ScrapRap: $50 3D Printer (Final Product)




I built this printer out of completely salvaged materials from dot matrix printers, scanners, and scrap wood. The only things purchased were the hot end, threaded rod, and the ramps board.

I am a high school student on a tight budget, so the goal of this project was to bring 3D printers to anyone willing to put their mind to building one. The final cost of my printer was $47, and a lot of time.

Step 1: Tear Apart Some Printers

From three printers, I was able to salvage:
4x nema 17 stepper motors*
4x 8mm linear rails
4x 8mm bushings
2x timing belts
2x gears for motors

(I also plan to build a filament extruder to recycle all of the injection molded parts from the printers.)

*A general rule is that you are most likely to find stepper motors in older printers.

Step 2: Other Materials

I was also able to pull 8 bearings out of an old pair of roller blades. After soaking them in WD40, they spin great.

You will also need:

- various pieces of scrap wood

- old USB cables, or other scrap wire

- screws

- bolts

- ramps board 1.4 (purchased from ebay for $20)

- hot end (purchased from ebay for $12)

- wood glue

- epoxy

Step 3: Tools

You will need:

- drill with various bit sizes

- hand or miter saw

- screw drivers

- table saw (optional, but helpful)

- drill press

- clamps

- soldering iron (and materials)

- creativity

Step 4: Assemble X and Z Axes

1. Glue the parts for the ends of the X carriage to the Z axis nut holder.

2. You should now have two parts that look like the third picture. Now glue nuts in each of the holes.

3. Glue the bushings into the other block. This will later be used to hold the extruder.

4. Take two of your 8mm rods and put them into the holes of one end.

5. Place the extruder carriage on the rods.

6. Put on the other end.

7. Cut a 36in threaded rod in half to get two 18in pieces.These will make the Z axis.

Step 5: Y Axis and Base

1. Cut a piece of plywood to the length and width of your linear rods.

2. Cut two 1x4s to the width of your x axis as shown in picture 2.

3. Drill holes to allow for the smooth rods in the 1x4s.

4. Make another piece out of a 1x4, but put bushings in it instead. This will be the platform for the printbed.

5. Glue and screw both ends onto the plywood.

6. Insert the smooth rods into the base, along with the bed platform as shown in picture 5.

7. Glue on the back bearings for the timing belt.

8. Attach the stepper motor to the front of the base.

Notice: I had to cut the groove all the way down so my belt would fit under the platform.

Step 6: Finish Z Axis

To attach the Z axis motors to the base, I had to use 4 pieces of wood because I did not have screws long enough. I first attached the motors to thin pieces of mdf, which were then screwed to the longer supports that connect to the base. I then attached the motors to either side of the base with the correct spacing to attach the X axis assembly.

Step 7: Build the Bed

1. To start off, cut a 10x10 square of glass and cover it in painters' tape.

2. Make the nylon bushings by drilling a 5/16 in hole into each piece, then cut them in half.

3. Make screw holes in either side of the bearings to allow for the tension to be adjusted.

4. Then attach the bushings to a cross beam to connect them together.

5. Cut two 12x10in pieces of plywood out to form the bed platform.

6. Screw one piece to the bushing. Attach the other with a screw in each corner to the one below. This allows the bed to be trammed (leveled).

8. Drill three holes in the top to allow access to the screws below.

9. Attach the bed to the base by inserting the 8 mm rods into the nylon bushings.

10. Connect the bed to a timing belt and loop it around the stepper motor.

Step 8: Put It All Together

1. The X axis assembly is then connected to the base using the couplings on the threaded rod.

2. Build a box around the X axis assembly to provide support to the printer.

3. Connect the hot end to the X axis using an L shaped piece of sheet metal.

4. Use PTFE (Teflon) tube to connect the extruder to the hot end.

5. Bend a short length of copper pipe into an inverse h shape to hold a spool of filament.

Step 9: Extruder

For the extruder, I decided to use a bowden style, however I adapted it to use only hand made parts.

