I've done a respin of the Gen7-AVR1.5 CCA to support dual extrusion in a convenient form factor. The main point behind it was to line up all of the drivers nicely and be able to attach a heat sink + fan on some nearby guide posts.

You can see a picture of the new layout here.

[www.ubc-rapid.com]

Linking up the heater MOSFET and thermistor to the uC was fairly awkward, and does require 2 flywires, but it was done this way so as to not render any extension boards useless. If I was doing it just for internal use, I would have respun the entire thing, (probably with SM components), with a focus around thermal management of MOSFETS and drivers, but, thems the ropes, as they say. Switching between extension boards and dual extruder support is just a matter of 4 jumpers, so I figured that a good way to go.

The source files can be found here:

[github.com]

Edited 5 time(s). Last edit at 01/14/2014 05:52PM by SteveNovakov.

I did an extension board to support a similar feature and it's unobtrusive with I2C.

BTW, MOSFETs for extruder heaters don't need any kind of passive cooling nor heatsink at all (I use the IRFZ44N in a v1.5 board).

Yep, saw that. We just wanted everything on one board for cooling, as stated. Our concern was not for the extruder heaters but for the bed. We planning on extending our printer to PVC, polyethylene, and hopefully polycarbonate. The bed is going to take several hundred watts (20A + through one mosfet).

We are actually going to move away from the Gen7 and create a board more suited to our needs, I just did this as a temp-fix and figured I'd post it up if somoene else was interested.