Updated to Cura 5.2.1 Having coordinates problems?

[betowars 0]

Hi! i had to make a clean install of windows as i was replacing my SSD with a M.2.

Installed the new version of Cura and started having this problem with the coordinates.

 

It doesnt respect the place i put the piece to print in the Build Plate, When the print starts it does it at x=0 for the start point of the print, if there is something more to the left it sounds like the printer tries to go to negative values in X, as far as I can see there is no problem with the axis Y. I place it at the other end of the plate (as seen on the screenshot) and it prints it 4 cm from the left edge

 

I noticed that although the Origin is declared in the lower left corner, the coordinates in Cura appear from the center

 

In Start G-Code i removed X0.0 from "perform wipe and prime" because it was doing something similar, after homing it was trying to go negative in X axis

Thanks for all the help you can give me

[ahoeben 1,955]

5 hours ago, betowars said:

I noticed that although the Origin is declared in the lower left corner, the coordinates in Cura appear from the center

 

The axes indication in the viewport is an indication of where you have told Cura that the origin is in the firmware. Cura has its own internal coordinate system that has its origin in the center of the buildplate.

 

The "origin at center" setting has nothing to do with the coordinates in Cura. It is about what you are telling Cura is the origin on your printer. For ~95% of all normal, orthogonal printers, the origin in the firmware is in the corner of the bed. But for eg delta-style printers, the origin is in the center. It could be that your printer firmware is one of the exceptions, and that the "origin at center" option needs to be checked for your printer.

[betowars 0]

12 hours ago, ahoeben said:

 

The axes indication in the viewport is an indication of where you have told Cura that the origin is in the firmware. Cura has its own internal coordinate system that has its origin in the center of the buildplate.

 

The "origin at center" setting has nothing to do with the coordinates in Cura. It is about what you are telling Cura is the origin on your printer. For ~95% of all normal, orthogonal printers, the origin in the firmware is in the corner of the bed. But for eg delta-style printers, the origin is in the center. It could be that your printer firmware is one of the exceptions, and that the "origin at center" option needs to be checked for your printer.

It's getting very confusing for me, I tried to use another slicer and the same error occurred, the piece was printed in the wrong place only on the X axis. , but I am also sure that I was printing benchys after the printer was already working. This error resulted from formatting my PC, that's why I thought it would be something that changed in Cura

 

Very confusing, for now I will try to find an error in the firmware, if you can point me to what to look for, I have an idea but I don't usually work much in Marlin, only when there is an error or the printer I need some change.

Thank you very much for your response

[gr5 2,189]

First I would home the machine and then send commands for the machine to move to 0,0 such as:

G1 X0 Y0

 

 

Then I would move the head just a little to see which way it moves

G1 X10 Y10

 

Then if the first point was front left corner and second was moving towards the center I would try

 

G1 X175 Y120

 

If the center is around 175, 120 then I think the printer is working fine where the center is around 175,120.  But perhaps not?  Perhaps your printer isn't really 350 wide and 240 deep?  Perhaps it's much smaller and that is the problem - in that you entered the wrong values into cura machine size.

 

If the above commands worked perfectly then I don't understand because the gcodes you posted above are well within those values.

[betowars 0]

1 hour ago, gr5 said:

First I would home the machine and then send commands for the machine to move to 0,0 such as:

G1 X0 Y0

 

 

Then I would move the head just a little to see which way it moves

G1 X10 Y10

 

Then if the first point was front left corner and second was moving towards the center I would try

 

G1 X175 Y120

 

If the center is around 175, 120 then I think the printer is working fine where the center is around 175,120.  But perhaps not?  Perhaps your printer isn't really 350 wide and 240 deep?  Perhaps it's much smaller and that is the problem - in that you entered the wrong values into cura machine size.

 

If the above commands worked perfectly then I don't understand because the gcodes you posted above are well within those values.

 

There is my problem!, in the first step, when home the machine this is what it does:

1 - Z lifts normally 10mm or less

2 - X displaces left, normally until reaches origin sensor

3 - Y displaces up, normally to orgin sensor

4 - Both X and Y try to move to center but only Y reaches the mid point. X moves a small distance, maybe 10mm, then another 10 when y ends moving.

5 -  To that point screen displays that the Extruder is at the center X = 175, Y = 125. That is why the Start G-code sequence was hitting X carriage an the beginning.