1. To start, attach the motor and gear to a piece of mdf.

2. Cut out a piece of mdf in an L shape the same size as the other piece.

3. Attach a bearing to the L with a 5/16 bolt.

4. Screw the L to the motor so that it can pivot on the short side of the L.

5. Attach a spring and screw so the tension on the filament can be adjusted.

Step 10: Wiring and Electronics

Extension wires need to be soldered from each motor to the ramps board. I chose to attach it to the side because it was one of the few places that I still had room.

1. Solder female header pins on to each wire. (I salvaged mine from and old ATX power supply that no longer worked.)

2. Then, attach all the components to the ramps board.

3. Another ATX power supply is then used to power the ramps board. Remember to bridge the green wire to ground or the power supply will not turn on.

Step 11: Final Thoughts

The printer is not currently functioning as the extruder motor is broken, but I hope to fix that soon.

Once I get it working, I plan to print some of the wood parts in plastic to strengthen the machine.

I have run through dry prints and have all the axes working and calibrated.

When I completed the instructable, it was reentered into the contest and I lost all of my votes so far. I would really appreciate it if you would consider voting for me in the contest.

Thank you for reading. If you have any questions feel free to ask in the comments below.

Remember that everything I did for this printer can be done in a different way. All you have to do is imagine and you can come up with a solution!



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    26 Discussions


    2 years ago

    I there.can you tell the printers where you got the nema 17 motors?

    1 reply

    Reply 2 years ago

    The best advice I can give you is that the older and heftier the printer is, the more likely you are to find good stepper motors.


    2 years ago

    Dear Rednax718,

    I am thinking of 3d printing all the wooden parts as it will be free from my school, can i ask what are the dimensions for all the parts?:)


    Sincerely Gabriel

    1 reply

    Reply 2 years ago

    Sorry, I can't give you specific dimensions as this post is more of an overview of all the parts. if you can print for free at your school, I would suggest that you use one of the RepRap designs on their website.


    3 years ago

    really it's a great work from a small clever engineer but i want to ask you if you could clarify the extruder L shape and spring part or give it a clear shot thanks in advance :)

    3 replies

    Reply 3 years ago

    The extruder is a variation of the bowden extruder, I just made it out if wood instead of 3d printing the oarts. To find more information about it Google "bowden extruder".


    Reply 3 years ago

    i know it's a variation of bowden extruder but i want to know or to see a closer view of it cuz i'm manging to do it from wood also just to minimize the cost :)
    Thanks in advance :)


    Reply 3 years ago

    Sorry, I have already disassembled this printer and used the electronics to make a new one. Good luck on your build.


    Reply 3 years ago

    The printer is currently not working so I wont be able to make a video yet. As soon as it is working I will film it.


    Reply 3 years ago

    Unfortunately I will not be able to make a video tutorial as the printer is already built but I am happy to clarify any questions you may have. My printer does not have a heated bed but one could easily be added. It can melt any plastic filament and even cheap nylon trimmer line.


    3 years ago

    thanks for your fast reply i'm from india i don't have access to any 3D printer so i want to make one u idea is great can u instruct me to make x &z axis from wood i cant get from here and did it need hotbed how to find filament or it can melt odinary plastic filament

    1 reply

    Reply 3 years ago

    As you can see from the pictures the x and z axis are just two pieces of wood glued perpendicular to each other, one piece has a nut in it and the other has holes to insert smooth rod.


    Reply 3 years ago

    the controler board is a Ramps 1.4 and arduino combo that I purchased from ebay. The motors were salvaged from old printers and scanners. The extension cords were just old usb cables but you could use any wire.

    I wanted to try something like this.

    I have taken apart seven regular printers and I got no stepper motors, and no bearings or bushing. Just seven 8 mm linear rods.

    Any idea where I can find the printers with stepper motors?