Robin2:
And how many of those 3D printers are using L298 drivers for their stepper motors?Think about it ... those guys will wish to save every penny in materials cost but they don't use L298 drivers. That must tell you something.
...R
yup you have a point there, if you look at those l298n modules on sale in ebay
you can see the rather large heat sink and discrete diodes (they are no included on chip)
that module alone easily cost more than those a4988 and drv8825 modules
on the other hand given the heat sink it would be more likely the l298n can take a full 2 amps driving a moderately high current stepper, that would obviously make a difference in terms of speed
actually i've not actually worked with a4988 and drv8825 but i think they are fine motor drivers, just that i've actually meddled with some smaller mosfets transistors, i noted that small mosfets do not necessarily offer low resistance and large mosfets are expensive. a smaller mosfet with higher resistance would likely need no less cooling that that l298n with a decently sized heat sink and my guess is h bridges with good mosfets are expensive naturally. even if i choose to do the same - separate the driving h-bridge from its control mcu, the good mosfet h-bridge may well be a pretty costly affair in that design.
a4988 and drv8825 (which i think is better) are pretty nice drivers
but as it goes, i'm happy to play with the l298n and even the l293d for my own experiments with microstepping which means doing current sensing