 

Now... why is that happening? hahaha!

 

I dont see X having mechanical problems to move, if i place the piece to print in the right mid of the plate it works fine

Ill try to attach a video of home sequence

[betowars 0]

 

Here it is 🙂

Thank you for the help

[ahoeben 1,955]

Check if the X axis is slipping. It seems that the last move is a fair bit faster than the other moves, and it could be that eg one or more pulleys is loose enough that it slips when moving this fast.

[gr5 2,189]

I'm not familiar with this style of printer.  This looks familiar from someone else's post.  I think @GregValiant might understand this MUCH better than me.  However I expected it to home to 0,0 (front left corner) and just stop.  Why would it move at all afterwards? 

 

Did you home using a command on the printer?  Does your printer even have a controller to control it?  Or is does it print only through USB?  Do you have the ability to control the printer without using a gcode file?  Either through software like pronterface, or cura, or using some kind of controller on the printer?

 

Do you know how to type in a gcode and watch the printer respond, and then type in a new gcode and watch the printer respond?  That was what I was suggesting above.  One gcode at a time.  Watch what the printer does.  See where the confusion is.

 

I suspect the problem is that the printer is nowhere close to 350mm wide.  To my eye that printer is MUCH smaller.  But I really can't tell.

 

[GregValiant 1,287]

Hello all.

It would be helpful to know the Make, Model, and gcode "Flavor" of your printer.  I don't recognize it off hand.

 

On your printer's LCD - within the menus are there commands for "Set Home Offset" and "Save Settings" (could be called "Store Settings")?

I ask because this looks to be a problem with your Home Offset location and if those commands are available then it should be a quick fix to adjust it.  If they aren't then its a bit more complicated but doable.

 

As @gr5 mentioned, the typical situation would be to stay against the switches after auto-homing.  That move to 175,125 and then being only 25mm or so from the left edge is really odd.

Does it have a USB port and/or an SD card slot?

 

 

 

 

[betowars 0]

3 hours ago, gr5 said:

I'm not familiar with this style of printer.  This looks familiar from someone else's post.  I think @GregValiant might understand this MUCH better than me.  However I expected it to home to 0,0 (front left corner) and just stop.  Why would it move at all afterwards? 

 

Did you home using a command on the printer?  Does your printer even have a controller to control it?  Or is does it print only through USB?  Do you have the ability to control the printer without using a gcode file?  Either through software like pronterface, or cura, or using some kind of controller on the printer?

 

Do you know how to type in a gcode and watch the printer respond, and then type in a new gcode and watch the printer respond?  That was what I was suggesting above.  One gcode at a time.  Watch what the printer does.  See where the confusion is.

 

I suspect the problem is that the printer is nowhere close to 350mm wide.  To my eye that printer is MUCH smaller.  But I really can't tell.

 

The printer is a Tevo Black Widow, has a 8 bit board, MKS 1.4. The original for the printer, replaced drivers with 2130s, Screen+SD for a mini12864 from Bigthreetech, and an orbiter extruder.

Print area is supposed to be X400 x Y250 x Z250.

I did what you told me, send Gcodes manually and saw the problem in the fist step, in the home process, X axis has no physical problem to move, but fails when G28 commando tries to home Z axis, its programmed to go center i think because the printer originally had a BL Touch. 

I wanted to modify what it does when i home Z, if i try to home Z only with G28 it does all the axis, X an Y can home alone but not Z, as a temporary fix i will tell the printer in the Start G-code to home X after Z, to have the real coordinates

[betowars 0]

2 hours ago, GregValiant said:

Hello all.

It would be helpful to know the Make, Model, and gcode "Flavor" of your printer.  I don't recognize it off hand.

 

On your printer's LCD - within the menus are there commands for "Set Home Offset" and "Save Settings" (could be called "Store Settings")?

I ask because this looks to be a problem with your Home Offset location and if those commands are available then it should be a quick fix to adjust it.  If they aren't then its a bit more complicated but doable.

 

As @gr5 mentioned, the typical situation would be to stay against the switches after auto-homing.  That move to 175,125 and then being only 25mm or so from the left edge is really odd.

Does it have a USB port and/or an SD card slot?

