Here’s a new synthesis post on the RepRap 3D printer. The official wiki is very comprehensive, but it is definitely not an easy to sort through this mass of information. So here’s my view after some research on the different electronic control systems available.
This is the “official” electronic of Mendel. The specificity of this controller is its modularity. Separate function are distributed on several cards: The motherboard is connected to the computer and individual cards supply power to each motors. The wiring is quite complicated, but when something goes wrong, it’s probably easier to debug. Another advantage is that if something fail, you only need to replaces a module and not the whole system. You can notice the presence of an ATX type connector which gives the to possibility to directly plug a PC power supply !
From right to left: the stepper controller, the extruder controller, the motherboard and the optical limit sensors.
The brain of the motherboard is a Sanguino . The Sanguino is an Arduino clone, built around a more powerful microcontroller, an ATMEGA644P. It is fully backward compatible with the arduino environment.
The stepper driver is an Allegro A3982 . This new generation of controller that supersedes the traditional L297/L298. One big advantage of this circuit is that it generates less heat and requires no heatsink. For cons, the chip is only available in SMD package, which complicates realization of DIY PCB.
Today, these board seems difficult to find for sale.
This is a “all in one” board, designed by Camiel from Mendel Parts. The 4-layer PCB, can only be produced by industrial tools. This system is relatively expensive, it costs ~ 150 € from Mendel-parts.
The name of this card is an acronym for “RepRap Arduino Polulu Mega Shield.”
The power driver of stepper motors is still an allegro chip, but it is pre-assembled on a small interface board: the famous polulu driver. This greatly simplifies the installation on a DIY PCB.
The release 1.2 is a design that can easily be soldered at home. In version 1.3, the double sided board and SMD components introduced make it difficult to realize. You can read HERE an article about soldering this board.
Between the cost of the Arduino Mega and the arduino shield this solution a bit pricy …
The generation 7 electronics is another single board driver system. The philosophy is however very different since there, everything is done with DIY build in mind. The ultimate goal would be to mill the PCB on a RepRap equipped with a drill, a manner to go a little further into self-replication. The circuit is single-sided and uses only through hole components. In the latest version, unnecessary exotic connectors have disappeared, which make it even more easier to build. We find an ATX connector here too.
The Gen7 system is still experimental and has not been widely disseminated, but I find this is a very interesting project for those used to engrave their PCB at home.
Here we find both an integrated Sanguino, and the polulu drivers. The performances of this board should be somehow equivalent to the Gen 7. The circuit is not very complex, but it is a double-sided PCB. Considering the cost of the kit (~ € 40), I think it’s not worth trying to engrave it…