Wider Fan Shroud Hitting X Axis - What to do ?

[BlueWings172]

Hello

I have just installed a new Satsana fan shroud (https://www.thingiverse.com/thing:4787797/files) which is about 100mm in width compared to the 62mm of stock Ender 3 V2 shroud.

The printer does not realize that the printhead became much bulkier and sometimes slams into the right end of the X axis because there is no end-stop sensor on that side. This happens for example prior to each print during UBL mesh titling where printer probes the bed at 3 opposing points (I have G29 in my start G-code)

I have then set my X home offset to -10 and this allowed the printer to print the purge line without hitting the end of the X-axis where there is an end stop sensor. So that solved issues on the left end of the X Axis but not sure what to do to the right side?

Should edit something in the firmware ? or is there any setting I can change through the LCD?

If firmware changes are required, can I use the auto-compile service for that ? I don't have experience compiling firmware through MS Visual studio.

thanks

[BlueWings172]

@tititopher68-dev

Happy holidays!

Your explanation was essential in getting me solve this issue so thanks for that.

I tried to avoid it but I had compile firmware and followed your post.

Since my nozzle is inside the bed when the printhead is pressed against the X endstop switch, my X_MIN_POS has a positive value that I measured with calipers. I have set X_MAX_POS at 239 because around 240 the nut behind the gantry slams into X axis tensioner.

I initially had error after compiling saying: "Movement bounds (X_MIN_POS, X_MAX_POS) are too narrow to contain X_BED_SIZE" so then I calculated the X_BED_SIZE according to this formula: (X_MAX_POS - X_MIN_POS) >= X_BED_SIZE.

Now when I try to move the X axis from the screen, the minimum value I see now is 13 instead of 0 and the printhead no longer slams left and right during UBL mesh tilting. I made the illustration below to explain it. Hopefully this helps someone else.

Below are all the lines I needed to change in configuration.h

#define X_BED_SIZE 222
#define Y_BED_SIZE 226

#define X_MIN_POS 13
#define Y_MIN_POS 8

#define X_MAX_POS X_BED_SIZE + 17 // Extended max to allow the probe to reach more of the bed.
#define Y_MAX_POS Y_BED_SIZE + 8

#define NOZZLE_TO_PROBE_OFFSET { -49.5, -20, -2.86 }

I printed a test cube but it was not centered. It could be because I forgot to change my bed size in cura ? will try again.

Also BL Touch probe is a bit off center when homing.

I have noooo clue how setting Home Offset values on the screen affect homing position (X and Y homing position are identical despite offsets are different !?!) I change them both to 0.