In order to stick to my design goal of an AUD$1000 budget I decided to start a bill of materials spreadsheet. This would be a handy tool to keep track of budget and also allow me to show people if they wanted to try making something similar. Below is a list of the major components in the initial round of purchasing. Note that all prices are in Australian Dollars (AUD) and approximate at time of purchasing (Q1 2014). Also note that some of the eBay stores don’t stock these items anymore.

• RAMPS 1.4 Starter Pro Kit (eBay - LearCNC - $308)
  • Complete electronics kit including RAMPS 1.4, LCD, Nema 17 motors, heated bed, GT2 belts with 20 tooth pulleys, thermistors and plenty of wires. I liked that this kit was complete and I didn’t have to source everything separately.
• 6 x SF12-700mm 12mm Hardened Round Shaft (eBay - silvers-123 - $106)
  • I wanted a decent size build volume. Having 700mm shafts would give a maximum build height of around 350mm which I thought was plenty. Any longer would also make the printer more difficult to move around.
• 10 x 12mm LM12UU Linear Ball Bear Bearing (eBay - beautyzz2009 - $15)
  • These were what most people were using on their linear shafts.
• 12 x 12mm SHF12 Linear Rail Shaft Support (eBay - may139188 - $30)
  • To ensure the shaft is mounted strongly to the frame. I did think of just having a perfectly sized hole in the top and bottom plates (for the shaft to sit in) but that would be a pain to dismantle/maintain.
• 10 x Flanged Ball Bearing F685ZZ 5*11*5mm (eBay - angelinvestment2010 - $10)
  • Placing two flanged bearings together (facing each) other is a very cheap and easy way to create a pulley. I chose the 11mm diameter because it almost matches the diameter of the 20 tooth GT2 pulley teeth. This meant that the belts would remain parallel and aligned through the whole range of movement.
• J-Head Hot End for 3mm Filament (eBay - geeetech-official - $33)
  • This style of hot end seemed to have decent reviews for the price.
• Greg’s Hinged Extruder Kit (eBay - vpeters1984 - $30)
  • This was to be the only 3D printed part that I needed to buy. This was the most widely praised reliable extruder out there. This guy was selling complete kits which meant that I didn’t have source any of the nuts and bolts separately.
• 4m GT2 Timing Belt and extra GT2-20T pulley (eBay - LearCNC - $20)
  • I needed some extra length as the three axis are much longer than regular cartesian printer’s axis.
• Pack of 12 Traxxas Rod Ends Large with Hollow Balls (eBay - rchobbies4life - $14)
  • These were popular cheap and reliable ball joints for delta printers.
• 4mm x 750mm Hollow Carbon Fiber Tube (Hobbyking - $9)
  • I chose this diameter because it fit snugly inside the rod ends (once they were drilled out to 4mm).
• Cork Pot Placemat and Chopping Board (Local discount shop - $9)
  • The placemat was for insulating the heated bed. The intention of the chopping board, made from some kind of nylon, was for manufacturing small brackets and mounting blocks.
• 200mm x 214mm Borosilicate Glass Bed Plate (eBay - LearCNC - $26)
  • I really liked the idea of printing on glass rather than on the PCB heated bed. Having a perfectly flat glass plate would make calibration and first layer adhesion easier (this proved true).
• 1m PTFE Tube for 3mm Filament (eBay - LearCNC - $13)
  • To achieve fast print speed and acceleration, I decided to use a bowden tube system for getting the plastic to the hot end. This meant that the print head would be nice and lightweight.
• Aluminium 40mm x 40mm x 1m L section (Bunnings Warehouse - $11)
  • For manufacturing motor brackets.
• Push Fittings for bowden Tube (eBay - sellerbible - $8)
  • For spares.
• Spiral Cable Wrap and Self-Adhesive Ducting (Bunnings - $30)
  • I wanted the printer wiring to be very neat and tidy. I’d seen many scratch-built printers with wiring all over the place and not much thought given to smart cable management. The cable wrap would neatly bind the hot end wiring to the bowden tube. The ducting would be used for the wire bundle going from the base of the printer to the top.
• 12V 20A Switching Power Supply (eBay - zhengzheng2011 - $20)
  • Just a generic cheap power supply. Sufficient for my purpose.
• IEC13 Socket with Integrated Fuse (Jaycar - $8)
  • The intention here was to make a cover to go over the end of the power supply that safely contained all mains wiring. I found this neat little socket with fuse and figured it would be a nice neat solution. Also, by not hard wiring the mains lead, I would not have a cable dragging everywhere and getting caught while working on or moving it.
• Assorted metric nuts, bolts, washers etc. (Hobbyking)
  • I tried really hard to ensure that most fixings on the printer would have M3 thread, except the shaft mounting bracket bolts.

These items would be enough to get me started. It ended up taking around two months to receive all of the above products from mostly China-based sellers. I was able to design other parts of the printer while waiting.