Let me just start by saying that this isn't like most "budget" 3D printers. This has all features that a normal one should have; 2 Z axis motors, LCD, and a reliable extruder (Stepstruder MK7). As the title suggests, this project costs less than $200 (USD) to make, with no reused parts. This project took several months to design and about a week of assembling along with trial and error for testing new parts. This printer was built with a Full Spectrum Laser at my local makerspace, along with a Robo 3D printer.
Update: I have sold two 3D printer kits, will be selling the next four in either late May or early June (can't make any promises). I am also selling laser cut acrylic for this at 30 dollars US. Leave a comment if you want laser cut acrylic and I can usually ship within 3 days of payment. You can do so through my new website, down below.
New kit: Everything except 3d printed parts for $220 US comment below if you would like one.
New features: Bigger enclosure to fit all of the wiring, better extruder, built in LCD, Better Y axis belt tensioner, cool looking air vents, less gluing, layered bearing holder for a stable X axis, new logo, faster to laser cut because of fewer joints, more precise measurements for the USB and power connectors and overall better prints.
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Step 1: Print Quality
As you probably know, print quality is a huge aspect when you want to buy or build a 3D printer. The attached image is of an octopus, printed at 250 microns (for speed, can go higher res.) at 35mm/s.
One of the biggest problems of a cartesian 3D printer can be from z wobble. Z wobble is when the coupler that attaches the motor to the threaded rod isn't completely straight. From experience, no 3D printed one will work, unless you have linear rods for both threaded rods. My design only has linear rods for the primary threaded rod, so an all metal rigid one is required. A flexible one will not work properly.
Here is the octopus file: http://www.thingiverse.com/thing:27053/#files
The second image is of a low poly t-rex, printed at 100 microns, which isn't as optimized for the printer. It still turned out quite well.
Step 2: Specs and Info
Resolution: 100 Microns - 300 microns
Speed: 45mm/sec (not yet tested beyond)
Build Volume (X, Y, Z): 145mm x 80mm x 100mm
Overall Printer Size: 100mm x 265mm x 270mm
Threaded Rod: Imperial 5/16 inch, optional metric upgrade
Step 3: Parts and Tools
Here are the parts and tools that you will need to make this project:
Stepstruder MK7 Extruder http://www.aliexpress.com/store/product/0-4mm-Nozz...
RAMPS 1.4 board (includes Arduino mega) http://tinyurl.com/lzozwlw
Nema 17 stepper motors (I bought from Alibaba, so I don't have a link.)
8mm Linear Rod http://tinyurl.com/zbcqt4h
LM8UU Linear Bearing x4 http://tinyurl.com/n98ehwv
Endstops x3 http://tinyurl.com/q47m5cq
3mm acrylic (look for a local plastics shop, or buy pre-laser cut from me, just leave a comment)
16x2 LCD http://tinyurl.com/h8gj979
GT2 Pulley x2 http://tinyurl.com/qc4m6ez
GT2 Belt http://tinyurl.com/nr6wn25
USB B to B Panel Mount Extender http://tinyurl.com/hjp2xvn
DC Power Connector http://www.aliexpress.com/item/1Pc-5-5-mm-x-2-1mm-...
688zz Bearing http://tinyurl.com/zw9c6v9
Threaded Rod 5/16th inch with 5/16 inch nut (can buy at a home depot)
3D Printer wiring pack x5: http://tinyurl.com/o8mont4
608 bearings x1: http://www.aliexpress.com/item/Hot-Sale-1pcs-lot-b...
M3 8mm screws x1 lot of 28: http://tinyurl.com/z8gharl
M3 25mm screws x1 http://tinyurl.com/zgjt2je
M3 10mm screws x20 http://tinyurl.com/gvx642q
Rigid Coupler http://tinyurl.com/z95xhp3
Laser cutter or laser cutting service (Check if there are any local makerspaces nearby)
3D printer or printing service
Soldering Iron and Solder
Computer With Arduino IDE and Cura
Step 4: Laser Cut and 3D Print Files
Use a laser cutter to cut the .SVG out of 3mm acrylic. I cut the parts out a month or two ago at my local makerspace's laser cutter. Download the files here: http://www.thingiverse.com/thing:1291810
If you don't have access to a laser cutter, you can order laser cut parts from me. I charge 30 dollars US, which is much cheaper than any laser cutting service. If you want laser cut acrylic, leave a comment saying so.
