Motor Controller ( muliple L293 ) per axis?

Would it work to attach muliple L293, or muliple L298's to increase the amprage per line? For example I would tie the input's for input A of both of them to the same io pin, as well as tie the output's, this should theoreticly turn both output's on at the same time which would give me 1.2 A instead of the .6 ( or even triple them or more )

Just an idea, and I am more wondering if I am missing something, ( I will probably try it eather way, but I figured I would get some input first )

While the L293/L298 combo doesn't do microstepping, running multiple drivers in parallel is perfectly fine. I think the L293 can even be stacked on top of each other, so you can, let's say, put 4 of them onto one socket.

A small caveat is, chips aren't always as identical as one would wish, so stacking two 0.5 A drivers on top of each other doesn't give 1.0 A, but more like 0.8 A, because the driver with the lower resistance will take more than 50% of the required current.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

... to 'average' inhomogenities in parallelized current-drivers output I'm adding them through 0.2 Ohm resistors ... for higher currents than 1 Amp this resistors should be smaller, e.g. 0.1 Ohms for currents around 3 Amps ...

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Viktor
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Thanks, I know both of them do not allow micro-stepping, but for what I am experimenting with I will not need it, I am attempting to replace steppers with optical encoder's and dc motors, ( I know that it is not going to be an easy switch, but The worst thing that can happen is I fail and switch to steppers )

Uhm, for running a DC motor, a PWM-able DC switch is a much simpler choice? They can do 10 amps easily. Also, RepRap has a DC motor driver already:

[reprap.org]
[reprap.org]

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Are there any firmware's that work with dc motors? My current plan is basicly to use the dc motor driver 1.1 ( a slightly different thing, but based on the L293 ) But using an optical encoder to know exactly how far it has gone and speed ext...

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Are there any firmware's that work with dc motors?

Not aware of one. Gen3 electronics and before used to use DC extruders, but that was just on/off, without positional or speed feedback.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Gen3 used Extruder Controller board 2.2, which communicated over rs485, so one could easily have multiples. It needed its own microcontroller to have IRQs free of any other tasks to be able to react fast. It didnt had position sensor onboard, but had a quadrature connector which connects to Magnetic Rotary Encoder board (link in header of same page), and this other board can provide positional closed loop function, thus turning the dc motor into a servo drive. I think its possible to use these electronics to make servos instead of steppers, but you would have tweak them a little and also to re-write firmwares. If you actually want to make them hardware wise, there are some toner transfer ready images on this page, but beware, that is very old, back from the day when gen3 was fresh and those were *the* electronics. Really not advisable for new designs.

Not sure if this was mentioned, looks like it could work.

[reprap.org]

Not sure of the status but a good start anyway.

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Kalle
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Lahti, Finland
The only stable form of government is Open Source Government. - Kalle Pihlajasaari 2013