In order to make the calibration as accurate as possible, you'll need to bring both the heated bed and the hot end to operating temperature. Set the Extruder temperature to 190C and the Bed temperature to 55C just as you did for setting the Z height.
Open the EEPROM editor and check the values shown below. If the Diagonal Rod Length parameter isn't set to 290.8, please change it to that value. The starting position for the Horizontal Radius is 144.
Fig. 2.4-9: Diagonal Rod & Horizontal Radius settings.
Make sure you save your changes before you move on.
In order to help you calibrate the Rostock MAX v2, SeeMeCNC has created a neat video that illustrates the entire process from beginning to end. In the video they're using the SeeMeCNC Orion printer, but the technique is the same for the Rostock MAX v2. When you see reference in the video to running the “TOWER.GCO” file, you'll instead click on the Tower Cal button that you just created the macro for. They're the same thing, just executed differently.
https://www.youtube.com/watch?v=g3CqWxTcV38
When you click on the Tower Cal button, it will execute the script you just entered. The script will move the nozzle to 0.2mm above the center of the build plate and pause for five seconds. It will then move to the X tower, then the Y tower, then the Z tower, and finally will return to center.
You may notice an odd “arc” motion as the nozzle travels from point to point. This is a mathematical phenomenon within the firmware and won't affect your calibration. You can safely ignore it.
Fig. 2.4-10: Nozzle at the center, 0.2mm above the glass.
2 – Installing MatterControl and Calibrating the Printer - 32
Rostock MAX v2 User's Guide
As the script runs, your focus should be on the nozzle where it pauses. You want to compare the gap at the tower base to the gap at the center.
If the nozzle at the tower base is higher at the pause point in comparison to the center, you'll want to turn the screw for that tower's end-stop counter-clockwise. Think “Turn Left to Lower”.
If the nozzle at the tower base is lower at the pause point in comparison to the center, you'll want to turn the screw for that tower's end-stop clockwise. Think “Turn Right to Raise”.
Repeat this process for each of the three axes. You can adjust a single axis at a time, or you can do two or all three. Doing all three at once may make you crazy unless you're a good juggler. Set the Z height and Tower Cal macro each time you make a change to an end-stop screw.
When you're done, you need to re-set the Z height as it will have changed due to the calibration process. Once you've re-set the Z height, run the Tower Cal macro again. Pay close attention to the distance between the nozzle and the glass bed.
If from the center position, the nozzle goes down toward the glass at all three towers, you'll need to change the Horizontal Radius value in the EEPROM. Open up the EEPROM table editor and scroll down until you see the field marked below.
You'll want to raise this figure by 0.2. Run the Tower Cal macro after each change to check the effectiveness of the change.
If from the center position the nozzle goes up from the glass at all three towers, you'll want to lower the Horizontal Radius by 0.2. Run the Tower Cal macro after each change to check the effectiveness of the change.
After doing this, you will see any changes where one tower may be higher than the other. If this is the case, go back and re-adjust the end stop screws.
It can typically take anywhere from 5-10 iterations of the calibration process in order to get the gap to remain the same at all three pause points compared to the center point. Once the gap is the same at each tower compared to the center, the machine is calibrated and ready to print.