OK, so I think I’m mostly doing this right. I’m going to have a go at building a Mendel90 going the laser-cut route. (http://www.thingiverse.com/thing:174966)
I want to scale it up so one of my X or Y dimensions is 300. I haven’t bought anything yet so I know I’ll need to come back into the cad files and reconfigure some stuff for my bed components, but I’m just trying to get some ballpark lengths of smooth and threaded rod to order since they’re probably coming on a slow boat from China.
I’ve gathered that it’s more efficient to add to the X dimension, so I’m going with X=300, Y=200, Z=200(probably). But… I’m not entirely sure which configuration options go with X and which go with Y.
I think I need to change these: (as found in the 200x200x200 ‘standard’ build in the Config file)
X_travel = 200;
Y_travel = 200;
Z_travel = 200;
and
bed_depth = 214;
bed_width = 214;
and
bed_holes = [209, 209];
X-travel is kinda easy 
.
I’m assuming Bed_Width = X so I would need to change Bed_Width to 314 (until I actually buy my bed components and can re-spec that part). Unless the Mendel exists in some world where X=Bed_depth. Not sure…
If I have that right, I’m not sure about the Bed_Holes option - I’m just getting up to speed with OpenSCAD and I’m not sure if that means [X,Y] (that seems logical, but…); if so I need to put [309,209] there (again until I get my actual stuff and can re-spec).
I’ll probably try building it a few times in OpenSCAD and see what it spits out, but my computer is so slow it won’t render the final product - all I can really preview is the frame sheet cut diagrams and text output. But if someone can shed some light and save me some iterations, that would be great!
Ugh, and while I’m here… The ReadMe on this branch of the project states that the make_machine python script won’t work for this project and individual SCAD files will have to be recompiled. OK, great, what the heck does that mean?