Dual extruder for Mendel 90: I need a little help

Hello,

I have build Mendel 90 printer and I designed a dual extruder. (see picture attached).
As an improvement I want to design a swiveling X carriage because with 2 printheads it is handy if the not printing hot end is lifted a little (1 mm) to avoid collisions with the printed material and no oozing appears. (See attached picturenew.png for my first setup.)

How it works:
The left extruder is extruder no. 1 and the right extruder is extruder no 1.
Default extruder no 1 is is down position. If extruder 2 should print a 12 Volts current should flow through the coil and a metal axis is pushed out and the green lever is rotated to the right. The short end of the lever will push another metal rod and the complete X carriage is swiveled (against the spring pressure) resulting in extruder 2 in down position.

My questions:
How do I tell Slic3er that a current should flow from my Rumba board through the coil when extruder 2 should print?
Which ports do I need on the Rumba board/ WHat do I need to change in the firmware to get this working?
I hope someone has any hints/ideas!

Thanks in advance!

Slic3r lets you add arbitrary gcode at tool changes. You can use M42 to control an arbitrary port as long as it is isn't defined as something else in pins.h.

See [github.com]

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[www.hydraraptor.blogspot.com]

Dear Nophead,

Thanks for your answer, I will look into it .
Apart from the software I am also a little bit in the dark about the electrical hardware.
Is your tric limited to 5 Volts output?
I think a need a powerful force from the coil which sets extruder 2 in down position and thus need 12 Volts through the coil.
At the moment I only use 2 hotends and my Rumba board can manage 3 hotends. My idea was to use this extra "hotend" to put a 12 V
current through the coil to get extruder 2 in "down" position.
Do you think that this is feasable?

Regards,
JWD

PS Big fan of your work

If you remove the third heater definition from pins.h you will be able to control that port with M42 and turn it on and off. You should put a back EMF diode across the coil and be aware that not all solenoids are rated for 100% duty cycle.

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[www.hydraraptor.blogspot.com]