Pololu Electronics
Release status: Experimental
| Description | Alternative Mendel electronics based on the Arduino Mega and the Pololu A4983
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| License | GPL v2
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| Author | |
| Contributors | |
| Based-on | [[]]
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| Categories | Electronics
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| CAD Models | Eagle
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| External Link |
Introduction
Note: this design has been tested on the bench, but not yet in an actual RepRap Mendel.
This is an alternative set of electronics for Mendel that is being designed to be as likely as possible for Mendel itself to be able to print.
It is based on the |Arduino Mega and the Pololu A4983 stepper driver.
As Nophead has pointed out, that Pololu driver is a nice design, but with one big shortcoming: it will run hot, and is difficult to cool because it's so small. So what I've done is to design the electronics in such a way that they both perform their function and act as a physical duct for the flow from a fan to direct their own cooling. A happy side-effect of this is that the resulting PCBs are very simple, and can be made single-sided without any thin tracks. That is to say, when we get RepRap making electronics, they will not represent too high a first hurdle.
Indeed, so simple is the design that it is quite straightforward to make it on a couple of pieces of stripboard. That is how I prototyped it.
All the Eagle design files for this are |in the repository here.
Schematic
Here is the schematic. The Pololu boards have 16 connections that come out of the edges on a 2.54mm pitch. Those are the twin columns of 8-way connectors shown on the schematic. I deliberately did not design a single device for the Pololu boards, as half their connections go to one PCB, and the other half to the other. The whole thing makes a box structure that both simplifies connections and also ducts the cooling air, as mentioned above.
