The hardest parts of this project were always going to be 1) heating the build plate and 2) acquiring the build plate. Getting one square foot of aluminum, a big heated bed, or even a piece of glass for a normal 3D printer is never a problem. When you make a build plate that's a meter long, things start getting a little harder.

But before you acquire a build plate, you must first design it. Therefore:

Benjamin and banana for scale.

The dimensions of the useful part of the build plate are 25cm by 110 cm. Yes, it's a little bigger than I planned, but I figure why not? The overall dimensions of the build plate 27cm by 112cm. On each long side, there are six holes for M3 screws. You want to support it in the middle, you know...

How to build this build plate

I have access to the Hackaday Design Lab, which gives me access to the 4x8 foot shopbot. A 12x48" sheet of 1/4 inch MIC6 aluminum plate will run me about $150. That's not bad. However, I don't really need MIC6 aluminum - 6061 will do just fine; I'm covering the 'flat' part of this build plate with Kapton and PEI sheet.

If I'm going to build this thing out of 6061, I might as well send the file out to BigBlueSaw. This plate, cut out of 0.25 inch 6061 with basic surface finishing will cost about $200 in quantity one. That's fine.

Here's an interesting fact: this build plate will weigh 18 pounds. This printer is going to easily weigh 70 or 80 pounds.

Build plate file uploaded to hackaday.io

In other news, I've decided on the first print. It's this:

It's designed to fit into the front top aluminum extrusion. I think it's great: it immediately gives the not-at-all sexual name of the machine, while giving a clear demonstration of the capabilities of the machine right up front. Here's the OpenSCAD file for it, with the STL in the project files.

difference(){
    union(){
        cube([500,3,20]);
        
        translate([7,3.1,0]){
        linear_extrude(height=15){
            text("THE LOOOOOOOOOOOOOOOONG D", 
                font = "Liberation Sans:style=Bold", size=20);
        }
    }
        
        difference(){
            translate([0,-1,5])
                cube([500,1.1,10]);
                
                
            translate([0,0,4])    
                rotate([45,0,0])
                    cube([500,1.5,10]);
                    
                translate([0,-3,14.2])     
            rotate([-45,0,0])
                cube([500,1.5,10]);
            
        }
    }
    
    
    translate([5,5,10])
        rotate([90,0,0])
            cylinder(h=10,d=4, $fs=0.01);

    translate([495,5,10])
        rotate([90,0,0])
            cylinder(h=10,d=4, $fs=0.01);    
}