 

 

 

 

Hi thank you for the help Greg, just posted another response to Gr5 with some answers to those questions, flavor i think is marlin, or that is what it says in the gcode Screen capture i took, it has home offset and save settings, but oddly "save settings" from the screen doesnt work, so i send a M500 code.

has a USB and SD card slot.

[gr5 2,189]

27 minutes ago, betowars said:

it has home offset and save settings, but oddly "save settings" from the screen doesnt work, so i send a M500 code.

Interesting!  After the homing procedure is over do a:

G1 X0 Y0

and make sure it goes to the front left corner.  It doesn't matter where the G28 leaves the Y axis as long as when you do this gcode it goes to the front left corner.

[betowars 0]

55 minutes ago, gr5 said:

Interesting!  After the homing procedure is over do a:

G1 X0 Y0

and make sure it goes to the front left corner.  It doesn't matter where the G28 leaves the Y axis as long as when you do this gcode it goes to the front left corner.

 

Hi! at least every time i do changes from the screen and use save settings it doesn't do it haha

I put that second G28 only for X in my Start G-code and solved my Z axis homing problem temporarily, its printing in place and without problem (3.5 hours print), still i dont see it as a solution per se.

I`ll try your suggestion when it finish the print 🙂 Thank you!.

I suppose they exist different home sequences and i need to change the one my firmware is calling with G28. I just dont know how 😞 

[GregValiant 1,287]

Yea, that will work.  "Save Settings" might only work if changes have been made(?).  The M500 should always work.

Within Cura - the Cura coordinate system relating to the model has it's origins at the middle of the build plate so as far as setting up a slice or arranging models goes, the numbers you see will relate to the mid-point of the build plate.

Then, when Cura creates the gcode, those coordinates are translated to the Origin Point in the Machine Settings (either Center Origin which would require no translation, or for most printers to the left front corner).  That's what causes the most confusion.

 

OK time to fix this:

Get a tape measure and measure the actual Width (X) and Depth (Y) of the bed.  For this example let's say it measures 350 wide by 250 deep.

1. Subtract 5 from each number to create a 2.5mm safety border around the periphery of the bed.
2. Go into Cura and enter those new numbers (Ex: X=345 x Y=245) into the Machine Settings as your Width(X) and Depth(Y).
3. Back on the printer, Auto-Home the print head.
4. Move the Z up ~5mm.
5. Move the X until the nozzle is 2.5mm in from the left edge of the print surface.
6. Move the Y until the nozzle is 2.5mm in from the front edge of the print surface.
7. Drop the Z back down to "0".
8. On the LCD select "Set Home Offsets" and then "Save Settings" (or send M500).
9. On the LCD move the Z up again and move the X to 172.5 and the Y to 122.5.  The nozzle should be in the middle of the print surface.  If it isn't let us know.
10. Next test is for max size.  On the LCD send the nozzle to X345 Y245.  It should be 2.5mm in from the right edge and 2.5mm in from the back edge of the build surface.  If it comes up short then additional adjustments will need to be made.  By adjusting the Home Offset location you can get a print that was centered in Cura to print in the exact center of the build surface.

 

[gr5 2,189]

23 hours ago, betowars said:

I put that second G28 only for X in my Start G-code and solved my Z axis homing problem temporarily,

I don't know why you think that is a temporary solution - it sounds like you are describing an excellent permanent solution?  What am I missing?

[betowars 0]

1 hour ago, gr5 said:

I don't know why you think that is a temporary solution - it sounds like you are describing an excellent permanent solution?  What am I missing?

 i suppose im not entirely happy with it, as its something wrong with G28, but yeah, i can print now.

For my next problem will it be best to open a new thread isnt? My benchy shows 2 issues

under extrusion (i have the suspicion that the printer did not stored my changes when i fixed steps in Extruder motor, expected 10mm and moved 5.7mm)

  and a problem with retraction, i think

[betowars 0]

On 11/27/2022 at 1:54 PM, GregValiant said:

Yea, that will work.  "Save Settings" might only work if changes have been made(?).  The M500 should always work.

Within Cura - the Cura coordinate system relating to the model has it's origins at the middle of the build plate so as far as setting up a slice or arranging models goes, the numbers you see will relate to the mid-point of the build plate.

