# What is better? **URL:** \ **Category:** General Discussion\ **Created:** [March 28, 2022, 5:22pm UTC](https://klipper.discourse.group/t/what-is-better/2431 "2022-03-28T17:22:25Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Peurif](https://avatars.discourse-cdn.com/v4/letter/p/c57346/32.png) [@Peurif](https://klipper.discourse.group/u/Peurif)\ **Post date:** [March 28, 2022, 5:22pm UTC](https://klipper.discourse.group/t/what-is-better/2431/1 "2022-03-28T17:22:25Z")
Hi, I am starting to print and I have realized that the measurement on the Z axis is not correct, even for the first pieces that I have made, the nozzle at 35/40 mm hits the piece. I have seen that there are two methods to adjust this: 1- Method 1, changing the parameter [full\_steps\_per\_rotation] 2- Method 2, changing the parameter [rotation\_distance] Which of the two systems is more recommended? Thanks ---
**Author:** ![EddyMI3D](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/eddymi3d/32/1981_2.png) [@EddyMI3D](https://klipper.discourse.group/u/EddyMI3D)\ **Post date:** [March 28, 2022, 5:37pm UTC](https://klipper.discourse.group/t/what-is-better/2431/2 "2022-03-28T17:37:40Z")
> [@Peurif](#): > > 1- Method 1, changing the parameter [full\_steps\_per\_rotation] This one is hardware given and depends on the stepper motor you use. Usually it is 200 steps per rotation. This is set once when it is not 200. > [@Peurif](#): > > 2- Method 2, changing the parameter [rotation\_distance] This is the way to go. You have to calculate the way the stepper moves - in this case the z- axes - when the stepper motor makes one rotation. The exact amount of movement depends on the - most commonly - threaded rods you use. ---
**Author:** ![Peurif](https://avatars.discourse-cdn.com/v4/letter/p/c57346/32.png) [@Peurif](https://klipper.discourse.group/u/Peurif)\ **Post date:** [March 28, 2022, 6:09pm UTC](https://klipper.discourse.group/t/what-is-better/2431/3 "2022-03-28T18:09:57Z")
ok… The steppers motors, are 0.9 deg/step = 400 steps. The leadscrews of uses the printer are TR8\*4, in my config files, i can see: ```auto full_steps_per_rotation: 400 rotation_distance: 4 ``` I suppose that 1 revolution 4 mm. with this info, i print the calibration cube (20x20x20), and in Z measure 20x20x19,1 mm. New rotation\_distance = (4 x (19,1 / 20 ) = 3,82 → when motor does 1 rotation, z axis move 3,82. Are the maths ok? Thx ---
**Author:** ![EddyMI3D](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/eddymi3d/32/1981_2.png) [@EddyMI3D](https://klipper.discourse.group/u/EddyMI3D)\ **Post date:** [March 28, 2022, 7:05pm UTC](https://klipper.discourse.group/t/what-is-better/2431/4 "2022-03-28T19:05:05Z")
I would stick to > [@Peurif](#): > > `rotation_distance: 4` except the leadscrews has shrunken. These TR8 are quite precise. You are almost a millimeter off, so I would suggest to print a 30 mm height cube with an indent at 10mm, to take the bed squishing out of the calculation. You also can do this: 1. Move the printhead to a certain height, e.g 50 mm 2. Measure the distance to the bed. 3. Move the head another 100 mm up 4. Measure again 5. Subtract the first measurement. 6. Compare the result to the second movement ---
**Author:** ![Peurif](https://avatars.discourse-cdn.com/v4/letter/p/c57346/32.png) [@Peurif](https://klipper.discourse.group/u/Peurif)\ **Post date:** [March 29, 2022, 7:14am UTC](https://klipper.discourse.group/t/what-is-better/2431/5 "2022-03-29T07:14:15Z")
I take this opportunity to ask a question that has come up… since I am going to check [rotation\_distance] on the Z axis, I take advantage and also adjust it on the X and Y axes. But being a corexy… the parameter [rotation\_ distance]: - You mean a axis (X/Y)? - You mean an engine (X and Y movement? I ask, since it is a Corexy, when one motor rotates it moves diagonally, so perhaps we should put the calibration piece rotated 45º in Z. No? I find it more difficult to identify which motor is assigned to X and which to Y… ---
**Author:** ![Sineos](https://yyz2.discourse-cdn.com/free1/user_avatar/klipper.discourse.group/sineos/32/18_2.png) [@Sineos](https://klipper.discourse.group/u/Sineos)\ **Post date:** [March 29, 2022, 7:38am UTC](https://klipper.discourse.group/t/what-is-better/2431/6 "2022-03-29T07:38:37Z")
See > [@Dimensional accuracy problem](https://klipper.discourse.group/t/dimensional-accuracy-problem/2370/): > > Hi everyone. I have problem with my ender 3 v2 with dimensional accuracy. When I print an object X axis always smaller than Y axis in dimension. For example when try printing 30mm square with fillets at corners X axis around 29.75,Y axis around 29.95. I have no problem with my Y axis only in x axis. I checked printers frame all looks good and square, I could not find any skew. My belts are tightened at 9.5N with 76hz in X axis, 91hz in Y axis. Also when I check movement without printing X a…