Hi fellow Reprappers. I just made my ReprapPro Mendel finished. I have used some aluminum pulleys instead of the plastic that came with it. My problem now is that when I move the X-axis 60mm forward with Pronterface, then move the shaft itself actually 69mm. Which parameter should I change in firmware and what is the right formula? Happy printing Torben https://reprap.org/forum/read.php?4,271772,271772#msg-271772 Thu, 12 Mar 2026 18:37:25 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?4,271772,272159#msg-272159 https://reprap.org/forum/read.php?4,271772,272159#msg-272159 uncle_bob Reprappers Tue, 26 Nov 2013 07:40:26 -0500 https://reprap.org/forum/read.php?4,271772,271979#msg-271979 https://reprap.org/forum/read.php?4,271772,271979#msg-271979
I did the same, I have got GT2 pullyes 20 tooth, and I had to adjust my STEPS PER UINT on the firmware as below

// default settings
// X, Y, Z, E steps per mm
#define DEFAULT_AXIS_STEPS_PER_UNIT {80.00, 80.00, 4000, 660}

You need to use the Josef Prusa calculater to workout yours
[calculator.josefprusa.cz]

Hope this info is useful.

Repdav]]> Repdav Reprappers Mon, 25 Nov 2013 19:04:55 -0500 https://reprap.org/forum/read.php?4,271772,271954#msg-271954 https://reprap.org/forum/read.php?4,271772,271954#msg-271954 uncle_bob Reprappers Mon, 25 Nov 2013 18:10:55 -0500 https://reprap.org/forum/read.php?4,271772,271867#msg-271867 https://reprap.org/forum/read.php?4,271772,271867#msg-271867
There is plenty of documentation about this. e.g i found this posting, but there are many others [www.matterhackers.com]

Try changing the values so that they are 60/69 times their current values then upload and measure again. In my experience I had to repeat a few times to get the value just right]]> rogerclark Reprappers Mon, 25 Nov 2013 14:53:13 -0500 https://reprap.org/forum/read.php?4,271772,271772#msg-271772 https://reprap.org/forum/read.php?4,271772,271772#msg-271772
I just made my ReprapPro Mendel finished. I have used some aluminum pulleys instead of the plastic that came with it. My problem now is that when I move the X-axis 60mm forward with Pronterface, then move the shaft itself actually 69mm. Which parameter should I change in firmware and what is the right formula?

Happy printing
Torben]]> vandborg Reprappers Mon, 25 Nov 2013 11:56:37 -0500