3 Axis Control via one stepper driver

Heres an interesting idea I've been playing around with in my head. How about using one stepper driver board to control 3 axis. The idea is that each of the four stepper motor wires (insert technical verbage here) would be split into three+ channels, each one controlled by a transistor.

This should free up 3-4 slots on the arduino as well.

It would also require about 12-16 transistors, but setting it all up should be pretty easy.

Since the instructions from the controller are sequential, theoretically we should be able to get buy using just one stepper board. What do you all think?

... for what

More problems and misbehaviour than cost saving ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Obviously there would be some problems to its implementation but there are some strong benefits.

First, it simplifies the reprap, less electronics. With one stepper driver and an array of transistors, all axises and multiple extruders could be controlled with no additional electronics needed.

As you mentioned, there would be a cost savings. One stepper driver board + transistor array would cost around $50... this would have a big impact on the overall price to build a mendell. With a cheaper price tag, more fabbers might join the cause.

Another benefit would be the number of pins required to control the motors/extruders. The stepper board would require two pins, and each axis just one additional pin. That means our little arduino could control more elaborate machines.

Lastly, going with the whole reprap spirit of a self replicating machine, a reprap could possibly build its own transistors (at least in the near future). Basically there would be one less reprap component that the machine couldn't make for itself.

... i don't see any real benefit either

You can get complete single motor-drivers below $20 (i remember seing some singlechip-drivers even below &10) which need two pins per motor (DIR, CLOCK) and you can drive two or more motors synchronous so your mechanic is much faster/accurater than with only a single axis moving per timeframe ...

The advantage of a discrete transisitor-array over a singlechip-solution is mainly the availability of the parts ... maybe this will change if we can fab usable basic electronic componentes, but this is a long term idea ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]