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calibrating the bed and end
#1
Question on calibrating the bed and end. Seemecnc has a great manual when it comes to RH heating calibration. Could I use those steps also? The Rostocks have a RAMBO board so I'm not sure if this makes a difference.


18 – Calibrating your Rostock MAX

now it's time to get it calibrated so you can begin printing your army of squirrels and Yoda heads.
In order for the mechanical calibration to be accurate, we need to do the steps with the Rostock
MAX at operating temperature. This means that both the hot end and heated bed must be at the
temperature they'd normally be at while printing.
It's very important that the temperature controlling algorithm in the RAMBo (the PID loop) be
as accurate as possible. To do this, we need to run what is called the “PID Auto tune” routine. This is a
firmware function that you run in order to determine the best values for the P(roportional), I(ntegral)
and D(erivative) values used by the PID loop.
First, let's start the auto tune routine for the hot end:
Send the command “M303 S200”. This begins the auto tune process and when it starts, it
begins to add data to the log window at the bottom of the Repetier-Host display. The target
temperature for this process is 200C (that's what the “S200” is for).
It will begin with the entry, “PID Autotune start”. You'll notice that the temperature in the hot
end will begin to climb. A few minutes later, you'll start to see more information appear in the log
window.
While it's working, click on the “Temperature Curve” tab in the main Repetier-Host window:

Fig. 18-1 shows how well the controller manages temperature over time. The display we're
interested in right now are the red and brown lines. The thin red line represents the actual hot end
temperature and the brown line shows an average of the recorded temperature. After a short time, the
display will look something like this:
You can see the PID auto tune function is “learning” how to better manage the temperature in
the hot end. As time goes on, the actual temperature begins to hold to the center of the average target
temperature.
In a few minutes, the routine will complete, and you'll get output similar to the below example:
12:51:52.455 : bias: 76 d: 76 min: 198.18 max: 204.63
12:52:38.513 : bias: 74 d: 74 min: 197.88 max: 202.22
12:53:21.112 : bias: 72 d: 72 min: 198.18 max: 202.04
12:53:21.112 : Ku: 23.78 Tu: 42.60
12:53:21.116 : Classic PID
12:53:21.116 : Kp: 14.27
12:53:21.116 : Ki: 0.67
12:53:21.116 : Kd: 75.97
12:54:02.565 : bias: 71 d: 71 min: 198.33 max: 201.67
12:54:02.569 : Ku: 27.12 Tu: 41.45
12:54:02.569 : Classic PID
12:54:02.569 : Kp: 16.27

Fig. 18-2:Reaching and holding a target temperature.
The Rostock MAX Assembly Guide, 2nd Edition
12:54:02.569 : Ki: 0.79
12:54:02.569 : Kd: 84.31
12:54:45.247 : bias: 71 d: 71 min: 198.33 max: 201.67
12:54:45.251 : Ku: 27.12 Tu: 42.68
12:54:45.251 : Classic PID
12:54:45.252 : Kp: 16.27
12:54:45.252 : Ki: 0.76
12:54:45.252 : Kd: 86.81
12:54:45.255 : PID Autotune finished ! Place the Kp, Ki and Kd constants in the configuration.h
The values that you're interested in are the “Kp”, “Ki” and “Kd” values. There are three blocks
of these values, each under the heading “Classic PID”. Create an average of all the values (add up all
the Kp values, divide by three. Do the same with the Ki and Kd values) and we'll get them added to the
proper spot in the EEPROM table."
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#2
This appears to be eseentially the same as the informarion posted regarding the PIDs using RH.

Kieth
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