Geeetech

I am new to 3d printing but due to a very malfunctional Z axis, would like to replace my M8 z axis threaded rods for trapezoidal 8mm screws (1,5 mm screw thread).
Do i have to replace the firmware? Or is there a simpler way?
Does someone have any experience with this issue?
I am using Repetier as software.

You should change the value of Z motor step per mm
M8=1.25(2560)

@Maker, did you get this sorted yet?

[quote]replace my M8 z axis threaded rods for trapezoidal 8mm screws (1,5 mm screw thread).[/quote]
If you replace the M8 screw with a single start Tr8 leadscrew with the same pitch (1.25mm), you don't need to change the firmware. If you use a different pitch and start you will need to change the Z-axis step size in the config.h file before recompiling and uploading the modified firmware to the G2560 board.
If you use Repetier-Host as your printer monitor/controller, you can find a leadscrew calculator under the "tools" tab which will help with step size. Tr8 x 1.5mm is one of the options. The 'gear ratio selection' relates to the number of starts the leadscrew has. (the original M8 rod is single start) Take note when you're ordering a replacement!

Play Bonny!

Soadyheid.