Printer Doesnt Home in Centre anymore

while setting the z probe offset i dont know what happened but now when i home with my BLTouch it thinks home is X145 y145 and not the centre of the bed
i have no idea what happened

im running
bltouch
skr 1.3
tmc 2209 drivers

You didn’t indicate whether it actually goes to the physical home location first, hitting the limit switches, and then to 145,145, which would be a Home Offset location, or whether it goes directly to 145,145 and never hitting the limit switches. I’m going to assume it’s going to the limit switches first…

Caveat #1: I have an E5Pro, not a CR-10, but I’ll have a go at this as it’s likely the same problem we experience. However, because the printers are different, it’s possible the menu structure is too, so if what I talk about isn’t there, don’t be too surprised.

Caveat #2: I just started a print before coming on here so I can’t access the appropriate menu system right now to verify what I’m about to type. It’ll be about 4 hours before it’s finished, so this is off the top of my memory.

The rotary button used on the control panel combines both a rotary encoder and a push-button switch. On paper they look like a good idea. In practice this introduces problems. The problem is that as you push the switch you may also rotate the encode which means that the menu item you actually select is not the one you were positioned on.

On the E5Pro, at least, in the Prepare menu, you get the option to Auto Home. We all use it frequently. Right below the Auto Home item is Save Offset (or Save Defaults, or something like that). So, say your print head is at 145,145 and you try to send it home; when you press the button to run the Auto Home function, the encoder rotates slightly and the function that is actually run is the next one down - Save Offset - which saves 145,145 as your new home offset. It will now go there every time it tries to home the print head.

The solution is to use the controller to manually move the print head to 0,0 and then select Save Offset to save 0,0 as the home position again.

Now, I’m out of my element here, but this gives you something to look up for a solution:

In case the printer is going directly to 145,145 without using the physical limit switches, there are some printers that have “soft limits”. My Ender 5Pro does not have this (that I know of) and I don’t know if it applies to the CR-10 at all, but if it does, here’s what it is and how it works, but not how to change it, because I have no idea.

A soft limit is a number stored in memory that tells the controller what the limits of travel should be. As the controller moves the print head, it changes the position count and compares it to the soft limit values. If they match, it stops moving. Effectively it’s the same thing as having a hardware limit switch. Similarly, when homing the printer, it can use the soft limit’s minimum values as the home position. If you have the soft limit’s minimum values set at 145,145 then that’s where it’s going to go.

As I say, I have no practical experience with this. I can see where a soft limit would be used to set a maximum value, but I don’t know how it can substitute for a physical limit switch. I mean, when you turn it on, how would it know where the print head actually is? More expensive machines have shaft encoders built into the stepper motors or attached to their shafts to provide the controller with an absolute position indication but E5’s and CR10s are dumber than that. I know this could happen in theory, but I have my doubts that that is what’s happening to you. Try my previous suggestion first.

i figured it out but thanks for the help

the probe offsets were reset to default values but since i have a bltouch instlalled when it went to x+10 y+10 it thought that the origin was still in the bottom left corner