Hi JJB,
This driver is in the "Pololu" family, and have the same feature of configuration (as we name it) as the one used in Ultimakers late family 3D printers (as far as I'll know). Actually your "hack" is just the same thing as I did with my printer, that is using "PoLolu A4988".
You said it improved your print about 80%, yes that was missing step, -but then there is some sign of it still, right. When things improve like this, we might wonder; is there still some missing steps? No there is not! So what could it be then, the answer is "production tolerances". It is maybe a cheap (Chinese?) stepper motor.
The truth is; those steppers might not stop at the "exact" same position when the current is reduced. This is actually true for every stepper motor, if we go "deep" enough into it...
This is why we still may have sign of those stripes, if we look close enough into it.
You can have a better stepper motor, or you can gear down the speed by 2 (sure using belt for this), in order to improve the print further.
All this said, however, most of the steppers today is made in China.
So, if you like to have “real good” quality, the stepper motors used here for X/Y play an important role.
Thanks.
Torgeir.
By "hack" I mean this:
I dont use chinese drivers. Everything is original.
I did the "hack" and the zebra stripes are almost gone.
Changing from drv8825 to a4988 (originals) also "solved" the problem.
Changing from drv8825 to a4988 (chinese) made it worse.