RepRapPro Mendel, correct axis movement

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

Open configuration.h and find the default steps per unit and change the first and second parameters

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

Before you head into the firmware, you might as well check the X and Z axis as well. They don't interact with each other. Correcting them all at once is a bit less work than doing it one at a time.

Hi Torben,

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

I think if you go into the C code, you will find that the steps are integer numbers. Having decimal points in them may eventually confuse the firmware. More or less - an update comes out two years from now and things go nuts.