Print not centered on bed

[Leea 0]

I am using Cura 4.4.0 with an Ender-3. This is the first time I am trying to print something close to bed size. I am printing 200mm long (not too wide) and my bed is 220mm. The actual plate is 235mm. In the slice it looks centered on the bed but when I print it is real close to the near edge, less than 5mm. That means the far edge is 30mm away instead of the 17 it should be. It lost adhesion and crashed the print. If I move the zero location of the bed the head won't clear the bed on start up resets. Why is that and how do I center it.

Lee

 

[ShopGeezer 2]

Hi.  I have the same problem with a Crealty CR20.  It has a 220mm square build surface. For the first time on a large print I noticed that it is printing really close to the front edge.  When I Autohome the print head the nozzle is about 4 mm forward of the build plate. The problem is the rear limit switch. It allows the build plate to move too far backwards when you do an Autohome. Manually moving the build plate forward to where I want it leaves the rear stop about 5mm forward of the limit switch. I loosened the mounting bolts on the limit switch to see if it would slide forward but it is not adjustable. So my only solution is to move my build surface as far foward as possible using the paper clips. This is only a problem for large prints that are close to the size of the build plate. Most of my prints are smaller. I have a question about this in to my vendor but no response yet. 

 

 

[Leea 0]

I forgot to mention that if I try to print something full size it will of course fall off the edge of the bed. I would like to know if you find anything.

Lee

 

[Jaymeson 0]

Bump your machine setting bed size to the actual build plate size. It's dividing your current settings by half when it's homed to find center. I had to increase mine from 220 x 220 to 235 x 235. Also, uncheck "Origin at Center" if it is.

[TWIISTED 0]

I have just noticed this issue in my slicer aswell on the latest version of the cura, I never suspected this to be an issue but I have never untill now needed to print the full size of my build plate, I have the ender 3 firmware set to 235, cura set to 220 so that it gives me some wiggle room, but I noticed that the prints are pushed more closer to the front and to the left slightly they are never equal on each side. I use the BLTouch aslo not sure if that is an issue. But does anyone know the fix for this without setting to 235 that way you still have that wiggle room available. 

[gr5 2,240]

Not really.  The smaller you tell cura the bed is, the more cura will push your part to the front left corner.  Cura divides what you tell it is the bed size by 2 and Cura considers that the "center".  So maybe only have a 1mm margin instead of a 15mm margin?  Or just tell Cura the truth.  It will not go beyond what you tell it.

[GregValiant 1,361]

Ya know @gr5 this has come up so many times.  Eventually we have to hit on an explanation that people can read and understand the first time.  I'm going to give it another try.

 

There are two build plates.  There is the virtual one in Cura that you've made 220 x 220.  There is the real build plate on the printer that is 235 x 235.

As Gr5 explained, the bed "X" divided by 2 and the bed "Y" divided by 2 gives the midpoint.  But aligning the "virtual" build plate midpoint to the "Real" build plate midpoint is the main function of the Home Offset setting.  Moving the Home Offset position moves the "virtual" build plate around on the "Real" build plate.

 

You want to center your 220 x 220 Cura build plate on your Ender's 235 x 235 build plate.  235 - 220 = 15 and so a 7.5mm safety zone on the left, right, top and bottom is what will align the Cura build plate to the Ender's build plate.

1. Put a piece of painters tape on the printer build plate near the left front corner.
2. Measure 7.5mm from the left edge of the build plate and 7.5mm from the front edge of the build plate and mark the tape with an X at that location.
3. Auto-Home the printer.
4. Using the LCD knob - Move the Z up 2 or 3mm.
5. Move the X and Y and position the nozzle directly over the X you made on the tape.
6. Remove the tape.
7. Drop the Z back down to 0.
8. On the LCD click on the "Set Home Offset" command (on my Ender it's in the "Prepare" menu).
9. Also on the LCD click on the "Store Settings" command (on mine it's under the "Control" menu).
10. Move the Z up again and move the X to 110 and the Y to 110 and I betcha that nozzle is right in the middle of the build plate.

When you Auto-Home the printer you will see that the X and Y location on the LCD are your Home Offset numbers.  They will likely be negative because the Auto-Home location is in relation to the Home Offset location which is 0,0,0.

 

 

 

 

Edited December 2, 2022 by GregValiant

[gr5 2,240]

To make things more complicated, The X and Y travel does not always match up with the bed itself.  In other words the nozzle may not be able to reach all 4 edges.  Or it may be able to travel beyond some of the edges of the bed.  And for dual nozzle print heads the printable area is often different if both nozzles are used.