I've updated my Ender 3 with V4.2.7 mainboard, BLTouch and 400XL kit (extends the capabilities of your Creality Ender 3 3D Printer to a 400 mm X, 400 mm Y and a 500 mm Z printing platform). Now I need to update the firmware. YouTube did not provide any help: i.e.: out of date, so cryptic as to be unusable. Marlin & Creality had overly complicated, for what I need, solutions. Trying these led only to frustrations! Any ideas?
Without knowing exactly which Youtube videos you've looked at, I think where I would start is by downloading the latest Marlin Fimrware and configuration files for the Ender 3 with 4.2.7 board:
If I were doing your upgrade in your place, I would refer to this video for how to compile the firmware for the correct board. I've had to compile firmware for my Ender 3 a few times and I sometimes forget a step. This video is the best that I've found for showing/reminding me of each step.
Essentially, what I think you need to do is compile your firmware as if it were a stock Ender 3 V2 using the settings files I linked above but then change your print area the configuration.h file to match the X400 x Y400 x Z500 print bed area.
Look for the following:
// The size of the print bed #define X_BED_SIZE 200 #define Y_BED_SIZE 200
Change to the following:
// The size of the print bed #define X_BED_SIZE 400 #define Y_BED_SIZE 400
And then look for
#define Z_MAX_POS 200
and change to:
#define Z_MAX_POS 500
There are other changes you'd need to make to the settings file (refer to the video for those). I haven't done your particular upgrade on my machine, so I'm just guessing those extra couple of changes would work for you.
I've done the board upgrade on my Ender 3 Pro. As I've read the BLTouch is easy to install. I'd go over to the Creality forum/help site. You can open a support ticket. They actively have information on firmware in both "release" and "beta" threads. Look there & see if you can get your answers.
Shortly after my post I found this commercial Marlin site 1). It offers firmware for Creality & other printers. You can order 'off the shelf' firmware or customize it yourself. Customizing is quite easy & self explanatory; 5 min. after submitting my requirements, I received a zip file, which I un-zipped & copied the needed file to my SD card. Then I inserted the SD card into my printer & started it. The printer recognized the new firmware & updated its self.
1) This service is not free. Membership of \$15.00/year, is required.
A quick solution is obtaining a pre configured configuration file for this custom extended version of the Ender 3. While it should be very easy to find configurations for Ender 3 with or without BLTouch, the only difference this extension has is an updated printer volume specification. A ready made configuration is found here (please note that it contains an errand for the maximum build height, change
#define Z_MAX_POS 250 to
#define Z_MAX_POS 500.
The basic changes are:
// The size of the print bed #define X_BED_SIZE 400 #define Y_BED_SIZE 400 Z_MAX_POS 500