With that big of a build plate, make sure you’re using double or triple lead screw for Z… A cantilever like a Makerbot will be a giant floppy springboard.
@Ryan_Carlyle I totally agree. I just haven’t decided how I’m going to do it yet. I want to keep the support bars out of the line of sight from the windows on the printer. But it would be super helpful if i could put them dead center of the bed on the sides. Just not sure yet.
Tuck a leadscrew in each of the front corners and one in the rear center
Challenge is going to be Z stage hardware clashing with XY stage hardware, I think… may need to squeeze some stuff to do that.
Well fun story. In trying to upload files to github, I deleted all of my files and had no backup. Luckily i know my measurements. So I’ll redo it in the next few days. Thanks everybody for he ideas!
The design made popular by maker it in the replicator series and then in the replicator 2 uses linear guide rods with bearing or bushings. On the x-axis, the rods on a replicator are just long enough that the bars “droop” in the middle ever so slightly. Now think of how drastic that would be over a 2 foot span and you see why we need a sturdier design for a larger printer.
Simple rule of thumb for replicator-type designs with two steel rods… length no more than 25x the rod diameter. That limit gives acceptable flex due to typical masses / acceleration forces. Same rule works for a single aluminum extrusion used as a v-slot rail, length should be no more than 25x the width of the extrusion. (So 2020 is good to 500mm, 4040 is good to 1m, etc.)
I have 12mm diameter 500mm it’s stiff like hell
@Zviad_Sulaberidze I personally think you get too much ringing with 12mm/500mm rods, but I guess that’s just a matter of how much moving mass and acceleration you have.