Then, when Cura creates the gcode, those coordinates are translated to the Origin Point in the Machine Settings (either Center Origin which would require no translation, or for most printers to the left front corner).  That's what causes the most confusion.

 

OK time to fix this:

Get a tape measure and measure the actual Width (X) and Depth (Y) of the bed.  For this example let's say it measures 350 wide by 250 deep.

1. Subtract 5 from each number to create a 2.5mm safety border around the periphery of the bed.
2. Go into Cura and enter those new numbers (Ex: X=345 x Y=245) into the Machine Settings as your Width(X) and Depth(Y).
3. Back on the printer, Auto-Home the print head.
4. Move the Z up ~5mm.
5. Move the X until the nozzle is 2.5mm in from the left edge of the print surface.
6. Move the Y until the nozzle is 2.5mm in from the front edge of the print surface.
7. Drop the Z back down to "0".
8. On the LCD select "Set Home Offsets" and then "Save Settings" (or send M500).
9. On the LCD move the Z up again and move the X to 172.5 and the Y to 122.5.  The nozzle should be in the middle of the print surface.  If it isn't let us know.
10. Next test is for max size.  On the LCD send the nozzle to X345 Y245.  It should be 2.5mm in from the right edge and 2.5mm in from the back edge of the build surface.  If it comes up short then additional adjustments will need to be made.  By adjusting the Home Offset location you can get a print that was centered in Cura to print in the exact center of the build surface.

 

 i hope i can try it later today, thank you!!

[gr5 2,189]

yes that's underextrusion.  I'm confused - did you do an extrusion test to see how much it extrudes?  You should move the filament an exact known amount such as 10mm or 100mm and then measure how far it moves.  Then take the ratio.  Take your existing steps/mm and then multiply or divide by the ratio (to make it move more or less) to get the new steps/mm value.

 

99% of printers don't need to be calibrated for extrusion steps/mm.

 

[GregValiant 1,287]

"99% of printers don't need to be calibrated for extrusion steps/mm." 

 

Uh-Huh.

When your printer is from the bottom of the barrel you calibrate the E-steps.  100% of Creality printers (and 100% of their clones - Tevo, Anet, Geeetech, et al) must have the E-steps calibrated.  (And then someone talks the owner into using a single wall "flow calibration cube" and they end up horribly under-extruding anyway.)

 

So @betowars there are some things you can check to make sure Cura and the printer are on the same page.  Generally though - if it is a mismatch between Cura and the printer (like one set to Volumetric and the other to regular) it's a lot worse than what you have there.

There are a bunch of videos out there on calibrating the e-steps.  You should be able to change the setting from the LCD / control panel.  I do it as part of my periodic maintenance routine.  Once they are set though then it's as @gr5 explained...they don't really change.

 

 

[betowars 0]

@gr5, @GregValiant

 

I guess my printer is at 1%, I started to suspect the under extrusion because:

• The prints were showing me that problem.
• The extruder stepper was making a different sound than it usually does, I was holding the filament while it was being fed and I noticed that it was moving very slowly.
• Having recently changed the extruder also made me doubt, the original Tevo printer stepper has a gearbox.

In the end, it changed from 800 steps to 1388, which was the result I obtained to compensate for the 5.7mm movement, against the expected 10mm.
 

The benchy looks very good but other impressions make me see that perhaps there is too much material, it accumulates a bit on short trips.

I see accumulated material at the base, I will try to compensate it by lowering the value of "flow" a little.

Edited December 5, 2022 by betowars

[GregValiant 1,287]

In that last image the print on the left is MUCH better.

Benchys are good for some things but for checking flow I find that a large flat area inspected with a magnifying glass (or microscope) works best.

If you bring a flat topped calibration cube into Cura you can scale it to 1mm in the Z and 100mm square.  Set the "Top/Bottom" line directions to [0,90].

As it prints you can see how it is going down and adjust the flow from the LCD tuning menu during the print.  A close inspection can tell you how you are doing.

[gr5 2,189]

Don't tune on the bottom layer though.  The bottom layer depends too much on your leveling.  So you can play with tuning on the bottom layer but think of that as practice.  The real tuning happens on a higher layer.

[GregValiant 1,287]

Thanks @gr5 I didn't make that clear.  Top layer for a close inspection.  The first couple of layers may be still suffering from trying to compensate for any over or under extrusion of the initial layer do to leveling variances.