MendelMax 1.5 Build Log: Part 6, First Light!

Finally, I was able to get the MendelMax Reprap wired up and connected to a PC.

Steps along the way:

I went with 1/2" MDF to mount the heat bed

I drew a simple pattern- I wanted clearance for glass hold down clips, and the center cutout for the termistor

1/2" MDF Cut to shape

MDF Mounted to Y-Axis Slide

Zoom-in detail of  MDF mount on Y-Axis slide

The 1/2" MDF is attached to the Y-Slide using 4x M5 SHCS. The bed can be leveled by alternately tightening and loosening the screws. The way it's mounted it's rigidly affixed. I think as soon as I have the printer running I'm going to update it to add some spring mounts- so the bed can move if there is a head crash.

At this point I could do a very initial bed leveling by manually moving the X and Y axis to make sure the extruder head did not change height over the build plane. I did have to do some adjustments to the bed to get it as level as possible. I'll have to very carefully repeat this step once the machine is functional.

Next, I soldered the power connections and thermistor wires for the hot bed, and screwed it to the MDF.

RAMPS 1.4 board from Gadgets3D.com attached to frame using bracket off of Thingiverse.com

Everything Wired up Prior to tidying up the wires. Note the sweet cable chain on the Y axis also downloaded from Thingiverse (and printed on another printer) Once this printer is running I'll make similar cable chains for the X and Z axis.

Wires Cleaned up, Power Supply Attached (but not plugged in) and Arduino powered over USB

Gadgets3D.com LCD- showing no firmware yet loaded onto RAMPS / Arduino

After everything wired, cleaned up, and ready for first power- I gingerly plugged the USB cable from the Arduino to my old laptop. I didn't plug in the big 12V powersupply that provides the motivation for the steppers and heaters yet, I wanted to make sure all was well with the firmware first. No sparks or smoke- a good first sign.

I downloaded and installed the latest Arduino development environment, and installed the Arduino Mega 2560 drivers. Then, I downloaded the latest Marlin firmware from here.

I did an initial brush through the configuration file before I uploaded the firmware. Since I wasn't really sure of what initial settings are best, I used the recommended settings from the reprap mendelmax configuration page. I also used the modifications for the Gadgets3D LCD panel, described here.

After that, I saved, held my breath, and clicked on the compile/upload button. A minute or two later the LCD panel magically started showing a menu and current updates on the printer!

I downloaded what I've read to be the easiest to use printer interface- pronterface - from this location. I fired it up- and after I entered the correct COM port and Baud rate, it immediately recognized the RAMPS board. Bam. Then, I really held my breath and plugged in the big power supply. Amazingly, no sparks or smoke again. 2 for 2. I initially wanted just to test moving the various axis- unfortunately this is where I hit my first roadblock. I hit the button to manually drive the X axis, and immediately the error came up on both the LCD screen and the PC that the X endstop was hit, eventhough it clearly was not. I believe I need to re-examine how I wired all the endstops (NC or NO), plus whether or not I need a pull-up or pull-down resistor on each on. That'll be the story for another night. In the mean time it's exciting enough just to have it mechanically complete, preliminary wiring down, firmware onboard, and it being recognized by the host computer. Big progress!