BLTouch : Auto Bed Leveling Sensors for 3D Printers

Absolutely the best upgrade to my 3D printer in years. Thought I was cool going to an inductive sensor a few years ago, but the BLTouch beats it hands down--I can use my ENTIRE bed surface again (rather than sticking to that 100 mm square "sweet spot" in the middle).Luckily, I already had experience upgrading the stock z-stop (from a simple micro-switch to the inductive sensor), flashing my firmware, and was also familiar with my board's servo connections (thanks to Google) ... so install took about 10 minutes including the Marlin 1.1.9 configuration tweak (9 of those minutes was just swapping the brown and red wires on the connector to match the pins on my controller board). So, I do understand some of the other reviews that state install and configuration can take some time. But it is well worth a little research and getting under the hood on your firmware. After install and firmware flash, it is a simple matter to set the Z offset (and another firmware flash) and Bob's your uncle.You will definitely need at least the 1m extension, depending on your set up (1m was perfect for my 200x200 Prusa clone) ... not sure when the included short cable would ever be useful. Thought about bumping down to 4 starts for that--but the product is just too darn good (and the options with the 1m cable is like the same price anyway). [Also, make sure you get v3.0 of the sensor--it would appear that v3.1 only works with Marlin v2--which is not fully released yet.]I don't know why I avoided the "physical" style probe (i.e. something actually touching the bed) for so long ... but this works beautifully on all bed types, is accurate anywhere on the bed, and is consistent over multiple probings.

I bought a Creality CR-10s Pro, and it comes with a capacitive auto-leveling sensor. While some people have had great luck with that, many, including myself, have had NO luck with its ability to level the bed. Readings from my capacitive sensor were all over the place, fluctuating as much as 0.4mm in any given direction (randomly). The bed was never level. The Z-offset needed to be dialed in every print, sometimes changing as much as 0.5mm in distance. It meant complete unusability for the Creality.I decided to go ahead and install a BLTouch sensor, as some people had had good luck with them. It's like night and day. The install wasn't super straight-forward on the CR-10s Pro (and the cables supplied here don't have the right connectors for the pro, which requires a JST XH connector for the black and white wires, and individual JST SM connectors for the other three wires), but once I attached things to the proper connectors, all I had to do was uncomment one line of code in the TH3D firmware, flash the new screen firmware, and I immediately have a printer that can reliably print without any tinkering.I am to the point that I was with all my Prusa printers (which use an inductive sensor with much better accuracy than a capacitive sensor), where I can just set the Z offset when I change nozzles or change print bed surfaces, and then forget about it. I now just hit 'print' and walk away. There's no tinkering. There's no coming back to a scratched bed in one corner or a print that didn't stick in another. It's perfect every time.Absolutely well worth the price.

This product works as advertised, with a few caveats. The connection from the extension cable to the mainboard is generally loose and can cause unexpected behavior if not secured. I wedged some thin cardstock in beside it to hold it tight and that finally did the trick. I won't lower the product rating for that since its a known issue in the community and doesn't reflect the actual performance of this genuine and functional BL Touch unit. Some people have attached the correct style of connector for their specific board in their install tutorials. I would not rate the install as "easy" since I do not have pin tools and opted to strip and solder the wires to connect the extension cable to the factory one. Once that was done, I fed the wires through the braided cable management compression tubes down to the mainboard and plugged it it. Having the 4.2.2 mainboard, I didn't require any additional interface equipment (transfer board). Older boards will, and you may want to look for a complete interface kit if you have an older board. This kit doesn't have a mounting bracket for the BL Touch, so I printed my own. Flashing the new firmware from creality.com/download was easy for this model of mainboard (4.2.2 or the newer 4.2.7), I simply erased an SD card, placed the new .BIN file on the SD, inserted it into the printer, and booted it up. After that finished, I wiped the card, loaded some print files, and returned the card to the printer before configuring the new setup since settings will be saved on the SD card. Overall, I am extremely pleased with the performance of the BL Touch and, having fixed my loose connection to the mainboard, the unit itself works perfectly every time. I have since upgraded to the 4.2.7 mainboard, and the unit also works perfectly with that. I have also added OctoPrint on a Raspberry Pi and the bed visualization plugin that displays the mesh data from the BL Touch in a graphical format makes it even easier to fine-tune a perfect base-level print platform so that the automatic bed leveling system has less work to do.