Hi, I started to build lr3 in Finland. I have mostly all parts I need. I have old Anet A6 3d printer and I think that I could take all electronics from there? So my question is can I modify the mainboard program (Marlin) So that extruder driver would do second y job. And can I change thermistor ports that They would work with endstops?
I have no experience with coding 
Btw is there any lr3 builds in Finland?
It looks like that board has only 4 drivers. And because it is not one of the boards we usually use, you will have to configure the firmware yourself.
You can run the LR3 with only 3 axis. But having auto squaring on Z is pretty helpful. That requires an extra driver. Dual Y is also helpful, which requires a 5th.
Getting a board that Ryan sells (a rambo or skr pro v1.2) makes configuration a lot easier and you can add 4 endstops to get autosquaring.
Okay thanks. I chegged prices to here, and I think I try the Anet mainboard first, before buy better one🤔
Here are a few references to help you get started.
With only 4 drivers, you will have to wire your two Y steppers and your two Z steppers in series. You will only use 3 of your 4 drivers in this setup. You will find the wiring diagram for a serial wiring harness on this page. You will need to click on the “Archive” link at the bottom of the page to see the serial wiring diagram.
As for your firmware, your board is billed as a Ramps board. Anet provides the source for a working version of Marlin (for their 3D printer) on this page. This will almost certainly be an older version of Marlin. V1 provides versions of the firmware for the Ramps 1.4 board on this page. You want V1CNC_Ramps. The Lowrider-specific version is for dual endstops, which require five stepper drivers.
The firmware compiles with PlatformIO. Your task will be to meld together the appropriate settings from V1 maintained Marlin source and the ANet maintained source. It is likely that all the required changes will be confined to just two files: configuration.h and configuration_adv.h. Most changes will be just commenting or uncommenting a line. You can use a difference tool like Meld to compare these two files between the different versions of Marlin source to get a good idea of what the settings should be. If possible, it would be best to use the V1CNC_Ramps source and merge in the Anet differences. This will have you running a later version of Marlin.
