September 2nd, 2013
I finished up most of the wiring. I started printing the endstop mounting brackets using the SainSmart green ABS. I am waiting on an order of extra t-nuts and screws so that I can mount and wire the SainSmart endstops. It is coming along nicely!
September 3rd, 2013
I inserted the USB cable into the Arduino and connected it up to my PC. I then adjusted the driver boards potentiometers to read .4 volts (this optimizes the current limit of the clipper circuitry).
I loaded the 3D test program using the Arduino IDE and found that the motor movement was good. I then loaded the Marlin firmware and attempted to manually move the axis’ with the software and found that the steppers would only stutter. After a quick review I realized that I had not installed the 15 jumpers to the headers under the driver boards. This was causing the RAMPS to try to step the motors too fast. Based on the RAMPS wiki, I needed to put jumpers on all of them.After doing that my axis’ were moving as expected.
September 5th, 2013
With all RAMPS 1.4 boards, there are three controlled 12 volt outputs, which normally control the extruder heater, extruder fan, and heated bed. With a dual extruder, you place the second extruder heater on the second output (where the extruder fan was). This leaves the need hook up the extruder fans somewhere. Some people like to just hard wire them to constantly be on with the unit, but I like to have them speed controlled by the software. A simple circuit allows you to do this. I used this design.
I modified the firmware to reflect the new fan pin (pin 4) and set the dual extruder settings.
September 6th, 2013
I played with several different mounting methods for the QU-BD dual extruders, but could not get a reliable hold with the x-axis bracket and the generic QU-BD extruder bracket.
I ended up cutting out a piece of 1/16" steel sheet and drilled and tapped it to fit to the x-axis bracket and the extruders. After a little bit of sanding and a some clear coat spray, it was done.