About this app
Maybe you know 'Brian\'s index Nozzle calibration tool' or TAMV or kTAMV (k for klipper) ? These tools use an USB (microscope) camera, often with build in leds for the exposure of the object. The tools make it easyier to determine the XY offsets for the Z-probe or for a multi toolhead setup.
My 3D printer has 2 toolheads, a 3dTouch Z-Probe and runs Klipper.
kTAMV, for Klipper, failed sometimes to detect the nozzle on my printer or the offsets were just off. Sometimes its caused by a not clean nozzle but a new, clean, dark colored nozzle also failed. Its not always clear why it went wrong. Its not possible to manually select a detection method or to tweak the parameters of the used methods. The detection methods are global and not per extruder.
The app uses OPENCV's blob detection or hough circles. All parameters can be tweaked. There is ample opportunity to screw image preparation and nozzle detection up.
Select None (no blob detection) or 1 of the 4 sets of blob detection parameters: Simple, Standard, Relax and Super. Simple is available per extruder and the other 3 are global, thus used for all extruders.
Hough circle detection is added for the sake of completeness. It has much jitter on the nozzle position. Per extruder the selection and preparation method can be selected and remembered or kept at automatic (Find 1st fit).
Automatic find does a 'brick' find, through the detection and preparation methods, until the 1st solution with only 1 blob detection.
When this solution is confirmed during 14 frames the find stops.
With "Find continue" the blob detection is forced to continue with the next method or preparation.
Note: The app is a heavy CPU load and memory consumer. The app will drop camera frames. Within Klipper the webcam frame rate can be set, probably for internal usage in Klipper, but via the network the app still gets the full frame rate (in my case ~14 fps) of the camera.
The app's menu has:
- Disclaimer Use the app at your own risk.
- Find 1st fit Find the first detection which has only 1 solution (blob) from the start.
- Find continue Continue the find with the next method.
- View Save frame to file, Flip frame horizontal or vertical, display processed frame, tweak colors and line size.
- Home axes Home X, Y, Z or XYZ axes.
- Extruder Select an extruder (T0-T7).
- Prepare image Select a preparation method for the nozzle detection, tweak the method.
- Nozzle detection Select a nozzle detection method and tweak its parameters (save/reset).
The detection method BLOB SIMPLE is per extruder. All BLOB methods have the same parameters but different values.
- Preferences Set Ip address, Moonraker port, webcam stream, logging.
- Privacy Policy The app does not collect and share any kind of data.
- Exit Exit the app.
Before you start:
- set all gcode offsets to zero in the Klipper configuration file
- clean all nozzles of any filament particles
- retract the filament, per toolhead, 2 mm so that the filament is not visible as a blob in/on the nozzle
- make sure the microscope camera has a solid pedestal and does not move due to vibrations when the toolhead/bed moves (via the USB cable !!).
I had to 3d print a pedestral, added soft rubber pads to its bottom and pin down the USB cable to the bed before it was stable.
- home all axes before you position the camera on the build plate.
You will have to 'lower' the buildplate before the camera will fit.
Manually adjust the focus of the camera.
Pin the USB cable to the build-plate to prevent very tiny movements !!!
- Select a reference extruder from which the other extruder offsets will be calculated.
If applicable, start with the extruder which has the Z-probe attached too it.
- Note: 'dark' nozzles are much more difficult to detect
