Running a G28 X and X 0 always end up 4mm apart

Hello,

I am in the process of replacing the Crealtiy 2.1 mainboard in my CR10S with a SKR 1.3 running BTT 2209 v2.1's in UART mode. I have separated out the second Z stepper onto the E1 connector but have reused all the main electronic components and ends stops. I have a Microswiss Hotend using the stock thermister and heater. The system is all running form the original power supply (12V). I have also moved the hotend fan onto the E1 mosfet so I can use the 50C auto-fan and am using the BLTouch v3.1 to do bed levelling and z-stop.

It am still very much calibrating and the guts of it are splayed out across my workbench but I have managed to get it to print twice so far but I have noticed that when it runs my post print gcode to present the work piece and move the hotend out of the way. It slams into the X endstop. After some investigation I can repeatedly get it to do this by homing X with G28 X, then moving the head away and back with say a G1 X 150, and then G1 X0. It seems when it homes the position of X is always 4mm the wrong side (left) of where X home is.

I though maybe it wasn't moving accurately but as long as I never try going lower than X 4 I can get it to move at crazy speeds back and forth without ever going out of position so it doesn't seem to be that. I thought it might be the microswitch so I replaced that.

I can't seem to see the wood through the trees if there is a firmware setting I have messed up on or if this is some form of debounce problem. Anyone had the same problem or point me in the direction of it could be.

Much appreciated

Copter

what does #define X_MIN_POS say? It should be <= 0

Yeah it was staring me in the face the whole time, I realised between the Marlin 1.1.x and 2.x.x example configs there has been some changes made to the bed sizing and home points. I noticed the bed isn't defined as 300x300 anymore with a comment to the fact home is at 4mm.

This combined with my custom x endstop mount meant the tweaks I was making with the hardware was bumping into the example config changes and also my mish mash of uplifting config stuff from 1.1.x.

So just me being a complete muppet, compiled and all working fine now.

Thanks much appreciated!