6800 steps per mm seems very high. At 5mm/sec = 34,000 steps per second which would push the limits of the mega chip.
A 5mm rod with .8 mm /rev = 1/.8 * 200 * 16 steps = only 4000 steps per mm
I would have to guess you have a drv8825 driver set at 1/32 steps to get this high a value.
Try setting the driver at 16 steps. At 4000 steps your resolution is .00025 mm
A 5mm rod with .8 mm /rev = 1/.8 * 200 * 16 steps = only 4000 steps per mm
I would have to guess you have a drv8825 driver set at 1/32 steps to get this high a value.
Try setting the driver at 16 steps. At 4000 steps your resolution is .00025 mm