I did my homework and figured out what else I would need.  I placed orders and figured what would be the (almost) final DIY 3D printer cost.

Gathering All the Pieces

I made purchases from Fastenal, Menard’s (local home improvement store), and some online places (mostly ebay).  Here’s my list:

diy 3D printer cost for nuts, bolts, and bearingsFrom Fastenal:

  • 2 – 626 ZZ bearings – These will hold the threaded rods that will provide Z-axis (vertical) motion.
  • 44 – 623 ZZ bearings – These are used all over to make sure the printhead moves smoothly on each of the 3 axes
  • 55 – M3 20mm cap screws – M3 is the 3mm metric size.  20mm is the length.
  • 20 – M3 30mm cap screw
  • 100 – M3 washers
  • 20 – M3 fender washers – Fender washers are larger than regular washers.  I used them when I wanted a little more surface area touching the plastic.
  • 20 – M3 hex nuts
  • 50 – M3 nylock nuts – Nylock nuts have a little nylon ring built into the nut which keeps the nut from loosening.
  • 3 – M6 threaded rods
  • 3 – M6 drill rods – These are smooth steel rods that guide movement along each axis.

From Menards:

  • 1 – 3mm plywood (about 12″x12″).  This is more of a craft plywood. It is made of more layers than regular construction plywood and should be stronger for its thickness.
  • 8 – washers 1/8″ inside diameter, 3/4″ outside diameter – These are used as belt guides wherever there is a pulley bearing.  The 1/8″ inside diameter is about the same as 3mm, so it fits over the screws, but the larger outside diameter is enough to stick out past the bearing and keep the belt in place.

Motors, Electronics, and ExtruderOnline/Ebay:

  • 4 – NEMA 14 stepper motors (NEMA 14 indicates that the mounting holes are 1.4″ apart). There are plenty of warnings about making sure the motors are strong enough.  Normally RepRap printers use a slightly larger NEMA 17 motor, so I made sure the motors I bought had plenty of torque.  I probably could have used cheaper, slightly less powerful motors, but I figure it was safer to make sure the motors would work.
  • 1 – Electronics. I am using an Arduino Mega 2560 with a RAMPS board.  This is probably the least expensive option.  You miss some of the features that other boards have, but this one works and has plenty of documentation.  You can read about it at:http://www.reprap.org/wiki/RAMPS_1.4
  • 1 – Heatbed – the place where plastic is printed. You connect it to the electronics and it is turned on and off automatically to keep the correct temperature. Read more at:http://reprap.org/wiki/PCB_Heatbed
  • 1 – Extruder hot end – made up of a nozzle, heater, thermistor and more.  This is the part that melts the plastic and places it just where it needs to go.  The thermistor sends the temperature back to the electronics so that the nozzle can be kept at the right temperature.
  • 3 – End switches – little electronic devices used to tell the electronics when the printhead has reached the start position along each axis.

My DIY 3D Printer Cost

That is all of the major purchases.  Certainly, there were other things to buy – little things like more screws, nuts, and washers.  I stopped keeping track after a while, but I estimate that the total DIY 3d printer cost was about $500.  That doesn’t include the parts I already had – the PC power supply is the big one, but also things like wire, solder, and connectors.