer during calibration.

You can use any CAD software for designing things to print, just export your design as an STL file before loading it into your slicer engine. You can also use Thingiverse to download fun designs to print out.

See the above images for the general Cura printing settings for the TETRIX Printer. You can adjust these settings to fit your needs.

Start and End GCodes (Copy/Paste into Cura):

Start:

;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}<br>;Print time: {print_time}
;Filament used: {filament_amount}m {filament_weight}g
;Filament cost: {filament_cost}
;M190 S{print_bed_temperature} ;Uncomment to add your own bed temperature line
;M109 S{print_temperature} ;Uncomment to add your own temperature line
G21        ;metric values
G90        ;absolute positioning
M82        ;set extruder to absolute mode
M107       ;start with the fan off
G28 X0 Y0  ;move X/Y to min endstops
G28 Z0     ;move Z to min endstops
G1 Z15.0 F{travel_speed} ;move the platform down 15mm
G92 E0                  ;zero the extruded length
G1 F200 E10              ;extrude 3mm of feed stock
G92 E0                  ;zero the extruded length again
G1 F{travel_speed}
;Put printing message on LCD screen
M117 Printing...

End:

M104 S0                     ;extruder heater off<br>M140 S0                     ;heated bed heater off (if you have it)
G91                                    ;relative positioning
G1 E-1 F300                            ;retract the filament a bit before lifting the nozzle, to release some of the pressure
G1 Z+0.5 E-5 X-20 Y-20 F{travel_speed} ;move Z up a bit and retract filament even more
G28 X0 Y130                              ;move X/Y to min endstops, so the head is out of the way
M84                         ;steppers off
G90                         ;absolute positioning
;{profile_string}

First Prints:

Note: You can use these print files at any time, in order to calibrate and improve your printer settings.

Calibration Box and Tower (Use a caliper to measure how accurate the sizing of the box is. Observe the vertical wobble in the tower's walls.)

Robot (Pay attention to the detail on the front, the spacing between the antennae, and overhangs. You will then be able to adjust extrusion rate, speed, retraction, and fan settings based on your observations.)

Modifications:

The Z-axis motion of the printer will be fairly shaky in the beginning. After running calibration prints, use these designs to print Z-axis stabilizers. They will attach to the X-axis lift carriage, and hook around the vertical TETRIX beams of the frame.

The filament may slip off of the gear track of the extruder, so print this design to keep the filament from shifting and sliding.