So when I first saw the new LR3 screenshots I originally thought “Oh interesting, it has 3 rails on the X axis”. Took me a while to finally see the back and realize it doesn’t. This put the seed of an idea in my head I couldn’t shake. I really like the new design but I figured “why not make this more difficult for potentially no reason”. With the full length strut plates it’s likely all of this won’t add any stiffness, but I had the tubing already and triangles are good right?
The plan is a 25"x49" cutting area (just to give me a little space for quarter sheets). SKR pro 1.2 controller with a TFT screen. I’ll start on the table once I build the gantry. One other thing I’m going to try just to be difficult (and since this will be a dedicated CNC table) is to put rails on both sides of the Y axis. We’ll see how this works out, if alignment is indeed a pain in the butt it’ll just be a matter of printing out a couple new wheel brackets.
I started by importing the braces and remodeling them with the 3rd rail. The front and rear struts will be the same design as the hole spacing and gap in the braces is the same, the bottom is narrower and will require a narrower strut. These new braces now mount to the XZ plates in 4 places instead of 3. Necessary? Probably not… likely the theme of this build. Like added gussets which probably did more for build plate adhesion than strength. I just flipped the stl for each side.
I have the means to make my own aluminum XZ plates so I modified that dxf for the additional brace pickup point.
Cut these out and drilled them by hand using a printout glued to the aluminum.
I made the braces 2 different parts and filled the holes in all of the middle ones.
Which leads me to where I currently am.
Still have a lot to do, but the major components are printed. I stole my X axis tubing from my old Burly MPCNC as well as my steppers, bearings, and a few other parts.