Independently leveled Z axis Issue

mrenz999

I am having this same issue. It used to Level pretty close to perfect. Now it does the same as yours. It lifts the right, rear corner and lowers the left side of the bed. I have checked belt tensions, remeasured my z screw positions. Have had no success figuring it out.

3DPrintingWorld

@mrenz999 Oh, I wonder if we have the same problem or if its just a coincidence. What printer do you have, or is it a custom build?

Have you tired physically swapping two motors just to see if the results change?

martin7404

So today I made quite a few experiments chasing my problem with moving of the U carriage during printing with X.
A few days ago I tried to put both Y motors on ZA and ZB conectors , just to find that one of my Z connectors is not energizing the motor.
I ordered a new Duet wifi and while waiting today decided to try to move 3 Z motors on wifi and x,y,u on DUEX board.
So I put 3Z motors on P1,2,3 and the motor on 2 is not energized, then moved the motors to 0,1,2 and it is working , but center motor is inverted (2), So I make it to move in the right direction with inverted motor, but when G32 it is corecting wrong direction, I do not know why
then tried on 234 and 2 is not working, then defined this:

; Drives
M569 P2 S1                                 ; X physical drive 0 goes backwards
M569 P3 S1; Z
;M569 P3 S0
M569 P4 S0
;M569 P1 S0                                     ; Y right physical drive 1 goes backwards
;M569 P2 S1                                      ; Y left physical drive 2 goes forwards
;M569 P3 S1                                      ; U physical drive 3 goes forwards
M569 P1 S1                                     ; E1 physical drive 4 goes backwards
M569 P5 S0 ; X
M569 P6 S1 ; Y right
M569 P7 S0 ; Y left
;M569 P5 S1                                      ; Z left physical drive 5 goes backwards
;M569 P6 S1                                     ; Z center physical drive 6 goes backwards
;M569 P7 S0                                      ; Z right physical drive 7 goes forwards
M569 P8 S1                                      ; E2 physical drive 8 goes forwards
M569 P9 S1 ; U

M584 X5 Y6:7  Z0:3:4 U9 E1:8                     ; set drive mapping

and it is working like a charm . Ther is some kind of short on this board ,period. Now the movement of U with dial indicator when changin gY direction is 0.04 and X is 0.05

fcwilt

@martin7404

Do you ever turn the steppers or move an axis by hand when the power is off?

That can damage the driver chip connected to that stepper or steppers.

Frederick

martin7404

I am usually very careful and do hand movements with power on .
The thing is now it is working

fcwilt

@martin7404 said in Independently leveled Z axis Issue:

I am usually very careful and do hand movements with power on .
The thing is now it is working

You mentioned that a driver or two seemed to have failed which is why I made my post.

Glad to hear you got things sorted.

Frederick

martin7404

It is sorted in wierd way , new board is on the way
PS it is not sorted U is moving during printing with X even all the X,Yand U motors are now on DUEX

mrenz999

@3DPrintingWorld I have tried swapping motors. No difference. I have a BLV Mgn. So yes I built it. It's a custom with a 410x410 bed

3DPrintingWorld

@mrenz999 The BLV is very nice!
That's the part that throws me, how is it possible that you can switch the motors but it still corrects to the same plane....

I think I'm just going to have to bite the bullet and try a new boards, I'm running out of ideas.

fcwilt

@martin7404 said in Independently leveled Z axis Issue:

It is sorted in wierd way , new board is on the way
PS it is not sorted U is moving during printing with X even all the X,Yand U motors are now on DUEX

Well having the Z steppers on the Duex wasn't part of the problem in the first place.

Frederick

fcwilt

@3DPrintingWorld said in Independently leveled Z axis Issue:

@mrenz999 The BLV is very nice!
That's the part that throws me, how is it possible that you can switch the motors but it still corrects to the same plane....

I think I'm just going to have to bite the bullet and try a new boards, I'm running out of ideas.

How about doing G29 with just a 4 point grid covering most of the bed and posting a screen snap of the height map?

It's possible to level the bed as far as the 2, 3 or 4 points controlled by the steppers and still have twist to the bed.

A 4 point height map will reveal such twist.

Frederick

mrenz999

@3DPrintingWorld The interesting part is we are both having the same weird twist in the same direction. Very weird to me.

fcwilt

@mrenz999 said in Independently leveled Z axis Issue:

@3DPrintingWorld The interesting part is we are both having the same weird twist in the same direction. Very weird to me.

Hi,

Can you also create a 4 point height map covering most of the bed and post a screen shot of it here?

Frederick

mrenz999

@fcwilt Sure. I will do that in the next 15 - 20 mins

mrenz999

@fcwilt What is the correct procedure for getting a 4 point height map ? 410x410 Bed ? lol

fcwilt

@mrenz999 said in Independently leveled Z axis Issue:

@fcwilt Sure. I will do that in the next 15 - 20 mins

Great.

I have a MarkForged style printer with 3 Z steppers and even though the leveling appeared to work the 4 point height map still showed a "twist" along the X axis.

It turned out the the Y rails (left and right) were not in the same plane which gave the appearance of the bed being "twisted" - which it wasn't.

Frederick

mrenz999

Measuring the bed to nozzle it appears and is without question twisted. But if you tell me how to do a 4 point height map I will do one now.

fcwilt

@mrenz999 said in Independently leveled Z axis Issue:

@fcwilt What is the correct procedure for getting a 4 point height map ? 410x410 Bed ? lol

On my printer where X=0 and Y=0 is at the center of the 300 x 300 bed I used something like this:

M557 X-130:130 Y-130:130 P2:2 ; define 4 point mesh for G29

Your values will depend on the X and Y offsets of your probe and the min/max values of your X and Y axes. Just try to keep the probe area centered on the bed.

Frederick

mrenz999

@fcwilt

3DPrintingWorld

Thanks @fcwilt, think you finally helped me realize my issue. Only four points makes the map much easier to understand.

When I first ran the mesh the left back corner was really low. I have a glass plate on top of a sheet magnet. I am only using glass because I wanted to verify the bed was flat.
glass-w clips.png

I'm clipping down the bed in the back center left and front center right. I moved both clips to center right and reran the mesh and the low corner goes away!

Upon further inspection of the magnetic sheet shows small cracks where it starts to turn blue in the first map. I think these crack are causing the issue. I'll remove the magnet an put the glass directly on the bed tomorrow and give it a try.