Planning to make a dual filament feeder with only one stepper, software?

Hello there!
I'm new on this forum and also new with 3D printers. I try to build one Cartesian type because I like to develop things my self.
I can see that I'm going to use a double filament feeder. I think its expensive and heavy to use two stepper motors so I thinking about use only one stepper motor and a gear who change which feeder to use. I thinking about a solenoid doing the change-work by mowing the pinion sprocket attached to the stepper from feeder 1. to feeder 2. I'm going to print the prototype. I get back with blueprints. My problem is the maneuver software. How can you get a development of it, perhaps Marlin or Sprinter?

Regard
Ola A.
Sweden

I think this can be "almost" done with existing software and firmware


You connect up what ever activates the solenoid to a spare IO pin via standard electronics (Google solenoid on arduino)
Now you can manually control the solenoid with the G42 command [reprap.org]

In slic3r for eg you now set up two extruders and under custom gcode is the tool change gcode. you should be able to set this with the G42 command above and any retraction/extrusion commands needs to get things in the right place.

Only think im not quite sure about is you need a if statement somewhere, ie e0 solinoid on, or e1 soliniod off... but im sure its do able
may need your own post processor for this...

Nice! Then I have to get on with the constuction.


Regard

Ola A.