Z position changes after homing

[Voron2.4Started2023]

Printer Model

Voron 2.4

Extruder Type

Clockwork 2

Cooling Type

Stealthburner

So I'm a newbie for building printers. I've been Printing for about 7 years but the Voron 2.4 is the first printer I've built. Everything is finished and basic tuning is done, I've got a couple of test prints done (Voron Cube which comes out great). But I've noticed that the Z position on the homing routine changes.

X homes fine, Y homes Fine, and then Z Travels to the correct position, But homes against the heater block instead of the nozzle.

I then move the print head to the far corner X = 20 Y = 20 Z =200, and then rehome and everything homes as it should no issues. I think it must be something to do with the belts but that's as far as I have got. I've Squared the gantry and the belts are at I think the right tension.

 

[NoGuru]

Can I assume you set the homing position in the printer.cfg?
Also what type of Z homing are you doing? endstop pin?

What does your Start_Print look like?

 

[Voron2.4Started2023]

Yes, I've set the home in the printer.cfg in the [safe_z_home] home_xy_position:237,350. and yes its the endstop pin, Its a formbot kit everything so far from the kit has been fine and I have seen others with the same problem.

Here is the Start_Print Macro

[gcode_macro PRINT_START]
# Use PRINT_START for the slicer starting script - please customise for your slicer of choice
gcode:
G32 ; home all axes
G90 ; absolute positioning
BED_MESH_CALIBRATE
G1 Z20 F3000 ; move nozzle away from bed

Im hoping its me missing something but all the issues I've had so far are because of the belts. (I missed a pully when I assembled everything). Ive replaced the belts with generic ones from amazon, which measure to be identical but they don't seems as flexible, but there's no noise or belt dust anywhere. But either way, i can't work out why the error stops once I've moved its again.

 

[NoGuru]

I would go through the initial startup docs again. It's odd that it would randomly just probe on the block.

Initial Startup

Voron Official and Community Documentation

docs.vorondesign.com

 

[Voron2.4Started2023]

OK, Problems Solved. I replaced the belts with a different set. And when I took the first set off and checked them for missing teeth and to feel if they were stretched. And yes I have a 100mm length that was stretched enough to feel a difference. Im not sure if it came like that or if it was me. But thanks for the Assistance