Ender-3 and Novice Upgrades: Eleventh Upgrade (Auto Calibration)
This text has been automatically translated using Google Translate.
The eleventh upgrade is for all who choose not to use glass or have multiple types of print pads.
As already mentioned, glass helps to create a flat surface for printing. If you use a different surface, your printing area may not be perfectly flat. There are various auto calibration sensors and sensors to help you with this.
The cheapest solution was shown in the video below. There is no need to replace the system board or make a bigger leak into the printer.
https://www.youtube.com/watch?v=HJV82NHOY-0
But if you want to spend and do not mind possible promotion of the motherboard, here are a few pieces in which you can invest.
 |  |  |
|---|---|---|
| BLTouch | 3DTouch | PINDA inductive sensor |
| around CZK 850 | around 350 CZK | around 260 CZK |
| The first and most universal is BLTouch. This sensor “taps” the print area, making it independent of the type of print pad. If you decide to replace the 4 mm glass with an original backing before printing, this will not be a problem for this sensor. In case of original motherboard it is necessary to buy a reduction to PIN 27 . | The second is actually the same as the first sensor, only its clone. As a result, its accuracy and quality are questionable. Even in this case it is necessary to buy a reduction to PIN 27 for the original motherboard. | The third is a little limited by the type of printing pad. The printing pad must be made of metal. So if you decide on glass, you're out of luck. If you have a magnetic bed with a metal printing plate, congratulations, this sensor is for you. |
In case of BLTouch and 3DTouch PIN 27 was mentioned (about 60 CZK).
This is a reduction that will disconnect the display from the speaker and this pin number 27 will be used as a servo pin for BLTouch and 3DTouch .
You ask why the capacitive sensor is not listed here?
Good question!
The reason is simple. This sensor is basically sensitive to any object that approaches its tip. Unfortunately, "object" is also dust or hot air.
So, if you warm up the print pad and start scanning, the measured distance will vary depending on how much you blow on the sensor as you watch the printer measure individual points during auto calibration.