Adding a second extruder

Hey,

We're working to get a dual extruder head. I've been looking as some of the firmware and it looks like there is a built in way to configure two extruders but I can't really figure it out. Can anyone help me out.

Ideally, I would like to have 1 pin on the board that outputs LOW when were using tool 1 and HIGH when were using tool 2.

You would use T0 for the first extruder and T1 for the second extruder.
Once the tool value is selected any line representing motion in an E-based code will activate that extruder.

Okay so how would I hook up the second extruder?

RAMPS 1.3 and higher have an extra location for a Pololu stepper driver. They are lableled E0 and E1 on the printed board.
Look at the RAMPS 1.3 or 1.4 Wiki page. There is a drawing on each wiki page about the hookups with mulitple extruders. You treat each extruder as an individual extruder in that each one needs its own complete circuit.

At a minimum you would need another stepper motor, another Pololu stepper driver and another Wade's extruder (or whatever design you want to use. Somehow you will have to join the two extruders and get them at the exact same height. Personally I would mount one of them on a screw adjustable plate so I could raise or lower it as needed.

So then what do i need to configure in the firmware to make it switch extruders? I understand the hardware part but I'm having trouble with the software.

You would have to address that with the different firmware you are going to use.
I thought a few had it already in there but I have never looked for it.

it looks like they have something built in too accommodate dual extruders except I can't find any documentation on how to use that feature. I feel like people built the functionallity into the config files but never design the way to actually make it work. I'm new to the firmwares code and I can figure it out for the life of me.

Adding support for a second extruder is pretty much a DIY project right now. Even if you could find a firmware that supports it, you still would need a gcode generator (i.e. skeinforge) to support it.

There are currently no firmwares which actually support a separate extruder.

Most of them have a little bit of the puzzle, but none of them are finished. Teacup appears the closest, but I can't keep up with every firmware around.


Skeinforge is ready and able to run a separate extruder for support. Just alter the (start/end support) g-code accordingly.