Muahaha… So I built mine temporarily out to 5x5 so I could cut a half sheet of wood. Then cut out the pieces for the mp3dp I’m slowly putting together.
Worked beautifully even without the middle piers. There is clearly some sag and you have to cut a bit deep to account for it… But if you are just cutting parts out it seems just fine…
Now to print off the printed parts…
does mounting it on the ceiling help with the sag?? 
Don’t forget to invert the Z-Axis 
Pls keep us updated about rigidity and vibration.
It worked just fine. No real issues. Did a nice job with the cuts. It’s about 100f here today so I had a couple times where the z missed steps when drilling holes in the y plate. Probably means I need a better heat sink or fan on it… But taking it slow and drilling holes as several different programs seemed to get through it ok…
I used a couple of old doors as the base. Instant torsion box…
And of course building it off the ceiling and reversing the gravity in the garage as per normal practice…
Lithium grease is quite good and sticks well to the rod. Helped a lot on Z
I bicycle a lot (4500 miles each year) so I used the same grease I use on the bike. Lasts forever and takes a beating. And… I have it already.
