In this step, we will calibrate the PID temperature control of the hot ends and the nozzle spacing of the dual extruders.
You will need:
- Two spools of filament, different colours (the greater the contrast, the better), preferably ABS.
Download the "Calibration Test.factory" file at the bottom of the page, and double click it to automatically open up the default profile and test model in Simplify3D. The default profile assumes you have ordered the AON with 0.6mm nozzles installed, and that you are using ABS.
If this is not the case, change your nozzle size by first clicking on the "Edit Process Settings" button in the lower right hand corner of the screen.
On the settings screen that pops up, go to the "Extruder" tab, and change the nozzle size to whichever nozzle size is currently installed (0.4/0.6/0.8/1.0/1.2).
Do this for both the T0/Left Extruder and the T1/Right Extruder, as both toolheads will have the same size of nozzle installed when shipped.
If you do not have any ABS on hand, you must also change the temperature settings to match the material that you are using. On the same settings screen, navigate to the "Temperature" tab.
You must consult the material manufacturer for the proper hot end and heated bed temperatures. Some common temperature ranges are listed below:
- Hot End: 180-220C
- Heated Bed: 60C
- Chamber: Off
- Hot End: 220-260C
- Heated Bed: 90-110C
- Chamber: 60+*
- Hot End: 220-280C
- Heated Bed: 60-80C
- Chamber: Off
*As the test print is such a small object and will not warp, we recommend you leave the chamber heater off to avoid the heat-up time.
Once the settings have been changed, you're ready to start.
Hot End PID Tuning
First, run the PID auto-tune tool by going to the "Communication" tab in the machine control panel, and entering the command "M303 E0 S240 C5". This will start to heat the T0/Left Extruder.
Wait for the program to finish the process. You will know the process has finished when you see the following in the communications window:
PID Autotune finished! Place the last Kp, Ki and Kd constants from below into Configuration.h
Take note of the values for Kp, Ki, and Kd.
Store these values by entering the command "M301 PXX.XX IXX.XX DXX.XX", replacing the X's with the values you have recorded. Finally, send the command "M500".
We're now ready for the next step.
Dual Extruder Calibration
In the machine control panel once more, manually heat the extruders to load the material by setting a target temperature, and pressing "On". To heat Tool 0, make sure Tool 0 is selected in the dropdown box above. To heat Tool 1, select it from the dropdown box above before setting the target temperature and pressing "On".
The filament is loaded through the rear panel of your AON - simply push the end of your filament through the two holes and feed it all the way through until you meet resistance. You will then need to unplug the filament guide tube from the extruder by pressing down on the push-fit connector and pulling the tube out, and pull a few more inches of the filament from the tube.
Once the hot ends have reached the target temperature of your material, manually jog the extruder by pressing the "100" button in the "Jog Controls" tab. Now take the end of your filament and push it into the top of the extruder until it catches on the filament drive gears. Now you can push the guide tube back into the push-fit connector.
Advance the extruder in 10mm increments by pressing the "10" button in the machine control panel until you have verified that the filament extrudes without any issues. Repeat this for the other extruder.
Back on the Simplify3D main screen, press "Prepare to Print!" button, and then press "Begin Printing over USB".
Your bed will begin to preheat. This print will print the exterior of the cube with T0 and the infill with T1, allowing you to see the positioning error of the dual extruders in the XY plane. The infill should be perfectly aligned with the inside of the cube without overlapping into the perimeters.
Observe the print as it starts. Your first indicator of calibration errors will be the priming skirt that prints before the cube starts.
At any point, you may choose to stop the calibration print, take a measurement of the error, correct it, and then run the print again to verify the accuracy.
To correct the error, you will enter the command "M218 T1 Xnn.n Ynn.n" where nn.n is the measurement offset in mm to one decimal digit, followed by "M500" to save. The T0/Left extruder positioning is fixed with respect to the firmware, so you must look at how off whatever T1 prints is relative to T0.
For Ynn.n, the default offset spacing is 0. If T1 is printing too far to the back of the printer (+'ve in the Y direction), your nn.n will also be a positive value, vice versa.
For Xnn.n, the default offset spacing is 585mm. If T1 is printing too far to the left, your nn.n will be 585 PLUS whatever the magnitude of the error was. If too far to the right, your nn.n will be 585 MINUS whatever the magnitude of the error was.
There is no need to finish the cube test print for each calibration trial, simply stop the print whenever you notice an error, try correcting the spacing, and run the print again to confirm. Once you are satisfied with the alignment, you're all done!
to learn more about your AON such as the duplication mode feature and controlling the heated chamber.