Z axis calibration Hi, I'm trying to calibrate my mendel 90 but it isn't going well. If i want start printing, the z axis goes down en keep lowering even if the extruder is on the heatshield. Does anyone know how i need to solve that? Thank you 3design https://reprap.org/forum/read.php?292,293242,293242#msg-293242 Mon, 16 Mar 2026 13:48:10 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?292,293242,310009#msg-310009 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,310009#msg-310009 3Design Mendel90 Wed, 12 Feb 2014 12:26:08 -0500 https://reprap.org/forum/read.php?292,293242,299262#msg-299262 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,299262#msg-299262 3Design Mendel90 Wed, 22 Jan 2014 10:38:47 -0500 https://reprap.org/forum/read.php?292,293242,298826#msg-298826 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,298826#msg-298826
[www.youtube.com]
[www.youtube.com]
[www.youtube.com]

Yes, I have a Mendel90. I've found Nophead's documentation and these videos to demonstrate the GENERAL process of calibration helpful. I'm using RAMPS 1.4 so I've had to dig around the internet a little more to get closer to actually printing. I can't help much more than that.]]> Miterez1 Mendel90 Tue, 21 Jan 2014 16:11:03 -0500 https://reprap.org/forum/read.php?292,293242,296977#msg-296977 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,296977#msg-296977
Regards,
Neil Darlow]]> neildarlow Mendel90 Sat, 18 Jan 2014 08:36:29 -0500 https://reprap.org/forum/read.php?292,293242,296892#msg-296892 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,296892#msg-296892
i don't find the melzi in the marlin map.]]> 3Design Mendel90 Sat, 18 Jan 2014 04:55:59 -0500 https://reprap.org/forum/read.php?292,293242,296887#msg-296887 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,296887#msg-296887
Just drag that folder (the Melzi part) to "My Documents\Arduino\hardware" in Windows Explorer.The next time you next start Arduino the Melzi boards should be available.

Regards,
Neil Darlow]]> neildarlow Mendel90 Sat, 18 Jan 2014 04:40:25 -0500 https://reprap.org/forum/read.php?292,293242,296886#msg-296886 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,296886#msg-296886
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3Design
And what is the melzi folder?
The melzi folder is the folder that contains the hardware definitions for the melzi. It can be found in the marlin directory.

neildarlow has already explained it above:
[forums.reprap.org]]]> sometimesfood Mendel90 Sat, 18 Jan 2014 04:39:01 -0500 https://reprap.org/forum/read.php?292,293242,296855#msg-296855 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,296855#msg-296855 3Design Mendel90 Sat, 18 Jan 2014 03:10:31 -0500 https://reprap.org/forum/read.php?292,293242,296767#msg-296767 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,296767#msg-296767 nophead Mendel90 Fri, 17 Jan 2014 20:08:37 -0500 https://reprap.org/forum/read.php?292,293242,296657#msg-296657 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,296657#msg-296657
i cant select this board, it is not in the list.]]> 3Design Mendel90 Fri, 17 Jan 2014 15:19:38 -0500 https://reprap.org/forum/read.php?292,293242,295990#msg-295990 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295990#msg-295990
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3Design
If i move my z axis 50 mm with pronterface moves it 62,50mm.
Do i need to adjust the 200 to 128?

No, the change of the divisor from 1 to 1.25 in the expression will correct that for you.

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3Design
when i try to upload the firmware i get this eror code:

error oops! make sure you have sanguino selected from the tools ->boards menu

That is my fault, I should have included in my inital Ardiuno set-up list the following:
  • From the "Tools|Serial Port >" menu choose your COM port
  • From the "Tools|Board >" menu choose "Melzi W/ ATmega1284p 16mhz"
It will then upload correctly.

Regards,
Neil Darlow]]> neildarlow Mendel90 Thu, 16 Jan 2014 15:32:04 -0500 https://reprap.org/forum/read.php?292,293242,295984#msg-295984 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295984#msg-295984 3Design Mendel90 Thu, 16 Jan 2014 15:27:28 -0500 https://reprap.org/forum/read.php?292,293242,295961#msg-295961 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295961#msg-295961
error oops! make sure you have sanguino selected from the tools ->boards menu]]> 3Design Mendel90 Thu, 16 Jan 2014 14:56:15 -0500 https://reprap.org/forum/read.php?292,293242,295955#msg-295955 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295955#msg-295955 Do i need to adjust the 200 to 128?]]> 3Design Mendel90 Thu, 16 Jan 2014 14:46:02 -0500 https://reprap.org/forum/read.php?292,293242,295948#msg-295948 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295948#msg-295948
// default settings
#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,200*16/1,E_STEPS_PER_MM} // Mendel90 with Wades and Stoffel15 bolt

The expression 200*16/1 represents the number of steps per mm for the 1mm pitch threaded rod.

You need to change this expression to 200.0*16.0/1.25 which is the value required for a 1.25mm pitch threaded rod.

I am correct in assuming your machine is actually the "sturdy" (or wooden frame) variant?

N.B. I am being technically correct here in modifying the expression to floating point. The #define is used to initialize an array of float values.

