1) Extruder board - controls the flow of plastic. It feeds signal to a motor that gradually feeds plastic into a heated build head (not shown). This shows the original board that drove a DC geared motor and controlled temperature of the extruder directly. As a result, this board would usually get hot. Due to this, later upgrades would only require low power signals from the board to drive heater element relays and a separate extruder driver board. At a later time, two types of extruder driver boards were tried and were mounted on top of this board (not shown).2) Motherboard. Programs can either be fed to this board via a USB cord from a PC or programs can be loaded using an SD card (SD card slot is a rectangular metal thing located on the lower right of the board)
3) Stepper motor drivers (3 of them). These will accept digital signals from the motherboard via ribbon cable. The pulses to the stepper motor driver are amplified so they achieve precise movement of the X & Y build platform. A third board controls a stepper that controls raising & lowering for the Z dimension. In addition to getting signals from the motherboard ribbon cables, they also get signals from end-stops.
4) Relay Kit mounting location. On the top stepper board is a mounting needed for a "relay kit". This accessory allows the extruder board to remain cool since it only needs to signal a relay board rather than drive the heating elements directly. One relay controls current for heating the extruder while the other controls current for heating the build platform.When assembling, the electronic boards seemed easier to mount if I could get to both sides at once. So, I mounted the board on a vice and attached the electronic boards as seen in the photo.
On each piece, I sanded the tabs down AHEAD of time so the project could be put together more easily. It worked. By only screwing and not gluing, future repairs will be easier to perform. There are LOTS of screws to this kit. The task of tightening them took quite a while!
