That’s the usual outcome, but if one half-winding is reversed it will behave poorly. Given that you observed “motor stalls/ squeals”, it’s worthwhile to verify the absolute basics.
It works the other way: a smaller step size (more steps/rev) requires less torque to move the platform during each step. Think of it as pulling a car up a hill with a comealong: it’s easier to move it one inch per click than one foot per click.
No. Set it to 10 k, because that’s what the good folks at OMTech seem to think is appropriate. Which is why I recommended it.
The step length is not a free variable. It is exactly determined by the leadscrew pitch and the pulley tooth ratios.
Measure the distance between threads on the leadscrew. Mine has a single-start thread with 10 threads in 40 mm, so the thread pitch is 4 mm.
Count the number of teeth around the motor drive pulley and a leadscrew pulley. Both have 15 teeth in my OMtech.
Then calculate:
mm/step = (pitch / step/rev) × (motor teeth / leadscrew teeth)
400 µm/step = (4 mm / 10 k) × (15 / 15)
Which, now that I work it out, does not agree with the 0.399 µm/step shown on the LightBurn Vendor Settings screen. It’s off by a tidy factor of 1000, which shows my KT332N controller uses millimeters, not the microns used in other Ruida controllers:
400 µm = 0.400 mm
Verily, a foolish consistency is the hobgoblin of small minds.
Bonus: trust, but verify.
So calculate the mm/step for your hardware and enter it in the Vendor Settings for the Z (or U, depending on the controller) axis, with attention to the units. The 6445 doc says it uses microns, so you’d use 400, rather than my 0.400.
Then set all the speeds to 4 mm/s and all the accelerations to 50 mm/s².
The KT332N requires a reset / power cycle to put some of those values into effect. I have not been able to get consistent results without a reset, so I think the firmware recomputes some internal values, but not all of them.
With all that lined up, see what happens …