Step 5: Mount Ports
Mount USB port and the power jack. Do this by taking the USB B extender and placing it in the rectangular hole on the acrylic side piece and putting the screws through. You can use the images as a reference. Now, to mount the power jack, push the connector through the back piece (the one with "made in canada" on it). Then, thread the corresponding nut onto the power input connector.
Step 6: Wiring
This step is fairly complicated, so use the attached diagram.
*For the Y endstop, wire it to the Y MAX, not Y MIN. For all of the other endstops, wire them to _MIN.
Note: The polarity of the motors doesn't particularly matter as it will just spin the opposite direction, which is easy to fix either by switching the connector, or through the firmware of the printer. Also, the polarity doesn't matter for the heater resistor or the thermistor.
Step 7: Assemble Enclosure
To build the laser cut enclosure, start by taking the top piece (the one with the holes to mount the motors), and placing the front piece (the one with the logo) and placing it on the end of the top piece with the 2 motor mounts. This is now the front of the unit. Parallel to the front piece, place the "back piece", which is the one that is the same as the front, only it has a hole for the power connector and it has "Made in Canada" on it.
Now, place the assembly onto the bottom piece (the one that is like the top one). Finally, place the right piece (one with the rectangular hole) on the right side of the assembly, doing the same with the last piece, just on the left side.
You will need to remove some of the panels during the tutorial, so try to remember where each panel goes.
Step 8: Wire and Mount LCD
In this iteration of the 3D printer, there is a built in LCD for showing the stats of the print, like the temperature. I'm just using a generic 16x2 LCD that you can find for cheap. This step is optional, though I think it is worth the extra 3-5 dollars.
Use the attached wiring diagram to wire the LCD to the RAMPS board. I recommend soldering straight to the pins on the RAMPS board. I just used some super glue to mount the LCD to the acrylic.
Step 9: Assemble X Axis Pt. 1
Mount three stepper motors to the top acrylic piece using M3 5mm bolts. It is a bit more difficult to mount the SC8UU bearings, so I'll use a few pictures along with the instructions. There is a small acrylic piece that has the correct spacing for the bearing (3rd picture). Take this piece and bolt it to the top acrylic plate using M3 5mm bolts and nuts. Now, you can place and bolt the SC8UU bearings onto the top piece because there is support for it underneath. This step is to prevent the bearings from shifting mid print. Finally, you can push 4 bolts through each of the SC8UU bearings, then tightening them with a nut.
Now, use super glue to mount the X endstop to the left side of the top piece. Push the X axis linear rods into the bearings.
Step 10: Assemble X Axis Pt. 2
In this step, we will add the X axis sideplates and the linear rods to the bearing assembly.
Hold the linear rods in the bearings and press fit an X side piece to each side of the rods. Now, push the GT2 pulley onto the shaft of the nema 17 motor and use an allen key to tighten the setscrew in the pulley, making sure that the setscrew pushes into the flat part of the shaft. Next, Take the 3D printed Bearing mount and press fit 2 688zz bearings onto each side of the mount. Finally, use M3 8mm bolts to connect the mount to the motor.
Take about 8 inches of GT2 belt and push about 1/2 an inch through the left side piece and push the belt through the bearing assembly as shown in the last picture. Then, push the GT2 belt through the right sideplate and use hot glue to secure it to the outside of the side piece.
Step 11: Take Apart and Assemble Extruder
The MK7 extruder comes pre-assembled, but you will need to disassemble and add a mount to it. For the extruder mount, there are two halves that bolt together. Take the two 3D printed parts and two M3 20mm bolts and m3 nuts and set them to the side. Remove the lower two bolts at the front of the extruder and then remove the fan and the heatsink. Then, there will be a black injection molded part. Remove the two bolts on that and lift the black piece. Now, place the 3d printed part shown in the 3rd image and place it where the black piece was and replace the black piece on top of the 3d printed part.
Now, Re-assemble the whole extruder. Then, take the other 3D printed extruder mount piece and place 2 LM8UU Bearings into it, then place it onto the other side of the 1st extruder mount piece. Finally, finish the extruder by tightening the two M3 20mm bolts, making sure it goes through both of the 3D printed pieces.
Step 12: Y Axis Pt. 1
The Y axis is one of the most difficult parts of this 3D printer, but I will try my best to explain it in two parts.