Regards,
Neil Darlow]]> neildarlow Mendel90 Thu, 16 Jan 2014 14:32:51 -0500 https://reprap.org/forum/read.php?292,293242,295894#msg-295894 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295894#msg-295894 3Design Mendel90 Thu, 16 Jan 2014 13:17:47 -0500 https://reprap.org/forum/read.php?292,293242,295599#msg-295599 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295599#msg-295599
You must set the height at which this switch operates in the Marlin firmware so it can calculate the zero position of the Z axis. If this value is set too large the zero position will be under the bed surface and if it is set too small the zero position will be above the bed surface.

The Build Manual advises that you should place a known-size object on the bed and nudge the print head downwards until the nozzle just touches the top surface of the object. You can then ask the firmware where it thinks Z is (M114) and use the known-height of the object and this value to determine the amount of adjustment to Z height that is required.

If, for example, your object is 20mm high and M114 tells you the nozzle is at 21mm then you need to add 1mm (minus 0.2mm to allow for nozzle expansion - so 0.8mm) to the firmware Z height value to lower the reported position. You then reload the firmware with this new Z height value and repeat the test to assure that M114 returns the correct height (plus 0.2mm).

This procedure, along with Extruder steps per mm calibration, is necessary to get you near the correct first layer height. Later you will measure the first layer thickness of a real print and adjust the Z height value again so that the first layer height is accurate.

Regards,
Neil Darlow]]> neildarlow Mendel90 Thu, 16 Jan 2014 03:07:24 -0500 https://reprap.org/forum/read.php?292,293242,295561#msg-295561 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295561#msg-295561 3Design Mendel90 Thu, 16 Jan 2014 01:28:31 -0500 https://reprap.org/forum/read.php?292,293242,295361#msg-295361 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295361#msg-295361
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3Design
I've adjust the value from each motor, is there anything else that i need to adjust?

The only steps/mm value you should have changed should be the Z one (for the 1.25mm threaded rod pitch). After that you need to follow the Calibration section of the Build Manual which will walk you through the Z height and Extruder steps/mm setting procedure.

The Mendel90 Build Manual is here in PDF format. This is for the Dibond model but the testing and calibration sections are still relevant.

Regards,
Neil Darlow]]> neildarlow Mendel90 Wed, 15 Jan 2014 17:07:30 -0500 https://reprap.org/forum/read.php?292,293242,295332#msg-295332 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295332#msg-295332 3Design Mendel90 Wed, 15 Jan 2014 16:35:03 -0500 https://reprap.org/forum/read.php?292,293242,295304#msg-295304 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295304#msg-295304 3Design Mendel90 Wed, 15 Jan 2014 16:05:42 -0500 https://reprap.org/forum/read.php?292,293242,295286#msg-295286 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295286#msg-295286
  • Open your web browser and go to [github.com]
  • Click on the "Download ZIP" button
  • Copy the "Marlin-Marlin_v1\Marlin" folder from the zipfile to "My Documents\Arduino"
  • Copy the "My Documents\Arduino\Marlin\Melzi" folder to "My Documents\Arduino\hardware"
    • Use the following method to modify the firmware:
    1. Start Arduino and load Marlin from the "File|Sketchbook...|Marlin" menu entry
    2. Locate Configuration.h and make your changes
    3. Save Configuration.h and click the Upload button to compile and upload to the printer
    Regards,
    Neil Darlow]]>     neildarlow Mendel90 Wed, 15 Jan 2014 15:26:25 -0500     https://reprap.org/forum/read.php?292,293242,295275#msg-295275 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295275#msg-295275
    How can i open a github file in arduino?]]>     3Design Mendel90 Wed, 15 Jan 2014 15:04:09 -0500     https://reprap.org/forum/read.php?292,293242,295241#msg-295241 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295241#msg-295241 Configuration.h]]> neildarlow Mendel90 Wed, 15 Jan 2014 13:43:38 -0500 https://reprap.org/forum/read.php?292,293242,295140#msg-295140 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,295140#msg-295140 does anyone know which file this is?
    [www.youtube.com]]]>     3Design Mendel90 Wed, 15 Jan 2014 11:24:49 -0500     https://reprap.org/forum/read.php?292,293242,293648#msg-293648 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,293648#msg-293648 3Design Mendel90 Sun, 12 Jan 2014 14:29:05 -0500 https://reprap.org/forum/read.php?292,293242,293468#msg-293468 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,293468#msg-293468 lazzymonk Mendel90 Sun, 12 Jan 2014 08:16:24 -0500 https://reprap.org/forum/read.php?292,293242,293466#msg-293466 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,293466#msg-293466
    After that follow the calibration instructions in the manual for the kit (on Github).]]>     nophead Mendel90 Sun, 12 Jan 2014 08:14:29 -0500     https://reprap.org/forum/read.php?292,293242,293460#msg-293460 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,293460#msg-293460 3Design Mendel90 Sun, 12 Jan 2014 07:51:33 -0500 https://reprap.org/forum/read.php?292,293242,293358#msg-293358 Re: Z axis calibration https://reprap.org/forum/read.php?292,293242,293358#msg-293358 lazzymonk Mendel90 Sun, 12 Jan 2014 03:54:34 -0500