Two Questions on Using An ABL

I have two questions regarding using a BL Touch.

I’ve been 3D printing on my Ender 3 Pro for about seven months. Started out leveling the bed manually using the leveling screws - YUK. Then about three months ago I upgraded to stiffer bed springs, borosilicate glass and updated to Marlin 2 and enabled mesh bed leveling. That was a big improvement and I really like it. I’m now going to add a BL Touch, but before I install it I wanted to ask two questions. Maybe it’s a no brainer and I’m over thinking this, but…

#1 When the ABL is installed is there a way to manually level the bed so it is somewhat level to start with and the BL Touch just fine tunes the offsets? To me if the BL Touch is the new Z stop switch the nozzle will be off the bed a few mm. So do I lower the nozzle via the menu then level the corners??

#2 I have seen reports that when using the BL Touch sometimes it doesn’t work and it appears to be electrical interference from the extrusion heater running and the BL Touch wires picking up that interference. Two fixes were to either wrap the BL Touch wires in a metal shield - not a fan. Or to enable a setting in Marlin to turn the heaters off during probing. I like the idea of turning the heater off and plan on doing that when updating the Marlin firmware for using ABL. BUT is that all or are the other settings needed in the firmware config files or in start g-code to turn the heaters off and on?

Thanks, Larry

#1: yes there is. You can dowload and run 1 of several available manual tramming/leveling files. Dr.VAX (@Irv_Shapiro) has 1 for instance. In fact, manual tramming/leveling is highly recommended with a BL Touch.

#2: I have not had trouble with interference when using my BL Touch, so I can’t offer any advice.

I can suggest you consider running Klipper as your printer’s firmware. I switched a month or so ago and will not go back to Marlin. Mind you, it does require using a Raspberry Pi as the main processor, so that’s an investment you would have to make. You could check out Youtube videos by Nero 3DP.

I started with the BL Touch on my Ender 3 v2 and had nothing but issues. I returned 2 of them and when the 3rd one starting acting up I went with the EZABL. I had done the grounding, shielded cable and all still was rare if it didn’t take several times to get it to make all the probes. The EZABL is a few $ more than the BLTouch but by the time I bought the shielded cable I probably had more money in the BLT.

The gcode to turn off the heater goes in the start code in the slicer.

I took the springs off my bed and went with solid mounts. This has worked pretty well for me but I wish I had bought a set instead of making my own form hardware store parts.

I have a CRTouch from Creality, a little newer. I have had no problems with it since day one.

Thanks all.

I have the BL Touch installed and it’s running just great.

Hardware install and calibration went just fine. Updating the firmware was only slow part to get all the needed settings just right. I’ve update and flashed firmware for this printer a couple times before so it wasn’t my first rodeo, but it’s still the slowest step.


I recommend investigating Klipper. It does require a Raspberry Pi, but it’s great.


I have watched some YouTube videos on Klipper and it is intriguing. I especially like feature to only need to update a config file to make changes. That really simplifies things. Maybe I will someday go that route but for now I’m happy with this setup.


The use of printer.cfg for almost all configuration settings is, in a word, awesome.