Materials are first. The tools you can improvise. You will need the following items to build the HMA (Hot Melt Adhesive) Extruder:
* 3/8" Plywood (~6.5" x 4.5")
* NEMA17 Stepper Motor (Unipolar - match up to your driver) with Gear (8mm - 16 teeth)
* Large (46mm - 100 teeth) Nylon (or some sort of plastic gear) with teeth that fit your Stepper Motor Gear (I got mine from a Lexmark Inject Printer)
* 4 Metal Bearings - mine are 15mm outside and 6 mm inside.
* 9 to 10 - #8 1.5" Bolts and/or #6 Bolts
* #8/#6 Washers (I used about 20 in this design)
* #8/#6 Lock Washers (I used 2)
* #8/#6 Nuts (8 to 10 used)
* #6 0.5" Screws (I used 4)
* Metal L Bracket 1.5" x 1.5" with 2 holes in each side
* Mini Hot Glue Gun - Low Temperature
(HiTemp is shown in picture - Do Not Get This) from Walmart ($2.97)
* Mini Hot Glue Sticks - Low Temperature
- Bag of 30 from Walmart (~$3.00 or so) *** You can get colored ones and different kinds from Craft Stores such as Micheal's or Benjamin Franklin's (on the East Coast). Walmart just has 1 kind. Be careful ... some are .27" in diameter... some are .28" in diameter. You will want to just get 1 diameter and stick with it otherwise you will have to adjust your bearings again.
* Popsicle Stick
* Slotted Metal Bracket ~2" Long (slot needs to be able to fit #6 or #8 screws)
* Big straw or tube of some sort ~4" long and ~3/8" inside diameter... make sure a glue stick will slide freely using gravity.
* Wire - around 4 feet long with enough conductors to wire your stepper motor to your stepper driver. My wire had 6 conductors and was 28 gauge (an ex PS2 keyboard cable I think).
* Small Zip Ties
* Piece of Glass (I got mine from scanner) to print on
* Isoproply Alcohol for cleaning the print surface (glass)
* Computer to talk to your printer's electronics.
* Software (I use Pronterface => https://github.com/kliment/Printrun
If you do not have the 3D printer electronics already like I did not then you will need those too. I am using an Arduino Uno with Teacup firmware. I have built a custom stepper motor driver for my Extruder. I use a 3 axis stepper motor driver from HobbyCNC.com (http://www.hobbycnc.com/
). It is a really nice kit and works great. Instead of using the parallel port from the computer the Teacup firmware and Arduino control the HobbyCNC stepper driver through a shield I made that basically wires some pins to a 25 pin DSub to pretend it is a printer port. The custom stepper driver I made I basically designed on my own using 2 ULN2803A chips stacked on top of eachother to give 1 amp per coil. I regulate the current with an automotive lightbulb (not sure how many watts). I then modified the Teacup firmware to control the 4th stepper motor for the extruder directly instead of using a driver with step and direction control.
and finally you will need some sort of computer controlled XYZ platform such as a CNC router or RepRap. I made my router from parts from Lowes and plans from Solsylva.com -> http://solsylva.com/cnc/13x13x5.shtml
. It is their 13x13 machine and it cost roughly $100 in parts to build (without the motors and electronics). You will need the Stepper Motors and Electronics too. This is probably where most of the other money lies in a 3d printer besides the extruder cost. There are some really great Instructables that feature how to build low cost CNC machines that will work great. One of the least expensive and most popular would be the McWire CNC Mill -> http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/
* Hot Glue Gun - Hi Temp for gluing stuff to wood.
* Screwdrivers (Flat Head and Phillips Head)
* Drill (Hand drill is fine)
* Step Drill Bit (http://www.harborfreight.com/3-piece-titanium-nitride-coated-high-speed-steel-step-drills-91616.html
* 1/8", 9/64", and 1/4" Drill Bit and a few others ... just a set from Lowes - I have a set by Dewalt which are nice.
* Dremel Tool with Router Attachment and 1/4" router Bit
* Dremel Tool with some sort of wood eating bit
* Wood Chisel
*** This is used to recess the hot glue "Hot End" into the wood so the glue stick is even with the gear and bearings (which are right above the surface of the wood).
* Needle Nosed pliers for adjusting nuts and stuff.
* Exacto Knife
* Side Cutters
* Soldering Iron and Solder
* Electrical Tape and/or Shrink Tube