Yeah Open TX, is very powerfull. I use it since my first Menzi Muck,
How did you control the tracks ?
For mine, I use a switch over with the back joystick, but loose the 3rd piece boom cylinder and gripper when I use the tracks command.
I'm thinking to put 2 more joystick on the back with L1 and L1, for track control.
I made it, with 6mm gearmotor. The lock is asymetrical but all effort is in front of the coupler, so after more than 220hours, any problem or exessive play.
Coupler wide is 25mm. In front you can see 4 holes for automatic connection.
Number of channels is not a problem with open TX, For this one I use 16 channels only. The external module is disabled.
Here is the wiring diagram of my Engcon EC226. I use 8 wire slip ring
Hello. Good work on the Engcon and the Horus.
I don't think the coupler with gripper is the best way. I did this for my JCB because the EC214 at 1:15 scale is very small. But for a bigger version like your 40t bagger, a separate coupler and gripper version is much better in use. Just my opinion.
In many cases we can use the gripper and keep the bucket.
Here is mine :
https://youtu.be/f9A4Tg7Iksg
Best regards
Sehr interessantes Projekt ! Wir hatten genau die gleichen Ideen ... Hier ist meine ich letztes Jahr gebaut.
Auch im Massstab 1 : 15 
