One RepRap Motherboard, Multiple RepRaps?

Maybe this has been asked, a quick search didn't provide much, but being new to the RepRap process, I was thinking. How many I/Os and pins are being used? And would it be possible to theoretically control more than one RepRap Cartesian bot with one RepRap motherboard? Or is that level of multitasking too complicated for the ATMega644? I would also assume they would have to be as close to identical as possible. I could see them printing the same part, but ideally I would like them printing separate pieces, (but maybe to the same device).

Also, has anyone looked into the Illuminator X Machina as a potential controller for the RepRap?

The idea being, say you can't fork over enough time/money/blah for more than one controller, but you can manage to build a couple Cartesians? You could then make/sell/give away more parts at twice the speed to help fund additional projects.

But again, I'm still rather new to the RepRap movement, (and microcontroller programming in general). I understand that a potential stepper controller might be an issue, and so forth.

Anyway, that's just my idea for now.

EDIT: I also posted this in another forum to elicit more replies if its against proper forum etiquette I apologize.

EDIT 2: A possible drawback was mentioned on IRC by Vik, that it could possibly generate too much interference/noise. I wouldn't know unless I tested it, but just something else to think about.

... it's questionable, if the cost for one or more additive 'small' controllers, compared to the costs of the multiple stepper-drivers and wiring, is it worth.

I bought an Arduino Mega with more than 50 I/Os for 50 Euros here in Germany and the 'small' Arduinos are around 20 ...

I don't think that trying to share major components (except maybe the power supply) between two RepRaps is practical.

On a single RepRap Motherboard there are only enough stepper drivers to run one Bot. Using the non-motherboard electronics (separate driver boards for each stepper) you could use a larger Arduino and add enough stepper drivers, etc, to drive a second Bot but you would need a major re-write of the control software.

Ah, thank you both, thats basically what I wanted to know. All this was assuming I would design/build/print my own Sanguino based PCB with the appropriate number of stepper motor driver connections. I'm not necissarily concerned about the software re-write, more on just the possibility of such. IE, can the ATMEGA644P actually support the load?

... when you've separated the motor-current with discrete drivers, it's only some Milliamperes at 5 Volts what's needed for activating the stepper-driver input pins ...

Viktor

While the motor movements could be consider digital where they could run in lock step the extruder control of the heaters would have to be cordinated.

You then get into the purely mechanical issues of tolerances between the machines and potential Z-axis calibration. Though I image one you delt with that it would make repative parts runs more reasonable.

Then what happens when one machine has a fault?

@freds, depends on the fault I suppose. If the extruder blows, or one of the stepper drivers burns up. It should still leave one completely functional machine and all that would be required potentially is to reprogram or alter a few commands.

In this scenario I would not have EVERYTHING on one motherboard. The Stepper/Extruder Controllers would still be controlling their each respective parts. Only a modified Motherboard to sync it all together.

Although, I would still prefer to have each RepRap produce different parts simultaneously from one motherboard, but the more I think about it. It seems like it would be far too taxing for one ATMEGA644p. I'm just now starting to delve into the guts.

Also, had an idea using accelerometers...which I'll make another topic for.