easy drivers vs pololu carriers A4988's vs DRV8825's

So basically by question is, witch one of these would be the best bang for my buck?
I planning on using them for my 3d printer build.

I'm using a arduino uno, and 'TeapCup' firmware.
Still undecided on the motors.

is there really that much of an advantage to the DRV's vs the A4's other then the the DRV's having 1/32 stepping

I know this isn't a 3d printing forum, but does anybody know if I really need 1/32 stepping or even 1/16 stepping?
Would 1/8 stepping be fine if i just went with the Easy Drivers?

i found some easy drivers on ebay for $2.33 is this to good to be true? the seller has over 90% customer satisfaction.

anyways thanks for you help in advance guys.

First thing you MUST figure out is how much current your stepper motors need.

The Easydriver can only provide a max of 750mA I think - so probably 500mA would be more sensible.

The BIgEasydriver and the Pololu A4988 both use the same chip which can supply 1 amp - perhaps a bit more but hen you will need to add heatsinks and maybe cooling fans. The stated 2 amps is very optimistic.

The DRV8825 can supply a bit more current than the A4988.

If your motors need more current (which would not be unusual) you will need a more commercial driver at a higher price. The principal of operation will be similar.

As far as I know the BigEasydriver defaults to microstepping whereas the Pololu A4988 defaults to single stepping. Neither is better - but being aware will avoid unexpected behaviour.

...R

IMO microstepping is better, but x8 or x16 is enough - it reduces resonance,
resonance is the commonest cause of mis-stepping. Resonance is less of a problem
in belt drives compared to leadscrew drives though, since the belt acts as mechanical
damping.

thanks guys

ill get to work on finding motors then.\

let me ask this, putting current limits of these chips aside, witch is more reliable, is there any known problems or major drawbacks to either of the chips?
should i worry about buying chips for so cheap on ebay?

I don't think there is any difference between the chips that is not shown on their datasheets.

I get the impression from comments here that some of the driver board clones on Ebay may not be as consistently made as the official Pololu or Sparkfun products. I have no experience of them myself. I bought Pololu A4988s.

My suggestion would be to get at least one "genuine" product so you aren't scratching your head for hours wondering if the problem is with you or the driver board.

The Pololu A4988 webpage has very good information about using the product and it is probably a good guide no matter what board you get.

...R