Z axis off, Layers to tall.....

droftarts

@dingo007 said in Z axis off, Layers to tall.....:

@droftarts in Marlin it was set as below. The machine is home built, not commercial branded, the Z motors are 1.8 the Z screw looks like a normal z screw, nothing odd.

/**
Default Axis Steps Per Unit (steps/mm)
Override with M92
X, Y, Z, E0 [, E1[, E2...]]
**/
#define DEFAULT_AXIS_STEPS_PER_UNIT { 160, 160, 1600, 185 }

What was the microstepping in Marlin? You halved the X and Y steps per mm. The pitch of the thread on the Z screw is the important thing, saying "the Z screw looks like a normal z screw, nothing odd" doesn't help define what it is at all; there's a huge range. If you don't know, post a picture.

Ian

dingo007

@droftarts sorry i dont see any microsteppings in marlin config.... ! ive uploaded a photo, also i note, i measured the with of the circle printed it was 4.5, the length top/bottom of the elonagted side was 9, so im just guessing here that i need to cut my step in half somehow, now trying to narrow down the screw i have looking at RR config the only one that makes sense with new steps of 800 is trapezoid image url)

DIY-O-Sphere

@dingo007 said in Z axis off, Layers to tall.....:

4.5, the length top/bottom of the elonagted side was 9

Strange.. I was thinking about some tenth....

dingo007

@DIY-O-Sphere nope, i can assure you its way out.... X and Y seem fine.... but Z is definitly off

dingo007

So I think Ive nailed it, taking a guess at editing the Z steps... measuring the width says 4.5mm however circle height was 9... by my calculation that says i am 100% over stepping, playing with the variables in RR config and not knowing the screw pitch, i can determine that Trapezoid TR4 gives my the exact 800 number which is 50% of the 1600 it was originally set at. So i reset it to 800, and printed a 20x20x20 XYZ test cube... and it came out as perfect 20x20x20.... so looks like i nailed it and my Z screws are Trapezoid TR4. So consider this fixed.... now onto adding my second Z end stop.
; Drives
M569 P0 S0 ; physical drive 0 goes forwards
M569 P2 S1 ; physical drive 2 goes forwards
M569 P1 S1 ; physical drive 1 goes forwards
M569 P3 S0 ; physical drive 3 goes forwards
M569 P4 S0 ; physical drive 4 goes forwards
M584 X0 Y2 Z1:4 E3 ; set drive mapping
M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z800.00 E420.00 ; set steps per mm
M566 X900.00 Y900.00 Z12.00 E120.00 ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z180.00 E1200.00 ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z20.00 E250.00 ; set accelerations (mm/s^2)
M906 X800 Y800 Z800 E800 I80 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

Veti

@dingo007 said in Z axis off, Layers to tall.....:

So consider this fixed.... now onto adding my second Z end stop.

before you do please read
https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors

that is a better and easier solution

dingo007

@Veti thanks, ive read the document, though i dont see alot of information about dual Z endstops also
theres also this so im still a bit confused
https://duet3d.dozuki.com/Guide/Independent+Z+motors+and+endstop+switches/18

Veti

@dingo007 said in Z axis off, Layers to tall.....:

though i dont see alot of information about dual Z endstops also

the point is that you dont really need dual z endstop.
the bed is probed and the height is adjusted to truely level the bed.

if you really want dual z endstop you should update to rrf3
see
https://duet3d.dozuki.com/Wiki/Gcode#Section_M574_RepRapFirmware_Num_3

dingo007

... how does a single end stop provide a truey level bed.... it cant, it requires 2+ to level both sides.... as for using RR3 id like to once i get it all configured properly... and i looked at rr config for 3 and it doesnt appear to function.

Veti

@dingo007 said in Z axis off, Layers to tall.....:

how does a single end stop provide a truey level bed.

not by using an endstop, but a probe.

the dual endstop feature is only really supported in rrf3

there is a workaround in rrf2 by splitting the axis up during homing, but there is no point setting that up anymore in my opinion.