X Axis travel issues, and a micro-stepping q

Hi there, I was having issues with x axis positioning problems which I think I have pinned down to both too tight v wheels eccentric nuts, accompanied by a too tight belt (I was cutting a bunch of 5mm notches across a board, some were spot on, some were as thin as 3.5mm). But in my fiddling to try to figure out what was happening I thought I’d bump the stepper micro-stepping up to max, which had the effect of some extremely violent movement… it seemed to be going 4 or 5 times the distance it should have, but in the same amount of time. Is this the expected behavior of the micro-stepping feature?

So I fixed the tension on the X belt, and adjusted the wheels on the carriage… better but still not great. The square in the attached image is perfect on the y, but about 3mm short on the x. the circle has issues, and the triangle is the same 3mm short on the x, and a ‘bubble’ on the top point which was the end position. Any ideas? The top row is with fixed belt and wheels, the bottom row was way to tight.

Here is the file, using Easel. Spindle is a 611 at speed at about 3.5
X axis voltage is 1.366v measured not moving which is apparently about 2.9A (is this the way to do it?)

Test 50mm.nc (78.6 KB)

Settings:

Grbl 1.0c [’$’ for help]

$$
$0=10 (step pulse, usec)
$1=255 (step idle delay, msec)
$2=0 (step port invert mask:00000000)
$3=3 (dir port invert mask:00000011)
$4=0 (step enable invert, bool)
$5=0 (limit pins invert, bool)
$6=0 (probe pin invert, bool)
$10=115 (status report mask:01110011)
$11=0.020 (junction deviation, mm)
$12=0.002 (arc tolerance, mm)
$13=0 (report inches, bool)
$20=0 (soft limits, bool)
$21=0 (hard limits, bool)
$22=0 (homing cycle, bool)
$23=3 (homing dir invert mask:00000011)
$24=25.000 (homing feed, mm/min)
$25=750.000 (homing seek, mm/min)
$26=250 (homing debounce, msec)
$27=1.000 (homing pull-off, mm)
$30=1. (rpm max)
$31=0. (rpm min)
$100=40.000 (x, step/mm)
$101=40.000 (y, step/mm)
$102=188.976 (z, step/mm)
$110=8000.000 (x max rate, mm/min)
$111=8000.000 (y max rate, mm/min)
$112=500.000 (z max rate, mm/min)
$120=500.000 (x accel, mm/sec^2)
$121=500.000 (y accel, mm/sec^2)
$122=50.000 (z accel, mm/sec^2)
$130=790.000 (x max travel, mm)
$131=790.000 (y max travel, mm)
$132=100.000 (z max travel, mm)
ok

ok so I had a look at the x axis motor and thought, is there a grub screw in that? I pulled the z motor off to get at the cog, dropped a screw in the rail, had to pull the x motor off and remove the belt to get the screw out, put it all back together, and the x axis is now fine… So not sure what the issue was. Now on to the y axis stutter issue, and test the Z axis!

PS. There was a grub screw in it btw.

It looks a bit out there, but I think that’s photo perspective… looks pretty close live.

Sorry for talking to myself lol

Do a search for “calibrate”.