RepRep – Stepper Drivers and a Power Source
The main board with the Step Stick drivers added.
In the last update, it was mentioned that there were a few components left to make the control board complete. It can be said that the board is two steps (ignore the pun) closer to being complete. Four step stick stepper motor controllers have been purchased from china and have arrived in good condition (although to the wrong address!) and assembled and installed to the Sanguinololu.
The next task was find / adapting a 12v power source to the system. This implementation accepts a standard PC atx 2.1 power supply and requires only the 12v auxiliary power connector for the CPU. As it does not look tidy and can be difficult to manage, the extra unneeded cables and connectors have been de-soldered from the PSU PCB. It is a very bad idea to simply cut of cables from the PSU as you may end up shorting the system out somewhere down the line.
Thats alot of de-soldering going on there.
The other set of wires left connected are a single ground connection (black) and a power on (green). This is so the PSU can actually be turned on using a toggle switch of some description.
The modified power supply
Again at the end of this update the only thing left to do is find two suitable MOSFET’s for the heat bed and hot-end and some cable crimps (The headers and sockets have already been purchased).
RepRap – The Story begins
Just needs two MOSFETs and the stepper motor drivers
For those of you who are not familiar with the Reprap project, it is an open source idea to create machines that can reproduce them self. In non technical language, 3D printers. A 3D printer just like a normal printer receives commands from a data source (PC, SD card, Compact flash, camera etc etc…) however instead of using ink, it uses plastic.
This means that we can print 3D objects designed using a CAD package . So here I begin with my RepRap Journey. I’ve already gone through a lot of the process, getting parts for both the structure and electronics.
Most of the electronics that have been designed to control the Repraps’ various parts are based on the Arduino open source hardware project, and mine is no different. Based on the Sanguino Arduino, the Sanguinolou is a single board solution with all stepper motor end stop and heating element drivers present.
Being the graduate that I am, finances are tight and as such everything that has been done has been done as cost effectively as possible (That means best value, not cheapest, I’ve made that mistake before). I started this by getting a free prototype PCB from spirit circuits, who will mkae a one of PCB for free. However it doesn’t come with soldermask or silkscreen, and will be in a much larger panel with their advertising. I think that is more than fair since it is free and thus I have my PCB. By scavaging around for parts, left over from other projects and asking the right people, the only electronics I’ve bought have been the Atmel 644p Microcontroller, the FTDI USB chip and the 12v ATX power connector.
Notice the bad cuts?
That’s all for the electronics so far, the mechanical side I have based the design on an over-sides huxley (There are a few versions of the Reprap design, check RepRap.org for all the current ones). I am using M8 sized threaded rod for the structure and M8 silver steel bards for the rails.
So far I’ve produced the main electronics board, burned the bootloader for the Ardunio software and uploaded the latest sprinter firmware. I’m waitnig for some stepper motor drivers to arrive from China and for Robotics Common to have their RepRap mendal arrive so the plastic connections can be made.