Start by taking a 608 ball bearing, a 5/16th inch threaded rod and a 5/16th inch nut placing them to the side. Bend the belt into a loop and put it into the "Y Axis End Cap" and push a 608 ball bearing onto the loop as shown in picture 3. Then, take a 1 1/2 inch piece of 5/16th inch threaded rod and turn a 5/16th inch nut on one side, and place it on the "Y Axis End Cap" as shown in the 3rd image. Finally, tighten it with another nut at the bottom part of the cap. Now, take the end of the belt and push it down into the extruder mount as shown in the fourth image.
Step 13: Y Axis Pt. 2
Take the Y axis and secure a nema 17 motor using M3 8mm screws. Flip over the Y axis motor mount and place a 5/16th inch nut and put it in the octagon-shaped hole. Now, put two LM8UU bearings into the top holes in the mount. Next, attach the GT2 pulley onto the shaft of the motor by tightening the setscrew. Make sure the GT2 belt is at the same height as the pulley. Push the linear rods into the front of the mount and push the extruder mount onto the railing. After that, push the "Y axis Connector" piece onto the rods and following that, the "Y axis End Piece". To finish the Y axis, push the belt down onto the extruder mount.
Step 14: Z Axis
In this step, we assemble the Z axis, which is by far the easiest of all of the axes. To start, take the flexible coupler, and attach it to the motor at the back of the printer. Do the same with the front motor, just instead of the flexible coupler, we will use the rigid one. Use the set screw on the flexible coupler to secure the threaded rod to the coupler. Then use the rigid coupler and secure the threaded rod by tightening the M3 bolts. Place the whole Y axis assembly onto the threaded rods.
Step 15: Power Supply
If you want to use an ATX power supply from an old computer, you will need to make a few modifications. I chose to use a laptop power supply because it is more compact and is silent.
Using a Laptop Power Supply:
If you want to use a laptop power supply that can output 5A at 12V, no modifications are needed and you can just plug it into the printer.
Using an ATX Power Supply:
First, check for a label on the power supply, and look for "Power Good" wire colour. Normally, the wire is green. Take the "Power Good" wire and hook it up to a ground wire. Now, make sure that none of the other wires are touching. Power on the supply and flip the power switch. If you did the first part correctly, the cooling fan will turn on. If you see magic smoke, immediately unplug it and troubleshoot. If it still doesn't work, try with another power supply.
Step 16: Programming Arduino
Downloading the Firmware:
You will need to have the Arduino IDE installed onto your computer. Next, go to GitHub and download the firmware optimized for the printer. Also, if you bought an Arduino other than the one that is linked in the parts list, you should check if it has the cheaper serial chip "CH340g". If it does, you will need to install extra drivers: http://www.driverscape.com/download/usb-serial-ch3... If it is the normal serial chip, you will not need to install any drivers.
Adding the Firmware to the Arduino IDE:
On your computer, Unzip the firmware and rename the folder to "Marlin". Find the "Documents" folder, and find the folder called "Arduino" and open it. Within the Arduino folder, look for the libraries folder and drag the "Marlin" into it.
Uploading the Code:
First, plug a USB cable into the USB port on the 3D printer. Then, open the Arduino IDE and go to File --> Libraries --> Marlin. Once Marlin is open, click "Verify". Once it is finished compiling, press upload. If the code does not compile, leave a comment below and ask for help.
Step 17: Printing...
Here is a video of it printing. My camera battery was dying so the video isn't very long. The first few layers are a raft because the print bed wasn't level.
Step 18: Tuning
To get the best print results, you will have to do a bit of tuning, and there are may ways of doing so.
Y axis shifting: If the Y axis of your printer starts to shift during a print, Check the tension of the Y belt. Make sure that is it tight, but not too tight. Basically, when you push the belt with little force, it should be able to move 1-2mm
In the 1st attached image, you can see the resolution of the printer when the belts aren't completely tight, and when the Z axis threaded rod (the front one) is a bit wobbly. The Z wobble is an easy fix for the most part. To fix it, Make sure that the Z coupler is straight in the centre of both the Threaded rod and the motor shaft. The 2nd picture is when the 2nd Z coupler is perfectly straight (only achievable with a rigid coupler).
As you can see in the 3rd image, I printed a cover for a raspberry pi zero, and it is the right size. You may calibrate the printer if you want slightly better results, but for my printer, it is calibrated well enough.
Step 19: Finished!
Thank you for viewing this instructable! If you liked it, Please like, comment and vote. Also, If you have any questions, please leave a comment down below.
Runner Up in the
Full Spectrum Laser Contest 2016
Runner Up in the
Digital Life 101 Challenge
Second Prize in the
Raspberry Pi Contest 2016